@article {3326, title = {Decentralized Trajectory Tracking Control for Soft Robots Interacting with the Environment}, journal = {IEEE Transactions on Robotics (T-RO).}, volume = {Early Access}, year = {2018}, month = {06/2018}, abstract = {

Despite the classic nature of the problem, trajectory

tracking for soft robots, i.e. robots with compliant elements

deliberately introduced in their design, still presents several

challenges. One of these is to design controllers which can

obtain sufficiently high performance while preserving the physical

characteristics intrinsic to soft robots. Indeed, classic control

schemes using high gain feedback actions fundamentally alter the

natural compliance of soft robots effectively stiffening them, thus

de facto defeating their main design purpose. As an alternative

approach, we consider here to use a low-gain feedback, while

exploiting feedforward components. In order to cope with the

complexity and uncertainty of the dynamics, we adopt a decentralized,

iteratively learned feedforward action, combined with

a locally optimal feedback control. The relative authority of the

feedback and feedforward control actions adapts with the degree

of uncertainty of the learned component. The effectiveness of the

method is experimentally verified on several robotic structures

and working conditions, including unexpected interactions with

the environment, where preservation of softness is critical for

safety and robustness.

}, keywords = {Robotics}, author = {F. Angelini and C. Della Santina and M. Garabini and M. Bianchi and G M Gasparri and G. Grioli and M. G. Catalano and A. Bicchi} } @conference {3325, title = {Dynamic Control of Soft Robots Interacting with the Environment}, booktitle = {IEEE International Conference on Soft Robotics}, year = {2018}, month = {07/2018}, publisher = {IEEE}, organization = {IEEE}, address = {24 - 28 April 2018, Livorno, Italy}, keywords = {Robotics}, doi = {https://doi.org/10.1109/ROBOSOFT.2018.8404895}, url = {https://ieeexplore.ieee.org/abstract/document/8404895}, author = {C. Della Santina and R. K. Katzschmann and A. Bicchi and D. Rus} } @article {2814, title = {Asymmetric Bimanual Coordinate Control of Dual-Arm Exoskeleton Robots for Human Cooperative Manipulations}, journal = {IEEE Transactions on Robotics}, volume = {34}, year = {2017}, month = {11/2017}, chapter = {264}, keywords = {Haptics, Robotics}, doi = {https://doi.org/10.1109/TRO.2017.2765334}, url = {https://ieeexplore.ieee.org/document/8103340}, author = {Z. Li and Z. Chen and A. Ajoudani and C. Yang and C. Su and A. Bicchi} } @article {3153, title = {Choosing Poses for Force and Stiffness Control}, journal = {IEEE Transactions on Robotics}, year = {2017}, month = {06/2017}, abstract = {

In humanoids and other redundant robots interacting with the environment, one can often choose between different configurations and control parameters to achieve a given task. A classic tool to describe specifications of the desired force/displacement behavior in such problems is the stiffness ellipsoid, whose geometry is affected by the choice of parameters in both joint control and redundancy resolution{\textemdash}namely, gains and angles. As is well known, impedance control techniques can regulate gains to realize any desired shape of the Cartesian stiffness ellipsoid at the end-effector, so that robot geometry selection could appear secondary. However, humans do not use this possibility: To control the stiffness of our arms, we predominantly use arm configurations. Why is that, and does it makes sense to do the same in robots? To understand this discrepancy, we provide a more complete analysis of the task-space force/deformation behavior of compliant redundant arms to illustrate why the arm geometry plays a dominant role in interaction capabilities of robots. We introduce the notion of allowable Cartesian force/displacement ({\textquotedblleft}stiffness feasibility{\textquotedblright}) regions (SFR) for compliant robots with given torque boundaries. We show that different robot configurations modify such regions and explore the role of robot geometry in achieving an appropriate SFR for the task at hand. The novel concepts and definitions are first illustrated in simulations. Experimental results are then provided to verify the effectiveness of the proposed Cartesian force and stiffness control.

}, keywords = {Robotics}, doi = {10.1109/TRO.2017.2708087}, url = {http://ieeexplore.ieee.org/document/7951027/}, author = {A. Ajoudani and N. G. Tsagarakis and A. Bicchi} } @article {3119, title = {Controlling Soft Robots: Balancing Feedback and Feedforward Elements}, journal = {IEEE Robotics and Automation Magazine}, volume = {24}, year = {2017}, note = {

This work is supported by European Commission grant H2020-ICT-645599 ({\textquotedblleft}SOMA{\textquotedblright}: SOft Manipulation) and European Research Council Advanced grant 291166 ({\textquotedblleft}SoftHands{\textquotedblright}).

}, month = {05/2017}, pages = {75 - 83}, abstract = {

Soft robots (SRs) represent one of the most significant recent evolutions in robotics. Designed to embody safe and natural behaviors, they rely on compliant physical structures purposefully designed to embody desirable and sometimes variable impedance characteristics. This article discusses the problem of controlling SRs. We start by observing that most of the standard methods of robotic control{\textemdash}e.g., high-gain robust control, feedback linearization, backstepping, and active impedance control{\textemdash}effectively fight against or even completely cancel the physical dynamics of the system, replacing them with a desired model. This defeats the purpose of introducing physical compliance. After all, what is the point of building soft actuators if we then make them stiff by control? An alternative to such approaches can be conceived by observing humans, who can obtain good motion accuracy and repeatability while maintaining the intrinsic softness of their bodies. In this article, we show that an anticipative model of human motor control, using a feedforward action combined with low-gain feedback, can be used to achieve human-like behavior. We present an implementation of such an idea that uses iterative learning control. Finally, we present the experimental results of the application of such learned anticipative control to a physically compliant robot. The control application achieves the desired behavior much better than a classical feedback controller used for comparison.

}, keywords = {Robotics}, issn = {1070-9932}, doi = {10.1109/MRA.2016.2636360}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7930438}, author = {C. Della Santina and M. Bianchi and G. Grioli and F. Angelini and M. G. Catalano and M. Garabini and A. Bicchi} } @article {3045, title = {Coordination Control of a Dual-arm Exoskeleton Robot Using Human Impedance Transfer Skills}, journal = {IEEE Trans. Systems Man and Cybernetics: Systems}, year = {2017}, month = {06/2017}, abstract = {

This paper has developed a coordination control method for a dual-arm exoskeleton robot based on human impedance transfer skills, where the left (master) robot arm extracts the human limb impedance stiffness and position profiles, and then transfers the information to the right (slave) arm of the exoskeleton. A computationally efficient model of the arm endpoint stiffness behavior is developed and a co-contraction index is defined using muscular activities of a dominant antagonistic muscle pair. A reference command consisting of the stiffness and position profiles of the operator is computed and realized by one robot in real-time. Considering the dynamics uncertainties of the robotic exoskeleton, an adaptive-robust impedance controller in task space is proposed to drive the slave arm tracking the desired trajectories with convergent errors. To verify the robustness of the developed approach, a study of combining adaptive control and human impedance transfer control under the presence of unknown interactive forces is conducted. The experimental results of this paper suggest that the proposed control method enables the subjects to execute a coordination control task on a dual-arm exoskeleton robot by transferring the stiffness from the human arm to the slave robot arm, which turns out to be effective.

}, keywords = {Robotics}, doi = {10.1109/TSMC.2017.2706694}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7944582}, author = {B. Huang and Z. Li and X. Wu and A. Ajoudani and A. Bicchi and J. Liu} } @conference {3218, title = {Design and characterization of a novel high-compliance spring for robots with soft joints}, booktitle = {IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}, year = {2017}, publisher = {IEEE}, organization = {IEEE}, address = {Munich, Germany, 3-7 July 2017}, abstract = {

Low stiffness elements have a number of applications in Soft Robotics, from Series Elastic Actuators (SEA) to torque sensors for compliant systems. In its general formulation, the design problem of elastic components is complex and depends on several variables: material properties, load range, shape factor and size constraints. Consequently, most of the spring designs presented in literature are based on heuristics or are optimized for specific working conditions. This work presents the design study and characterization of a scalable spoked elastic element with hinge tip constraints. We compared the proposed design with three existing spring principles, showing that the spoked solution is the convenient option for low-stiffness and low shape factor elastic elements. Therefore, a design analysis on the main scaling parameters of the spoked spring, namely number of spokes and type of constraints, is presented. Finally, an experimental characterization has been conducted on physical prototypes. The agreement among simulations and experimental results demonstrates the effectiveness of the proposed concept.

}, keywords = {Robotics}, doi = {10.1109/AIM.2017.8014029}, url = {http://ieeexplore.ieee.org/document/8014029/}, author = {F. Negrello and M. G. Catalano and M. Garabini and M. Poggiani and D. G. Caldwell and N. G. Tsagarakis and A. Bicchi} } @conference {3219, title = {Design, control and validation of the variable stiffness exoskeleton FLExo}, booktitle = {International Conference on Rehabilitation Robotics (ICORR)}, year = {2017}, pages = {539 - 546}, publisher = {IEEE}, organization = {IEEE}, address = {London, UK, 17-20 July 2017}, abstract = {

In this paper we present the design of a one degree of freedom assistive platform to augment the strength of upper limbs. The core element is a variable stiffness actuator, closely reproducing the behavior of a pair of antagonistic muscles. The novelty introduced by this device is the analogy of its control parameters with those of the human muscle system, the threshold lengths. The analogy can be obtained from a proper tuning of the mechanical system parameters. Based on this, the idea is to control inputs by directly mapping the estimation of the muscle activations, e.g. via ElectroMyoGraphic(EMG) sensors, on the exoskeleton. The control policy resulting from this mapping acts in feedforward in a way to exploit the muscle-like dynamics of the mechanical device. Thanks to the particular structure of the actuator, the exoskeleton joint stiffness naturally results from that mapping. The platform as well as the novel control idea have been experimentally validated and the results show a substantial reduction of the subject muscle effort.

}, keywords = {Robotics}, doi = {10.1109/ICORR.2017.8009304}, url = {http://ieeexplore.ieee.org/document/8009304/}, author = {S. Mghames and M. Laghi and C. Della Santina and M. Garabini and M. G. Catalano and G. Grioli and A. Bicchi} } @conference {3106, title = {Design of an Under-Actuated Wrist Based on Adaptive Synergies}, booktitle = {IEEE International Conference of Robotics and Automation, ICRA2017}, year = {2017}, publisher = {IEEE}, organization = {IEEE}, address = {Singapore, 29 May-3 June 2017}, abstract = {

An effective robotic wrist represents a key enabling element in robotic manipulation, especially in prosthetics. In this paper, we propose an under-actuated wrist system, which is also adaptable and allows to implement different under-actuation schemes. Our approach leverages upon the idea of soft synergies - in particular the design method of adaptive synergies - as it derives from the field of robot hand design. First we introduce the design principle and its implementation and function in a configurable test bench prototype, which can be used to demonstrate the feasibility of our idea. Furthermore, we report on results from preliminary experiments with humans, aiming to identify the most probable wrist pose during the pre-grasp phase in activities of daily living. Based on these outcomes, we calibrate our wrist prototype accordingly and demonstrate its effectiveness to accomplish grasping and manipulation tasks.

}, keywords = {Haptics, Robotics}, doi = {10.1109/ICRA.2017.7989789}, url = {http://ieeexplore.ieee.org/document/7989789/}, author = {S. Casini and V. Tincani and G. Averta and M. Poggiani and C. Della Santina and E. Battaglia and M. G. Catalano and M. Bianchi and G. Grioli and A. Bicchi} } @article {3214, title = { Enhancing Adaptive Grasping Through a Simple Sensor-Based Reflex Mechanism }, journal = {IEEE Robotics and Automation Letters}, volume = {2}, year = {2017}, month = {07/2017}, pages = {1664 - 1671}, abstract = {

This paper presents an approach to achieve adaptive grasp of unknown objects whose position is only approximately known via point-cloud data. We exploit the adaptability of a soft robotic hand which can autonomously conform to the shape of a grasped object if properly approached. Once a grasp approach has been preliminarily planned based only on rough estimates of the object position, the hand is shaped to a pregrasp configuration. Before closing the hand, a sensor-based algorithm is applied that corrects the relative hand-object posture so as to enhance the probability that the object is uniformly approached by all fingers, thus avoiding undesired premature contacts. The algorithm minimizes the distance between the hand{\textquoteright}s fingerpads and the object by continuously controlling both the wrist pose and orientation and the hand closure. Experimental studies with a Kuka-LWR arm and a Pisa/IIT Softhand illustrate the benefit of the developed technique and the improvement in grasping performance with respect to open-loop execution of grasps planned on the basis of prior RGB-D cues only.

}, keywords = {Haptics, Robotics}, doi = {10.1109/LRA.2017.2681122}, url = {http://ieeexplore.ieee.org/document/7875417/}, author = {Luberto, E. and Y. Wu and G. Santaera and M Gabiccini and A. Bicchi} } @conference {3220, title = {Estimating Contact Forces from Postural Measures in a class of Under-Actuated Robotic Hands}, booktitle = {IEEE International Conference of Intelligent Robots and Systems (IROS2017)}, year = {2017}, publisher = {IEEE}, organization = {IEEE}, address = {Vancouver, Canada, September 24{\textendash}28, 2017}, keywords = {Robotics}, author = {C. Della Santina and C. Piazza and G. Santaera and G. Grioli and M. G. Catalano and A. Bicchi} } @article {3309, title = {Grasp Performance of a Soft Synergy-Based Prosthetic Hand: A Pilot Study}, journal = { IEEE Transactions on Neural Systems and Rehabilitation Engineering}, volume = {25}, year = {2017}, month = {12/2017}, pages = {2407 - 2417}, abstract = {

Current prosthetic hands are frequently rejected in part due to limited functionality and versatility. We assessed the feasibility of a novel prosthetic hand, the SoftHand Pro (SHP), whose design combines soft robotics and hand postural synergies. Able-bodied subjects (n = 23) tracked cursor motion by opening and closing the SHP and performed a grasp-lift-hold-release (GLHR) task with a sensorized cylindrical object of variable weight. The SHP control was driven by electromyographic (EMG) signals from two antagonistic muscles. Although the time to perform the GLHR task was longer for the SHP than native hand for the first few trials (10.2 {\textpm} 1.4 s and 2.13 {\textpm} 0.09 s, respectively), performance was much faster on subsequent trials (~5 s). The SHP steady-state grip force was significantly modulated as a function of object weight (p \<; 0.001). For the native hand, however, peak and steady-state grip forces were modulated to a greater extent (+68\% and +91\%, respectively). These changes were mediated by the modulation of EMG amplitude and co-contraction. These data suggest that the SHP has a promise for prosthetic applications and point-to-design modifications that could improve the SHP.

}, keywords = {Haptics, Robotics}, issn = {1534-4320}, doi = {10.1109/TNSRE.2017.2737539}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=8094246}, author = {A. S. Gailey and Godfrey, S.B. and R. Breighner and K. Andrews and K. Zhao and A. Bicchi and M. Santello} } @article {2841, title = {An Integrated Approach to Characterize the Behavior of a Human Fingertip in Contact with a Silica Window}, journal = {IEEE Transactions on Haptics}, volume = {10}, year = {2017}, month = {01/2017}, pages = {123-129}, abstract = {

Understanding the mechanisms of human tactual perception represents a challenging task in haptics and humanoid robotics. A classic approach to tackle this issue is to accurately and exhaustively characterize the mechanical behavior of human fingertip. The output of this characterization can then be exploited to drive the design of numerical models, which can be used to investigate in depth the mechanisms of human sensing. In this work, we present a novel integrated measurement technique and experimental set up for in vivo characterization of the deformation of the human fingertip at contact, in terms of contact area, force, deformation, and pressure distribution. The device presented here compresses the participant{\textquoteright}s fingertip against a flat surface, while the aforementioned measurements are acquired and experimental parameters such as velocity, finger orientation, and displacement (indentation) controlled. Experimental outcomes are then compared and integrated with the output of a 3D finite element (FE) model of the human fingertip, built upon existing validated models. The agreement between numerical and experimental data represents a validation for our approach.

}, keywords = {Haptics, Robotics}, issn = {1939-1412}, doi = { 10.1109/TOH.2016.2614679}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7579582}, author = {M. L. D{\textquoteright}Angelo and F. Cannella and M. Bianchi and M. D{\textquoteright}Imperio and E. Battaglia and M. Poggiani and G. Rossi and A. Bicchi and D. G. Caldwell} } @article {3002, title = {On the Minimum-Time Control Problem for Differential Drive Robots with Bearing Constraints}, journal = {Journal of Optimization Theory and Applications}, year = {2017}, month = {04/2017}, pages = {1-27}, abstract = {

This paper presents a study of analysis of minimum-time trajectories for a differential drive robot equipped with a fixed and limited field-of-view camera, which must keep a given landmark in view during maneuvers. Previous works have considered the same physical problem and provided a complete analysis/synthesis for the problem of determining the shortest paths. The main difference in the two cost functions (length vs. time) lays on the rotation on the spot. Indeed, this maneuver has zero cost in terms of length and hence leads to a 2D shortest path synthesis. On the other hand, in case of minimum time, the synthesis depends also on the orientations of the vehicle. In other words, the not zero cost of the rotation on the spot maneuvers leads to a 3D minimum-time synthesis. Moreover, the shortest paths have been obtained by exploiting the geometric properties of the extremal arcs, i.e.,\ straight lines, rotations on the spot, logarithmic spirals and involute of circles. Conversely, in terms of time, even if the extremal arcs of the minimum-time control problem are exactly the same, the geometric properties of these arcs change, leading to a completely different analysis and characterization of optimal paths. In this paper, after proving the existence of optimal trajectories and showing the extremal arcs of the problem at hand, we provide the control laws that steer the vehicle along these arcs and the time-cost along each of them. Moreover, this being a crucial step toward numerical implementation, optimal trajectories are proved to be characterized by a finite number of switching points between different extremal arcs, i.e.,\ the concatenations of extremal arcs with infinitely many junction times are shown to violate the optimality conditions.

}, keywords = {Robotics}, doi = { 10.1007/s10957-017-1110-7}, url = {http://download.springer.com/static/pdf/641/art\%253A10.1007\%252Fs10957-017-1110-7.pdf?originUrl=http\%3A\%2F\%2Flink.springer.com\%2Farticle\%2F10.1007\%2Fs10957-017-1110-7\&token2=exp=1492507070~acl=\%2Fstatic\%2Fpdf\%2F641\%2Fart\%25253A10.1007\%25252Fs10957-017-111}, author = {A. Cristofaro and Salaris, P. and L. Pallottino and Giannoni, F. and A. Bicchi} } @conference {3158, title = {Modular One-to-many Clutchable Actuator for a Soft Elbow Exosuit}, booktitle = { International Conference on Rehabilitation Robotics (ICORR 2017)}, year = {2017}, month = {07/2017}, pages = {1679-1685}, address = {London, UK, July 17 - 20, 2017}, keywords = {Robotics}, doi = {10.1109/ICORR.2017.8009489}, author = {M. Canesi and M. Xiloyannis and A. Ajoudani and A. Bicchi and L. Masia} } @conference {3087, title = {Noninteracting Constrained Motion Planning and Control for Robot Manipulators}, booktitle = {IEEE International Conference of Robotics and Automation, ICRA2017}, year = {2017}, pages = {4038 - 4043}, publisher = {IEEE}, organization = {IEEE}, abstract = {

In this paper we present a novel geometric approach
to motion planning for constrained robot systems.
This problem is notoriously hard, as classical sampling-based
methods do not easily apply when motion is constrained in
a zero-measure submanifold of the configuration space. Based
on results on the functional controllability theory of dynamical
systems, we obtain a description of the complementary spaces
where rigid body motions can occur, and where interaction
forces can be generated, respectively. Once this geometric setting
is established, the motion planning problem can be greatly
simplified. Indeed, we can relax the geometric constraint, i.e.,
replace the lower{\textendash}dimensional constraint manifold with a fulldimensional
boundary layer. This in turn allows us to plan
motion using state-of-the-art methods, such as RRT*, on points
within the boundary layer, which can be efficiently sampled. On
the other hand, the same geometric approach enables the design
of a completely decoupled control scheme for interaction forces,
so that they can be regulated to zero (or any other desired
value) without interacting with the motion plan execution.
A distinguishing feature of our method is that it does not
use projection of sampled points on the constraint manifold,
thus largely saving in computational time, and guaranteeing
accurate execution of the motion plan. An explanatory example
is presented, along with an experimental implementation of the
method on a bimanual manipulation workstation.

}, keywords = {Robotics}, doi = {10.1109/ICRA.2017.7989463}, url = {http://ieeexplore.ieee.org/document/7989463/}, author = {M. Bonilla and L. Pallottino and A. Bicchi} } @article {3138, title = {Online Model Based Estimation of Complete Joint Stiffness of Human Arm}, journal = {IEEE Robotics and Automation Letters}, volume = {3}, year = {2017}, month = {01/2018}, pages = {84 - 91}, abstract = {

The endpoint stiffness of the human arm has been long recognized as a key component ensuring the quasi-static stability of the arm physical interactions with the external world. Similarly, the understanding of the joint stiffness behavior can provide complementary insights, e.g., on the underlying stiffness regulation principles across different joints including the nullspace stiffness profiles. Traditionally, the experimental modeling and estimation of the human arm joint stiffness is achieved by the transformation of the identified arm endpoint stiffness to the joint coordinates. Due to the underlying kinematic redundancy, the obtained joint stiffness matrix is rank-deficient which implies that the information in the joint stiffness matrix is incomplete. While in robotics applications this issue can be addressed by designing a desired nullspace stiffness behavior through appropriate projections, the use of a similar technique in the identification of human joint stiffness profile is meaningless. Hence, the first objective of this work is to address this issue by developing a novel technique to identify the complete and physiologically meaningful joint stiffness of human arm. Second, we present a model-based online estimation technique to estimate the seven-dimensional complete joint stiffness in various arm poses and activation levels of the two dominant arm muscles that correspond to the geometric and volume modifications of the joint stiffness profile, respectively.

}, keywords = {Haptics, Robotics}, doi = {10.1109/LRA.2017.2731524}, url = {http://ieeexplore.ieee.org/document/7990237/}, author = {C. Fang and A. Ajoudani and A. Bicchi and N. G. Tsagarakis} } @conference {3157, title = {Online Model Based Estimation of Complete Joint Stiffness of Human Arm}, booktitle = {IEEE International Conference of Intelligent Robots and Systems (IROS2017)}, year = {2017}, address = {Vancouver, Canada, September 24{\textendash}28, 2017}, keywords = {Robotics}, author = {C. Fang and A. Ajoudani and A. Bicchi and N. G. Tsagarakis} } @article {3216, title = {Postural Hand Synergies during Environmental Constraint Exploitation}, journal = {Fronters in Neurorobotics}, year = {2017}, month = {08/2017}, abstract = {

Humans are able to intuitively exploit the shape of an object and environmental constraints to achieve stable grasps and perform dexterous manipulations. In doing that, a vast range of kinematic strategies can be observed. However, in this work we formulate the hypothesis that such ability can be described in terms of a synergistic behavior in the generation of hand postures, i.e., using a reduced set of commonly used kinematic patterns. This is in analogy with previous studies showing the presence of such behavior in different tasks, such as grasping. We investigated this hypothesis in experiments performed by six subjects, who were asked to grasp objects from a flat surface. We quantitatively characterized hand posture behavior from a kinematic perspective, i.e., the hand joint angles, in both pre-shaping and during the interaction with the environment. To determine the role of tactile feedback, we repeated the same experiments but with subjects wearing a rigid shell on the fingertips to reduce cutaneous afferent inputs. Results show the persistence of at least two postural synergies in all the considered experimental conditions and phases. Tactile impairment does not alter significantly the first two synergies, and contact with the environment generates a change only for higher order Principal Components. A good match also arises between the first synergy found in our analysis and the first synergy of grasping as quantified by previous work. The present study is motivated by the interest of learning from the human example, extracting lessons that can be applied in robot design and control. Thus, we conclude with a discussion on implications for robotics of our findings.

}, keywords = {Haptics, Robotics}, doi = {https://doi.org/10.3389/fnbot.2017.00041}, url = {https://www.frontiersin.org/articles/10.3389/fnbot.2017.00041/full}, author = {C. Della Santina and M. Bianchi and G. Averta and S. Ciotti and V. Arapi and S. Fani and E. Battaglia and M. G. Catalano and M. Santello and A. Bicchi} } @conference {3215, title = {Preliminary results toward a naturally controlled multi-synergistic prosthetic hand}, booktitle = {International Conference on Rehabilitation Robotics (ICORR)}, year = {2017}, abstract = {

Robotic hands embedding human motor control principles in their mechanical design are getting increasing interest thanks to their simplicity and robustness, combined with good performance. Another key aspect of these hands is that humans can use them very effectively thanks to the similarity of their behavior with real hands. Nevertheless, controlling more than one degree of actuation remains a challenging task. In this paper, we take advantage of these characteristics in a multi-synergistic prosthesis. We propose an integrated setup composed of Pisa/IIT SoftHand 2 and a control strategy which simultaneously and proportionally maps the human hand movements to the robotic hand. The control technique is based on a combination of non-negative matrix factorization and linear regression algorithms. It also features a real-time continuous posture compensation of the electromyographic signals based on an IMU. The algorithm is tested on five healthy subjects through an experiment in a virtual environment. In a separate experiment, the efficacy of the posture compensation strategy is evaluated on five healthy subjects and, finally, the whole setup is successfully tested in performing realistic daily life activities.

}, keywords = {Robotics}, isbn = {978-1-5386-2296-4}, doi = {10.1109/ICORR.2017.8009437}, url = {http://ieeexplore.ieee.org/abstract/document/8009437/}, author = {M. Rossi and C. Della Santina and C. Piazza and G. Grioli and M. G. Catalano and A. Bicchi} } @article {2875, title = {The Quest for Natural Machine Motion: An Open Platform to Fast-Prototyping Articulated Soft Robots}, journal = {IEEE Robotics and Automation Magazine }, volume = {24}, year = {2017}, note = {

Open access

e wish to thank Samuele Batazzi, Fabio Bonomo, Alberto
Brando, Andrea Di Basco, Tommaso Pardi, Riccardo Persichi-
ni, and Alessandro Raugi for their valuable support in the
development of the hardware prototype. This work was sup-
ported by SOFTPRO (grant 688857) and SOMA (grant
645599){\textemdash}projects of the European Commission{\textquoteright}s Horizon
2020 research program{\textemdash}and by Walk-Man grant 611832.
Support also came from the European Research Council
under an Advanced Grant for {\textquotedblleft}SoftHands: A Theory of Soft
Synergies for a New Generation of Artificial Hands{\textquotedblright} (grant
ERC-291166).
}, pages = {48 - 56}, abstract = {
Soft robots are one of the most significant recent evolutions in robotics. They rely on compliant physical structures purposefully designed to embody desired characteristics. Since their introduction, they have shown remarkable applicability in overcoming their rigid counterparts in such areas as interaction with humans, adaptability, energy efficiency, and maximization of peak performance. Nonetheless, we believe
that research on novel soft robot applications is still slowed by the difficulty in obtaining or developing a working soft robot structure to explore novel applications.
In this article, we present the Natural Machine Motion Initiative (NMMI), a modular open platform that aims to provide the scientific community with tools for fast and easy prototyping of articulated soft robots. Such a platform is composed of three main open hardware modules: the Qbmoves variable-stiffness actuators (VSAs) to build the main robotic structure, soft end effectors (EEs) to interact with the world, and a pool of application-specific add-ons. We also discuss many novel uses of the platform to rapidly prototype (RP) and test new robotic structures with original soft capabilities, and we propose NMMI- based experiments.
}, keywords = {Robotics}, issn = {1070-9932 }, doi = {10.1109/MRA.2016.2636366}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7857692}, author = {C. Della Santina and C. Piazza and Gasparri, G. M. and M. Bonilla and M. G. Catalano and G. Grioli and M. Garabini and A. Bicchi} } @article {3258, title = {The SoftHand Pro-H: A Hybrid Body-Controlled, Electrically Powered Hand Prosthesis for Daily Living and Working }, journal = {IEEE Robotics and Automation Magazine}, year = {2017}, note = {

This work was supported by the European Commission project (Horizon 2020 research program) SOFTPRO 688857, the European Research Council under the Advanced Grant SoftHands {\textquotedblleft}A Theory of Soft Synergies for a New Generation of Artificial Hands,{\textquotedblright} ERC-291166, and the Proof of Concept Project SoftHand Pro-H, ERC-2016-PoC 727536.\ 

}, month = {11/2017}, keywords = {Haptics, Robotics}, issn = {1070-9932}, doi = {10.1109/MRA.2017.2751662}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8110634}, author = {C. Piazza and M. G. Catalano and S. B. Godfrey and M. Rossi and G. Grioli and M. Bianchi and K. Zhao and A. Bicchi} } @conference {3156, title = {Tele-Impedance with Force Feedback under Communication Time Delay}, booktitle = {IEEE International Conference of Intelligent Robots and Systems (IROS2017)}, year = {2017}, publisher = {IEEE}, organization = {IEEE}, address = {Vancouver, Canada, September 24{\textendash}28, 2017}, keywords = {Robotics}, author = {M. Laghi and A. Ajoudani and M. G. Catalano and A. Bicchi} } @proceedings {2992, title = {Towards Minimum-Information Adaptive Controllers for Robot Manipulators}, year = {2017}, publisher = {IEEE}, address = {May 24{\textendash}26 2017, Seattle USA}, abstract = {

The aim of this paper is to move a step in the direction of determining the minimum amount of information needed to control a robot manipulator within the framework of adaptive control. Recent innovations in the state of the art show how global asymptotic trajectory tracking can be achieved despite the presence of uncertainties in the kinematic and dynamic models of the robot. However, a clear distinction between
which parameters can be included among the uncertainties, and which parameters can not, has not been drawn yet. Since most of the adaptive control algorithms are built on linearly parameterized models, we propose to reformulate the problem as finding a procedure to determine whether and how a given dynamical system can be linearly parameterized with respect to a specific set of parameters.
Within this framework, we show how the trajectory tracking problem of a manipulator can be accomplished with the only knowledge of the number of joints of the manipulator. As an illustrative example, we present the end-effector trajectory tracking control of a robot initialized with the kinematic model of a different robot.

}, keywords = {Robotics}, doi = {https://doi.org/10.23919/ACC.2017.7963602}, url = {https://ieeexplore.ieee.org/document/7963602}, author = {T. Marcucci and C. Della Santina and M Gabiccini and A. Bicchi} } @article {3137, title = {WALK-MAN: A High-Performance Humanoid Platform for Realistic Environments}, journal = {Journal of Field Robotics}, volume = {34}, year = {2017}, month = {06/2017}, pages = {1 - 34}, abstract = {

In this work, we present WALK-MAN, a humanoid platform that has been developed to operate in realistic unstructured environment, and demonstrate new skills including powerful manipulation, robust balanced locomotion, high-strength capabilities, and physical sturdiness. To enable these capabilities, WALK-MAN design and actuation are based on the most recent advancements of series elastic actuator drives with unique performance features that differentiate the robot from previous state-of-the-art compliant actuated robots. Physical interaction performance is benefited by both active and passive adaptation, thanks to WALK-MAN actuation that combines customized high-performance modules with tuned torque/velocity curves and transmission elasticity for high-speed adaptation response and motion reactions to disturbances. WALK-MAN design also includes innovative design optimization features that consider the selection of kinematic structure and the placement of the actuators with the body structure to maximize the robot performance. Physical robustness is ensured with the integration of elastic transmission, proprioceptive sensing, and control. The WALK-MAN hardware was designed and built in 11 months, and the prototype of the robot was ready four months before DARPA Robotics Challenge (DRC) Finals. The motion generation of WALK-MAN is based on the unified motion-generation framework of whole-body locomotion and manipulation (termed loco-manipulation). WALK-MAN is able to execute simple loco-manipulation behaviors synthesized by combining different primitives defining the behavior of the center of gravity, the motion of the hands, legs, and head, the body attitude and posture, and the constrained body parts such as joint limits and contacts. The motion-generation framework including the specific motion modules and software architecture is discussed in detail. A rich perception system allows the robot to perceive and generate 3D representations of the environment as well as detect contacts and sense physical interaction force and moments. The operator station that pilots use to control the robot provides a rich pilot interface with different control modes and a number of teleoperated or semiautonomous command features. The capability of the robot and the performance of the individual motion control and perception modules were validated during the DRC in which the robot was able to demonstrate exceptional physical resilience and execute some of the tasks during the competition.

}, keywords = {Robotics}, issn = {1556-4967}, doi = {10.1002/rob.21702}, url = {http://onlinelibrary.wiley.com/doi/10.1002/rob.21702/epdf}, author = {N. G. Tsagarakis and D. G. Caldwell and F. Negrello and W. Choi and L. Baccelliere and V. G. Loc and J. Noorden and L. Muratore and A. Margan and A. Cardellino and L. Natale and E. Mingo Hoffman and H. Dallali and N. Kashiri and J. Malzahn and J. Lee and P. Kryczka and D. Kanoulas and M. Garabini and M. G. Catalano and M. Ferrati and V. Varricchio and L. Pallottino and C. Pavan and A. Bicchi and A Settimi and A. Rocchi and A. Ajoudani} } @inbook {2819, title = {Actuators for Soft Robotics}, booktitle = {Springer Handbook of Robotics}, volume = {B}, year = {2016}, pages = {499-530}, publisher = {Springer}, organization = {Springer}, abstract = {

Although we do not know as yet how robots of the future will look like exactly, most of us are sure that they will not resemble the heavy, bulky, rigid machines dangerously moving around in old-fashioned industrial automation. There is a\ growing consensus, in the research community as well as in expectations from the public, that robots of the next generation will be physically compliant and adaptable machines, closely interacting with humans and moving safely, smoothly and efficiently\ {\textendash} in other terms, robots will be soft.

This chapter discusses the design, modeling and control of actuators for the new generation of soft robots, which can replace conventional actuators in applications where rigidity is not the first and foremost concern in performance. The chapter focuses on the technology, modeling, and control of lumped parameters of soft robotics, that is,\ systems of discrete, interconnected, and compliant elements. Distributed parameters, snake-like and continuum soft robotics, are presented in Chap.\ 20, while Chap.\ 23 discusses in detail the biomimetic motivations that are often behind soft robotics.

}, keywords = {Robotics}, issn = {978-3-319-32550-7}, doi = {10.1007/978-3-319-32552-1_21}, url = {http://link.springer.com/chapter/10.1007/978-3-319-32552-1_21}, author = {A Albu-Schaeffer and A. Bicchi} } @article {2844, title = {Assessment of Myoelectric Controller Performance and Kinematic Behavior of a Novel Soft Synergy-inspired Robotic Hand for Prosthetic Applications}, journal = {Frontiers in Neurorobotics}, volume = {10}, year = {2016}, month = {10/2016}, abstract = {

Myoelectric-artificial limbs can significantly advance the state of the art in prosthetics, since they can be used to control mechatronic devices through muscular activity in a way that mimics how the subjects used to activate their muscles before limb loss. However, surveys indicate that dissatisfaction with the functionality of terminal devices underlies the widespread abandonment of prostheses. We believe that one key factor to improve acceptability of prosthetic devices is to attain human-likeness of prosthesis movements, a goal which is being pursued by research on social and human-robot interactions. Therefore, to reduce early abandonment of terminal devices, we propose that controllers should be designed such as to ensure effective task accomplishment in a natural fashion. In this work, we have analyzed and compared the performance of three types of myoelectric controller algorithms based on surface electromyography to control an under-actuated and multi-degrees of freedom prosthetic hand, the SoftHand Pro. The goal of the present study was to identify the myoelectric algorithm that best mimics the native hand movements. As a preliminary step, we first quantified the repeatability of the SoftHand Pro finger movements and identified the electromyographic recording sites for able-bodied individuals with the highest signal-to-noise ratio from two pairs of muscles, i.e. flexor digitorum superficialis/extensor digitorum communis, and flexor carpi radialis/extensor carpi ulnaris. Able-bodied volunteers were then asked to execute reach-to-grasp movements, while electromyography signals were recorded from flexor digitorum superficialis/extensor digitorum communis as this was identified as the muscle pair characterized by high signal-to-noise ratio and intuitive control. Subsequently, we tested three myoelectric controllers that mapped electromyography signals to position of the SoftHand Pro. We found that a differential electromyography-to-position mapping ensured the highest coherence with hand movements. Our results represent a first step towards a more effective and intuitive control of myoelectric hand prostheses.

}, keywords = {Haptics, Robotics}, doi = {10.3389/fnbot.2016.00011}, url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5066092/}, author = {S. Fani and M. Bianchi and S. Jain and J. Pimenta Neto and S. Boege and G. Grioli and A. Bicchi and M. Santello} } @article {2685, title = {The Change in Fingertip Contact Area as a Novel Proprioceptive Cue}, journal = {Current Biology}, volume = {26}, year = {2016}, month = {05/2016}, pages = {1159{\textendash}1163}, abstract = {

Humans, many animals, and certain robotic hands have deformable fingertip pads. Deformable pads have the advantage of conforming to the objects that are being touched, ensuring a stable grasp for a large range of forces and shapes. Pad deformations change with finger displacements during touch. Pushing a finger against an external surface typically provokes an increase of the gross contact area, potentially providing a relative motion cue, a situation comparable to looming in vision. The rate of increase of the area of contact also depends on the compliance of the object. Because objects normally do not suddenly change compliance, participants may interpret an artificially induced variation in compliance, which coincides with a change in the gross contact area, as a change in finger displacement, and consequently they may misestimate their finger{\textquoteright}s position relative to the touched object. To test this, we asked participants to compare the perceived displacements of their finger while contacting an object varying pseudo-randomly in compliance from trial to trial. Results indicate a bias in the perception of finger displacement induced by the change in compliance, hence in contact area, indicating that participants interpreted the altered cutaneous input as a cue to proprioception. This situation highlights the capacity of the brain to take advantage of knowledge of the mechanical properties of the body and of the external environment.

}, keywords = {Haptics, Robotics}, doi = {10.1016/j.cub.2016.02.052}, url = {http://www.sciencedirect.com/science/article/pii/S0960982216301348}, author = {A. Moscatelli and M. Bianchi and A. Serio and A. Terekhov and V. Hayward and M. Ernst and A. Bicchi} } @article {2481, title = {Convergence Analysis of Distributed Set-Valued Information Systems}, journal = {IEEE Transactions on Automatic Control}, volume = {61}, year = {2016}, month = {06/2016}, pages = {1477 - 1491}, abstract = {
This paper focuses on the convergence of information in distributed systems of agents communicating over a network.
The information on which the convergence is sought is not represented by real numbers, as often in the literature, rather by sets. The dynamics of the evolution of information across the network is accordingly described by set-valued iterative maps. While the study of convergence of set-valued iterative maps is highly complex in general, this paper focuses on Boolean maps, which are comprised of arbitrary combinations of unions, intersections, and complements of sets. For these important class of systems, we provide tools to study both global and local convergence. A distributed geographic information system, leading to successful information reconstruction from partial and corrupted data, is used to illustrate the applications of the proposed methods.
}, keywords = {Embedded Control, Robotics}, doi = {10.1109/TAC.2015.2480176}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7272075}, author = {A. Fagiolini and N. Dubbini and S. Martini and A. Bicchi} } @conference {2921, title = {Development of a robotic teaching interface for human to human skill transfer}, booktitle = {IEEE International Conference on Intelligent Robots and Systems}, year = {2016}, month = {11/2016}, pages = {710-716}, publisher = {IEEE}, organization = {IEEE}, address = {Danjeon, Korea}, keywords = {Robotics}, doi = {10.1109/IROS.2016.7759130}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006355804\&doi=10.1109\%2fIROS.2016.7759130\&partnerID=40\&md5=7f982e3eb493c1a6047d1dcc2acbe208}, author = {Yang, C. and P. Liang and A. Ajoudani and Z. Li and A. Bicchi} } @article {2652, title = {Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands}, journal = {Physics of Life Reviews}, volume = {17}, year = {2016}, month = {07/2016}, pages = {1-23}, keywords = {Haptics, Robotics}, url = {http://www.sciencedirect.com/science/article/pii/S1571064516000269}, author = {M. Santello and M. Bianchi and M Gabiccini and E. Ricciardi and G. Salvietti and D Prattichizzo and M. Ernst and A. Moscatelli and H. Jorntell and A. Kappers and K. Kyriakopulos and A Albu-Schaeffer and C. Castellini and A. Bicchi} } @conference {2545, title = {A Modular Compliant Actuator for Emerging High Performance and Fall-Resilient Humanoids}, booktitle = {15th IEEE RAS Humanoids Conference (HUMANOIDS2015)}, year = {2016}, note = {

This work is supported by the WALK-MAN FP7-ICT-2013-10 European Commission project.

}, publisher = {IEEE}, organization = {IEEE}, keywords = {Robotics}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7363567}, author = {F. Negrello and M. Garabini and M. G. Catalano and J. Malzahn and D. G. Caldwell and A. Bicchi and N. G. Tsagarakis} } @article {2627, title = {No More Heavy Lifting: Robotic Solutions to the Container Unloading Problem}, journal = {IEEE Robotics and Automation Magazine}, volume = {23}, year = {2016}, month = {08/2016}, chapter = {94}, keywords = {Robotics}, doi = {https://doi.org/10.1109/MRA.2016.2535098}, url = {https://ieeexplore.ieee.org/document/7553531}, author = {T. Stoyanov and N. Vaskeviciusz and C. A. Mueller and T. Fromm and R. Krug and V. Tincani and R. Mojtahedzadeh and S. Kunaschk and R. M. Ernits and D. R. Canelhas and M. Bonilla and S. Schwertfeger and M. Bonini and H. Halfar and K. Pathak and M. Rohde and G Fantoni and A. Bicchi and A. Birk and A. Lilienthal and W. Echelmeyer} } @conference {2655, title = {Reflex Control of the Pisa/IIT SoftHand during Object Slippage}, booktitle = {IEEE International Conference of Robotics and Automation (ICRA2016)}, year = {2016}, pages = {1972 - 1979}, publisher = {IEEE}, organization = {IEEE}, address = {Stockholm, Sweden}, abstract = {

In this work, to guarantee the Pisa/IIT SoftHand{\textquoteright}s

grasp robustness against slippage, three reflex control modes,

namely Current, Pose and Impedance, are implemented and

experimentally evaluated. Towards this objective, ThimbleSense

fingertip sensors are designed and integrated into the thumb

and middle fingers of the SoftHand for real-time detection and

control of the slippage. Current reflex regulates the restoring

grasp forces of the hand by modulating the motor{\textquoteright}s current

profile according to an update law. Pose and Impedance reflex

modes instead replicate this behaviour by implementing an

impedance control scheme. The difference between the two

latter is that the stiffness gain in Impedance reflex mode is

being varied in addition to the hand pose, as a function of

the slippage on the fingertips. Experimental setup also includes

a seven degrees-of-freedom robotic arm to realize consistent

trajectories (e.g. lifting) among three control modes for the sake

of comparison. Different test objects are considered to evaluate

the efficacy of the proposed reflex modes in our experimental

setup. Results suggest that task-appropriate restoring forces

can be achieved using Impedance reflex due to its capability

in demonstrating instantaneous and rather smooth reflexive

behaviour during slippage. Preliminary experiments on five

healthy human subjects provide evidence on the similarity of the

control concepts exploited by the humans and the one realized

by the Impedance reflex, highlighting its potential in prosthetic

applications.

}, keywords = {Haptics, Robotics}, doi = {10.1109/ICRA.2016.7487344}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7487344}, author = {A. Ajoudani and E. Hocaoglu and Altobelli, A and M. Rossi and E. Battaglia and N G Tsagarakis and A. Bicchi} } @conference {2889, title = {Robust Optimization of System Compliance for Physical Interaction in Uncertain Scenarios}, booktitle = {IEEE International Conference on Humanoid Robots (HUMANOIDS2016)}, year = {2016}, note = {
This work was supported by the European Commission projects (FP7 framework) Walk-Man and the European Commission Grant no. H2020- ICT-645599 {\textquotedblleft}SOMA{\textquotedblright}: SOft MAnipulation
}, publisher = {IEEE}, organization = {IEEE}, address = {Cancun, Mexico, 15-17 Nov. 2016 }, abstract = {

Compliance in robot design and control is often introduced to improve the robot performance in tasks where interaction with environment or human is required. However a rigorous method to choose the correct level of compliance is still not available. In this work we use robust optimization as a tool to select the optimal compliance value in a robotenvironment interaction scenario under uncertainties. We propose an approach that can be profitably applied on a variety of tasks, e.g.manipulation tasks or locomotion tasks. The aim is to minimize the forces of interaction considering model constraints and uncertainties. Numerical results show that: i) in case of perfect knowledge of the environment stiff robots behave better in terms of force minimization, ii) in case of uncertainties the optimal stiffness of the robot is lower than the previous case and optimal solutions provide a faster task accomplishment, iii) the optimal stiffness decreases as a function of the uncertainty measure. Experiments are carried out in a realistic set-up in case of bi-manual object handover.

}, keywords = {Robotics}, isbn = {978-1-5090-4718-5 }, doi = { 10.1109/HUMANOIDS.2016.7803381}, url = {http://ieeexplore.ieee.org/document/7803381/}, author = {Gasparri, G. M. and F. Fabiani and M. Garabini and L. Pallottino and M. G. Catalano and G. Grioli and R. Persichini and A. Bicchi} } @conference {3086, title = {Soft Robots that Mimic the Neuromusculoskeletal System}, booktitle = {3rd International Conference on NeuroRehabilitation (ICNR2016)}, volume = {Converging Clinical and Engineering Research on Neurorehabilitation}, year = {2016}, month = {10/2016}, pages = {259-263}, publisher = {Springer}, organization = {Springer}, abstract = {

In motor control studies, the question on which
parameters human beings and animals control through their
nervous system has been extensively explored and discussed,
and several hypotheses proposed. It is widely acknowledged
that useful inputs in this problem could be provided by
developing artificial replication of the neuromusculoskeletal
system, to experiment different motor control hypothesis. In
this paper we present such device, which reproduces many of
the characteristics of an agonistic-antagonistic muscular pair
acting on a joint.

}, keywords = {Robotics}, doi = { 10.1007/978-3-319-46669-9_45}, url = {http://link.springer.com/chapter/10.1007/978-3-319-46669-9_45}, author = {M. Garabini and C. Della Santina and M. Bianchi and M. G. Catalano and G. Grioli and A. Bicchi} } @inbook {2865, title = {The SoftHand Pro: Translation from Robotic Hand to Prosthetic Prototype}, booktitle = {Converging Clinical and Engineering Research on Neurorehabilitation II}, volume = {15}, number = {Biosystems \& Biorobotics }, year = {2016}, note = {

Proceedings of the 3rd International Conference on NeuroRehabilitation (ICNR2016), October 18-21, 2016, Segovia, Spain

}, pages = {469-473}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

This work presents the translation from a humanoid robotic hand to a prosthetic prototype and its first evaluation in a set of 9 persons with amputation. The Pisa/IIT SoftHand is an underactuated hand built on the neuroscientific principle of motor synergies enabling it to perform natural, human-like movements and mold around grasped objects with minimal control input. These features motivated the development of the SoftHand Pro, a prosthetic version of the SoftHand built to interface with a prosthetic socket. The results of the preliminary testing of the SoftHand Pro showed it to be a highly functional design with an intuitive control system. Present results warrant further testing to develop the SoftHand Pro.

}, keywords = {Haptics, Robotics}, issn = {978-3-319-46668-2}, doi = {10.1007/978-3-319-46669-9_78}, url = {http://link.springer.com/chapter/10.1007/978-3-319-46669-9_78}, author = {S. B. Godfrey and M. Bianchi and K. Zhao and M. G. Catalano and R. Breighner and A. Theuer and K. Andrews and G. Grioli and M. Santello and A. Bicchi} } @conference {2725, title = {SoftHand Pro-D: Matching Dynamic Content of Natural User Commands with Hand Embodiment for Enhanced Prosthesis Control}, booktitle = {IEEE International Conference of Robotics and Automation (ICRA2016)}, year = {2016}, note = {

softpro soma softhands

}, pages = {3516 - 3523}, publisher = {IEEE}, organization = {IEEE}, address = {Stockholm, Sweden, May 16-21}, abstract = {

State of the art of hand prosthetics is divided between simple and reliable gripper-like systems and sophisticate hi-tech poly-articular hands which tend to be complex both in their design and for the patient to operate. In this paper, we introduce the idea of decoding different movement intentions of the patient using the dynamic frequency content of the control signals in a natural way. We move a step further showing how this idea can be embedded in the mechanics of an underactuated soft hand by using only passive damping components.

In particular we devise a method to design the hand hardware to obtain a given desired motion. This method, that we call of the dynamic synergies, builds on the theory of linear descriptor systems, and is based on the division of the hand movement in a slow and a fast components. We use this method to evolve the design of the Pisa/IIT SoftHand in a prototype prosthesis which, while still having 19 degrees of freedom and just one motor, can move along two different synergistic directions of motion (and combinations of the two), to perform either a pinch or a power grasp. Preliminary experimental results are presented, demonstrating the effectiveness of the proposed design

}, keywords = {Haptics, Robotics}, doi = {10.1109/ICRA.2016.7487532}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7487532}, author = {C. Piazza and C. Della Santina and M. G. Catalano and G. Grioli and M. Garabini and A. Bicchi} } @inbook {3155, title = {Teleimpedance Control: Overview and application}, booktitle = {Human and Robot Hands }, volume = {Springer Series on Touch and Haptic Systems}, year = {2016}, pages = {151-169}, chapter = {9}, abstract = {

In previous chapters, human hand and arm kinematics have been analyzed through a synergstic approach and the underlying concepts were used to design robotic systems and devise simplified control algorithms. On the other hand, it is well-known that synergies can be studied also at a muscular level as a coordinated activation of multiple muscles acting as a single unit to generate different movements. As a result, muscular activations, quantified through Electromyography (EMG) signals can be then processed and used as direct inputs to external devices with a large number of DOFs. In this chapter, we present a minimalistic approach based on tele-impedance control, where EMGs from only one pair of antagonistic muscle pair are used to map the users postural and stiffness references to the synergy-driven anthropomorphic robotic hand, described in chapter 6. In this direction, we first provide an overview of the teleimpedance control concept which forms the basis for the development of the hand controller. Eventually, experimental results evaluate the effectiveness of the teleimpedance control concept in execution of the tasks which require significant dynamics variation or are executed in remote environments with dynamic uncertainties.

}, keywords = {Robotics}, issn = {978-3-319-26705-0}, doi = {10.1007/978-3-319-26706-7}, author = {A. Ajoudani and S. B. Godfrey and N. G. Tsagarakis and A. Bicchi} } @article {2544, title = {ThimbleSense: a fingertip-wearable tactile sensor for grasp analysis}, journal = {IEEE Transactions on Haptics}, volume = {9}, year = {2016}, note = {
This work was partially supported by the European Community funded projects WEARHAP, PACMAN and SOMA (contracts 601165, 600918 and 645599 respectively), by the ERC Advanced Grant no. 291166 SoftHands
}, month = {03/2016}, pages = {121-133}, abstract = {

Accurate measurement of contact forces between hand and grasped objects is crucial to study sensorimotor control during grasp and manipulation. In this work we introduce ThimbleSense, a prototype of individual-digit wearable force/torque sensor based on the principle of intrinsic tactile sensing. By exploiting the integration of this approach with an active marker-based motion capture system, the proposed device simultaneously measures absolute position and orientation of the fingertip, which in turn yields measurements of contacts and force components expressed in a global reference frame. The main advantage of this approach with respect to more conventional solutions is its versatility. Specifically, ThimbleSense can be used to study grasping and manipulation of a wide variety of objects, while still retaining complete force/torque measurements. Nevertheless, validation of the proposed device is a necessary step before it can be used for experimental purposes. In this work we present the results of a series of experiments designed to validate the accuracy of ThimbleSense measurements and evaluate the effects of distortion of tactile afferent inputs caused by the device{\textquoteright}s rigid shells on grasp forces.

}, keywords = {Haptics, Robotics}, issn = {1939-1412}, doi = {10.1109/TOH.2015.2482478}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7294702}, author = {E. Battaglia and M. Bianchi and Altobelli, A and G. Grioli and M. G. Catalano and A. Serio and M. Santello and A. Bicchi} } @conference {2881, title = {Toward an Adaptive Foot for Natural Walking}, booktitle = {International Conference on Humanoid Robots (HUMANOIDS2016)}, year = {2016}, address = {Cancun, Mexico, November 15-17, 2016}, abstract = {

Many walking robot presented in literature stand
on rigid flat feet, with a few notable exceptions that embed
flexibility in their feet to optimize the energetic cost of walking.
This paper proposes a novel adaptive robot foot design, whose
main goal is to ease the task of standing and walking on uneven
terrains. After explaining the rationale behind our design
approach, we present the design of the SoftFoot, a foot able
to comply with uneven terrains and to absorb shocks thanks to
its intrinsic adaptivity, while still being able to rigidly support
the stance, maintaining a rather extended contact surface,
and effectively enlarging the equivalent support polygon. The
paper introduces the robot design and prototype and presents
preliminary validation and comparison versus a rigid flat foot
with comparable footprint and sole.

}, keywords = {Robotics}, doi = {10.1109/HUMANOIDS.2016.7803423}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7803423}, author = {C. Piazza and C. Della Santina and Gasparri, G. M. and M. G. Catalano and G. Grioli and M. Garabini and A. Bicchi} } @conference {2883, title = {Toward whole-body loco-manipulation: Experimental results on multi-contact interaction with the Walk-Man robot}, booktitle = {IEEE International Conference of Intelligent Robots and Systems (IROS 2016)}, year = {2016}, publisher = {IEEE}, organization = {IEEE}, address = {Danjeon, Korea, October 10-14 2016}, abstract = {

In this paper a quasi-static framework for optimally controlling the contact force distribution is experimentally verified with the full-size compliant humanoid robot Walk-Man. The proposed approach is general enough to cope with multi-contact scenarios, i.e. robot-environment interactions occurring on feet and hands, up to the more general case of whole-body loco-manipulation, in which the robot is in contact with the environment also with the internal limbs, with a consequent loss of contact force controllability. Experimental tests were conducted with the Walk-Man robot (i) standing on flat terrain, (ii) standing on uneven terrain and (iii) interacting with the environment with both feet and a hand touching a vertical wall. Moreover, the influence of unmodeled weight on the robot, and the combination with a higher priority Cartesian tasks are shown. Results are presented also in the attached video.

}, keywords = {Robotics}, doi = {10.1109/IROS.2016.7759225}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7759225}, author = {E. Farnioli and M Gabiccini and A. Bicchi} } @article {2904, title = {Variable Stiffness Actuators: Review on Design and Components}, journal = { IEEE/ASME Transactions on Mechatronics }, volume = {21}, year = {2016}, month = {10/2016}, pages = {2418 - 2430}, abstract = {

Variable stiffness actuators (VSAs) are complex mechatronic devices that are developed to build passively compliant, robust, and dexterous robots. Numerous different hardware designs have been developed in the past two decades to address various demands on their functionality. This review paper gives a guide to the design process from the analysis of the desired tasks identifying the relevant attributes and their influence on the selection of different components such as motors, sensors, and springs. The influence on the performance of different principles to generate the passive compliance and the variation of the stiffness are investigated. Furthermore, the design contradictions during the engineering process are explained in order to find the best suiting solution for the given purpose. With this in mind, the topics of output power, potential energy capacity, stiffness range, efficiency, and accuracy are discussed. Finally, the dependencies of control, models, sensor setup, and sensor quality are addressed.

}, keywords = {Robotics}, doi = {10.1109/TMECH.2015.2501019}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7330025}, author = {S. Wolf and G. Grioli and O. Eiberger and W. Friedl and M. Grebenstein and H. Hoppner and E. Burdet and D. G. Caldwell and R. Carloni and M. G. Catalano and D. Lefeber and S. Stramigioli and N. G. Tsagarakis and M. Van Damme and R. Van Ham and B. Vanderborght and L. C. Visser and A. Bicchi and A Albu-Schaeffer} } @conference {2788, title = { WALK-MAN humanoid lower body design optimization for enhanced physical performance}, booktitle = {IEEE International Conference of Robotics and Automation (ICRA2016)}, year = {2016}, pages = {1817 - 1824}, publisher = {IEEE}, organization = {IEEE}, address = {Stockholm, Sweden, May 16-21, 2016 }, abstract = {
The deployment of robots to assist in environments hostile for humans during emergency scenarios require robots to demonstrate enhanced physical performance, that includes adequate power, adaptability and robustness to physical interactions and efficient operation. This work presents the design and development of the lower body of the new high performance humanoid WALK-MAN, a robot developed recently to assist in disaster response scenarios. The paper introduces the details of the WALK-MAN lower-body, highlighting the innovative design optimization features considered to maximize the leg performance. Starting from the general lower body specifications the objectives of the design and how they were addressed are introduced, including the selection of the leg kinematics, the arrangement of the actuators and their integration with the leg structure to maximize the range of motion, reduce the leg mass and inertia, and shape the leg mass distribution for better dynamic performance. Physical robustness is ensured with the integration of elastic transmission and impact energy absorbing covers. Experimental walking trials demonstrate the correct operation of the legs while executing a walking gait.
}, keywords = {Robotics}, doi = {10.1109/ICRA.2016.7487327}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7487327}, author = {F. Negrello and M. Garabini and M. G. Catalano and P. Kryczka and W. Choi and D. G. Caldwell and A. Bicchi and N. G. Tsagarakis} } @conference {2723, title = {A Wearable Fabric-based Display for Haptic Multi-Cue Delivery}, booktitle = {IEEE Haptics Symposium}, year = {2016}, publisher = {IEEE}, organization = {IEEE}, address = {Philadelphia, USA, April 8-11, 2016}, abstract = {

Softness represents one of the most informative

haptic properties, which plays a fundamental role in both

everyday tasks and more complex procedures. Thus, it is not

surprising that much effort has been devoted to designing haptic

systems able to suitably reproduce this information. At the

same time, wearability has gained an increasing importance as

a novel paradigm to enable a more effective and naturalistic

human robot interaction. Capitalizing upon our previous works

on grounded softness devices, in this paper we present the

Wearable Fabric Yielding Display (W-FYD), a fabric-based

tactile display for multi-cue delivery that can be worn by

user{\textquoteright}s finger. W-FYD enables to implement both passive and

active tactile exploration. Different levels of stiffness can be

reproduced by modulating the stretching state of a fabric

through two DC motors. An additional vertical degree of

freedom is implemented through a lifting mechanism, which

enables to convey softness stimuli to the user{\textquoteright}s finger pad.

Furthermore, a sliding effect on the finger can be also induced.

Experiments with humans show the effectiveness of W-FYD for

haptic multi-cue delivery.

}, keywords = {Haptics, Robotics}, doi = {10.1109/HAPTICS.2016.7463190}, url = {http://ieeexplore.ieee.org/search/searchresult.jsp?queryText=A\%20Wearable\%20Fabric-based\%20Display\%20for\%20Haptic\%20Multi-Cue\%20Delivery\&newsearch=true}, author = {M. Bianchi and E. Battaglia and M. Poggiani and S. Ciotti and A. Bicchi} } @conference {2454, title = {Characterization of Nonlinear Finger Pad Mechanics for Tactile Rendering}, booktitle = {IEEE World Haptics Conference}, year = {2015}, note = {

softhands, werahap

}, pages = {63-68}, address = {Chicago, USA, 22-25 June 2015}, abstract = {

The computation of skin forces and deformations for\ tactilerendering\ requires an accurate model of the extremely\ nonlinear\ behavior of the skin. In this work, we investigate the\ characterization\ of\ fingermechanics\ with the goal of designing accurate\ nonlinear\ models for\ tactilerendering. First, we describe a measurement setup that enables the acquisition of contact force and contact area in the context of controlled\ finger\ indentation experiments. Second, we describe an optimization procedure that estimates the parameters of strain-limiting deformation models that match best the acquired data. We show that the acquisition setup allows the measurement of force and area information with high repeatability, and the estimation method reaches\ nonlinear\ models that match the measured data with high accuracy.

}, keywords = {Haptics, Robotics}, doi = {10.1109/WHC.2015.7177692}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7177692}, author = {E. Miguel and M. L. D{\textquoteright}Angelo and F. Cannella and M. Bianchi and M Memeo and A. Bicchi and D. G. Caldwell and M. A. Otaduy} } @conference {2560, title = {Design and Realization of the CUFF - Clenching Upper-Limb Force Feedback Wearable Device for Distributed Mechano-Tactile Stimulation of Normal and Tangential Skin Forces}, booktitle = {IEEE International Conference of Intelligent Robots and Systems - IROS2015}, year = {2015}, note = {

The authors want to thank Cosimo della Santina, Andrea Di Basco, Riccardo Persichini and Fabio Bonomo for their really valuable support in the development of the hardware prototype. This work is supported in part by the European Research Council under the Advanced Grant SoftHands {\textquotedblleft}A Theory of Soft Synergies for a New Generation of Artificial Hands{\textquotedblright} (no. ERC-291166), and by the EU FP7 project (no. 601165) {\textquotedblleft}WEARable HAPtics for Humans and Robots (WEARHAP)

}, pages = {1186 - 1193}, publisher = {IEEE}, organization = {IEEE}, address = {Hamburg, Germany, 28 Sept - 2 Oct 2015}, abstract = {

Rendering forces to the user is one of the main goals of haptic technology. While most force-feedback interfaces are robotic manipulators, attached to a fixed frame and designed to exert forces on the users while being moved, more recent haptic research introduced two novel important ideas. On one side, cutaneous stimulation aims at rendering haptic stimuli at the level of the skin, with a distributed, rather than, concentrated approach. On the other side, wearable haptics focuses on highly portable and mobile devices, which can be carried and worn by the user as the haptic equivalent of an mp3 player. This paper presents a light and simple wearable device (CUFF) for the distributed mechano-tactile stimulation of the user{\textquoteright}s arm skin with pressure and stretch cues, related to normal and tangential forces, respectively. The working principle and the mechanical and control implementation of the CUFF device are presented. Then, after a basic functional validation, a first application of the device is shown, where it is used to render the grasping force of a robotic hand (the Pisa/IIT SoftHand). Preliminary results show that the device is capable to deliver in a reliable manner grasping force information, thus eliciting a good softness discrimination in users and enhancing the overall grasping experience.

}, keywords = {Robotics}, doi = {10.1109/IROS.2015.7353520}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7353520\&newsearch=true\&queryText=Design\%20and\%20Realization\%20of\%20the\%20CUFF\%20-\%20Clenching\%20Upper-Limb\%20Force\%20Feedback\%20Wearable\%20Device\%20for\%20Distributed\%20Mechano-Tactile\%20Stimulatio}, author = {S. Casini and M. Morvidoni and M. Bianchi and M. G. Catalano and G. Grioli and A. Bicchi} } @conference {2537, title = {Dexterity augmentation on a synergistic hand: the Pisa/IIT SoftHand+}, booktitle = {15th IEEE RAS Humanoids Conference (HUMANOIDS2015)}, year = {2015}, note = {

Softhands, SOMA

Best Interactive Paper Award

}, pages = {497 - 503}, publisher = {IEEE}, organization = {IEEE}, address = {Seoul, Korea, November 3 - 5, 2015}, abstract = {
Soft robotics and under-actuation were recently demonstrated as good approaches for the implementation of humanoid robotic hands. Nevertheless, it is often difficult to increase the number of degrees of actuation of heavily under-actuated hands without compromising their intrinsic simplicity. In this paper we analyze the Pisa/IIT SoftHand and its underlying logic of adaptive synergies, and propose a method to double its number of degree of actuation, with a very reduced impact on its mechanical complexity. This new design paradigm is based on constructive exploitation of friction phenomena.
Based on this method, a novel prototype of under-actuated robot hand with two degrees of actuation is proposed, named Pisa/IIT SoftHand+. A preliminary validation of the prototype follows, based on grasping and manipulation examples of some objects.
}, keywords = {Haptics, Robotics}, doi = {10.1109/HUMANOIDS.2015.7363595}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7363595}, author = {C. Della Santina and G. Grioli and M. G. Catalano and Brando, A. and A. Bicchi} } @conference {2538, title = {Effect of Homogenous Object Stiffness on Tri-digit Grasp Properties}, booktitle = {37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC2015)}, year = {2015}, note = {
This work is supported in part by the European Research Council under the Advanced Grant SoftHands {\textquotedblleft}A Theory of Soft Synergies for a New Generation of Artificial Hands{\textquotedblright} no. ERC-291166 and under the EU FP7 project WEARHAP {\textquotedblleft}WEARable HAPtics for Humans and Robots{\textquotedblright} no. 601165.
}, pages = {6704 - 6707}, publisher = {IEEE}, organization = {IEEE}, address = { Milano, Italy, August 25th-29th, 2015}, abstract = {
This paper presents experimental findings on how humans modulate their muscle activity while grasping objects of varying levels of compliance. We hypothesize that one of the key abilities that allows humans to successfully cope with uncertainties while grasping compliant objects is the ability to modulate muscle activity to control both grasp force and stiffness in a way that is coherent with the task. To that end, subjects were recruited to perform a grasp and lift task with a tripod-grasp device with contact surfaces of variable compliance. Subjects performed the task under four different compliance conditions while surface EMG from the main finger flexor and extensor muscles was recorded along with force and torque data at the contact points. Significant increases in the extensor muscle (the antagonist in the task) and co-contraction levels were found with increasing compliance at the contact points. These results suggest that the motor system may employ a strategy of increasing cocontraction, and thereby stiffness, to counteract the decreased stability in grasping compliant objects. Future experiments will examine the extent to which this phenomenon is also related to specific task features, such as precision versus power grasp and object weight.
}, keywords = {Haptics, Robotics}, doi = {10.1109/EMBC.2015.7319931}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7319931}, author = {S. B. Godfrey and Altobelli, A and M. Rossi and A. Bicchi} } @conference {2398, title = {Electromyographic Mapping of Finger Stiffness in Tripod Grasp: a Proof of Concept}, booktitle = {International Conference on Rehabilitation Robotics (ICORR), 2015}, year = {2015}, note = {

softhands, wearhap

}, pages = {181-186}, publisher = {IEEE}, organization = {IEEE}, address = {Singapore, 11 {\textendash} 14 August 2015}, abstract = {

Effective execution of a manipulation task using prosthetic or robotic hands requires that the motion and the impedance profiles of the\ fingers\ be appropriately commanded. This, however, brings some design and control challenges regarding the individual planning and realization of the\ finger\ motion and\ stiffnesstrajectories. It appears that the central nervous system solves for this complexity in an effective and coordinated manner which has been well-recognized under the\ concept\ of hand synergies. While the exploitation of this\ concept\ in kinematic coordinates has lead to the development of several successful robotic designs and control strategies, its extension to dynamic coordinates, such as coordinated stiffening of the\ fingers, remains to be investigated. Indeed, in this study we provide preliminary evidence on the existence of such coordinated stiffening patterns in human\ fingers\ and establish initial steps towards a real-time and effective modelling of the\ fingerstiffness\ in a\ tripodgrasp. To achieve this goal, the endpoint\ stiffness\ of the thumb, index and middle\ fingers\ of five healthy subjects are experimentally identified and correlated with the electromyography (EMG) signals recorded from a dominant antagonistic pair of the forearm muscles. Our findings suggest that: i) the magnitude of thestiffness\ ellipses at the fingertips grows in a coordinated way, subsequent to the co-contraction of the forearm muscles; ii) the length of the ellipses{\textquoteright} axes appears to have a nearly linear relationship with the co-contraction level of the antagonistic muscle pair.

}, keywords = {Haptics, Robotics}, doi = {10.1109/ICORR.2015.7281196}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7281196}, author = {M. Rossi and Altobelli, A and S. B. Godfrey and A. Ajoudani and A. Bicchi} } @article {2207, title = {Epsilon{\textendash}optimal synthesis for vehicles with vertically bounded Field-Of-View}, journal = {IEEE Transactions on Automatic Control}, volume = {60}, year = {2015}, pages = {1204 - 1218}, abstract = {

This paper presents a contribution to the problem of obtaining an optimal synthesis for shortest paths for a unicycle guided by an on{\textendash}board limited Field Of{\textendash}View (FOV) sensor, which must keep a given landmark in sight. Previous works on this subject have provided an optimal synthesis for the case in which the FOV is limited in the horizontal directions (H{\textendash} FOV, i.e. left and right boundaries). In this paper we study the complementary case in which the FOV is limited only in the vertical direction (V{\textendash}FOV, i.e. upper and lower boundaries). With respect to the H{\textendash}FOV case, the vertical limitation is all but a simple extension. Indeed, not only the geometry of extremal arcs is different, but also a more complex structure of the synthesis is revealed by analysis. We will indeed show that there exist initial configurations for which the optimal path does not exist. In such cases, we provide an e{\textendash}optimal path whose length approximates arbitrarily well any other shorter path. Finally, we provide a partition of the motion plane in regions such that the optimal or e{\textendash}optimal path from each point in that region is univocally determined.

}, keywords = {Embedded Control, Robotics}, issn = {0018-9286}, doi = {10.1109/TAC.2014.2366271}, author = {Salaris, P. and Cristofaro, A. and L. Pallottino and A. Bicchi} } @conference {2539, title = {A Finite Element Model of Tactile Flow for Softness Perception}, booktitle = {37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC2015)}, year = {2015}, note = {

This work was partially supported by the European Research Council under the ERC Advanced Grant no. 291166 SoftHands (A Theory of Soft Synergies for a New Generation of Artificial Hands) and under the grant agreement no. 601165 Wearhap (Wearable Haptics for Humans and Robots), within the FP7/2007-2013 program: Cognitive Systems and Robotics.

}, pages = {2430 - 2433}, publisher = {IEEE}, organization = {IEEE}, address = {Milano, Italy, August 25th-29th, 2015}, keywords = {Haptics, Robotics}, doi = {10.1109/EMBC.2015.7318884}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7318884}, author = {E. Battaglia and M. Bianchi and M. L. D{\textquoteright}Angelo and M. D{\textquoteright}Imperio and F. Cannella and E. P. Scilingo and A. Bicchi} } @conference {2465, title = {Grasp Planning with Soft Hands using Bounding Box Object Decomposition}, booktitle = {IEEE International Conference of Intelligent Robots and Systems (IROS2015)}, year = {2015}, note = {

softhands pacman walkman

}, pages = {518 - 523}, publisher = {IEEE}, organization = {IEEE}, address = {Hamburg, Germany, September 28 - October 02, 2015}, keywords = {Haptics, Robotics}, doi = {10.1109/IROS.2015.7353421}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7353421\&queryText=Grasp\%20Planning\%20with\%20Soft\%20Hands\%20using\%20Bounding\%20Box\%20Object\%20Decomposition\&newsearch=true}, author = {M. Bonilla and D. Resasco and M Gabiccini and A. Bicchi} } @conference {2205, title = {Low-cost, Fast and Accurate Reconstruction of Robotic and Human Postures via IMU Measurements}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2015)}, year = {2015}, note = {

softhands wearhap

}, pages = {2728 - 2735}, publisher = {IEEE}, organization = {IEEE}, address = {Seattle, USA, 25 - 30 May}, keywords = {Robotics}, doi = {10.1109/ICRA.2015.7139569}, author = {G. Santaera and Luberto, E. and A. Serio and M Gabiccini and A. Bicchi} } @article {2540, title = {A muscle-like recruitment actuator with modular redundant actuation units for soft robotics}, journal = {Robotics and Autonomous Systems}, volume = {74}, year = {2015}, note = {

This work was supported by\ ERC-291166-SOFTHANDS

}, month = {12/2015}, pages = {40-50}, keywords = {Robotics}, doi = {10.1016/j.robot.2015.06.010}, url = {http://www.sciencedirect.com/science/article/pii/S0921889015001384}, author = {G. Mathijssen and J. Schultz and B. Vanderborght and A. Bicchi} } @conference {2453, title = {A Novel Tactile Display for Softness and Texture Rendering in Tele-Operation Tasks}, booktitle = { IEEE World Haptics Conference}, year = {2015}, note = {

This work is supported in part by the European Research Council under the Advanced Grant SoftHands {\textquotedblleft}A Theory of Soft Synergies for a New Generation of Artificial Hands{\textquotedblright} no. ERC-291166, and by the EU FP7 project (no. 601165), {\textquotedblleft}WEARable HAPtics for Humans and Robots (WEARHAP){\textquotedblright}

}, pages = {49-56}, publisher = {IEEE}, organization = {IEEE}, address = {Chicago, USA, 22-25 June 2015}, abstract = {

Softness\ and\ texture\ high-frequency information represent fundamental haptic properties for every day life activities and environment tactual exploration. While several\ displays\ have been produced to convey either\ softness\ or high-frequency information, there is no or little evidence of systems that are able to reproduce both these properties in an integrated fashion. This aspect is especially crucial in medical\ tele-operated procedures, where roughness and stiffness of human tissues are both important to correctly identify given pathologies through palpation (e.g. in\ tele-dermatology). This work presents a fabric yielding\ display\ (FYD-pad), a fabric-based\ tactiledisplay\ for\ softness\ and\ texturerendering. The system exploits the control of two motors to modify both the stretching state of the elastic fabric forsoftnessrendering\ and to convey\ texture\ information on the basis of accelerometer-based data. At the same time, the measurement of the contact area can be used to control remote or virtual robots. In this paper, we discuss the architecture of FYD-pad and the techniques used for\ softness\ and\ texturereproduction as well as for synthesizing probe-surface interactions from real data.\ Tele-operationexamples and preliminary experiments with humans are reported, which show the effectiveness of the device in delivering both\ softness\ and\ texture\ information.

}, keywords = {Haptics, Robotics}, doi = {10.1109/WHC.2015.7177690}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7177690}, author = {M. Bianchi and M. Poggiani and A. Serio and A. Bicchi} } @conference {2337, title = {Optimal Contact Force Distribution for Compliant Humanoid Robots in Whole-Body Loco-Manipulation Tasks}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2015)}, year = {2015}, pages = {5675 - 5681}, address = {Seattle, USA, 25 - 30 May}, keywords = {Haptics, Robotics}, doi = {10.1109/ICRA.2015.7139994}, author = {E. Farnioli and M Gabiccini and A. Bicchi} } @conference {2478, title = {Potential merits for space robotics from novel concepts of actuation for soft robotics}, booktitle = {Advanced Space Technologies for Robotics and Automation (ASTRA) }, year = {2015}, address = {Noordwijk, The Netherlands May 11-13, 2015}, keywords = {Robotics}, author = {G. Mathijssen and S. Terryn and R. Funemont and M. Garabini and M. G. Catalano and G. Grioli and D. Lefeber and A. Bicchi and B. Vanderborght} } @conference {2559, title = {A Reduced-Complexity Description of Arm Endpoint Stiffness with Applications to Teleimpedance Control}, booktitle = {IEEE International Conference of Intelligent Robots and Systems - IROS2015}, year = {2015}, note = {

softhands, wearhap

}, pages = {1017 - 1023}, publisher = {IEEE}, organization = {IEEE}, address = {Hamburg, Germany, 28 Sept - 2 Oct 2015}, abstract = {

Effective and stable execution of a remote task in an uncertain environment requires that the task force and position trajectories of the slave robot be appropriately commanded. To achieve this goal, in teleimpedance control, a reference command which consists of the stiffness and position profiles of the master is computed and realized by the compliant slave robot in real-time. This highlights the need for a suitable and computationally efficient tracking of the human limb stiffness profile in real-time. In this direction, based on the observations in human neuromotor control which give evidence on the predominant use of the arm configuration in directional adjustments of the endpoint stiffness profile, and the role of muscular co-activations which contribute to a coordinated stiffening of the task stiffness in all directions, we propose a novel and computationally efficient model of the arm endpoint stiffness behaviour. With the purpose of real-time tracking of the human arm kinematics, an arm triangle is introduced using three body markers at the shoulder, elbow and wrist joints. In addition, a co-contraction index is defined using muscular activities of a dominant antagonistic muscle pair. Calibration and identification of the model parameters are carried out experimentally, using perturbation-based arm endpoint stiffness measurements in different arm configurations and co-contraction levels of the chosen muscles. Results of this study suggest that the proposed model enables the master to naturally execute a remote task by modulating the direction of the major axes of the endpoint stiffness and its volume using arm configuration and the co-ativation of the involved muscles, respectively.

}, keywords = {Haptics, Robotics}, doi = {10.1109/IROS.2015.7353495}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7353495}, author = {A. Ajoudani and C. Fang and N G Tsagarakis and A. Bicchi} } @conference {2335, title = {On the Role of Robot Configuration in Cartesian Stiffness Control}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2015)}, year = {2015}, pages = {1010 - 1016}, address = {Seattle, USA, 25 - 30 May}, keywords = {Robotics}, doi = {10.1109/ICRA.2015.7139300}, author = {A. Ajoudani and N G Tsagarakis and A. Bicchi} } @conference {2338, title = {Sample-Based Motion Planning for Robot Manipulators with Closed Kinematic Chains}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2015)}, year = {2015}, note = {

softhands pacman walkman

}, pages = {2522 - 2527}, publisher = {IEEE}, organization = {IEEE}, address = {Seattle, USA, 25 - 30 May}, keywords = {Robotics}, doi = {10.1109/ICRA.2015.7139537}, author = {M. Bonilla and E. Farnioli and L. Pallottino and A. Bicchi} } @conference {2561, title = {A Selective Recruitment Strategy for Exploiting Muscle-Like Actuator Impedance Properties}, booktitle = {IEEE International Conference of Intelligent Robots and Systems - IROS2015}, year = {2015}, pages = {2231-2237}, publisher = {IEEE}, organization = {IEEE}, address = {Hamburg, Germany, 28 Sept - 2 Oct 2015}, abstract = {

Two leading qualities of skeletal muscle that produce good performance in uncertain environments are damage tolerance and the ability to modulate impedance. For this reason, robotics researchers are greatly interested in discovering the key characteristics of muscles that give them these properties and replicating them in actuators for robotic devices. This paper describes a method to harness the redundancy present in muscle-like actuation systems composed of multiple motor units and shows that they have these same two qualities. By carefully choosing which motor units are recruited, the impedance viewed from the environment can be modulated while maintaining the same overall activation level. The degree to which the impedance can be controlled varies with total activation level and actuator length.

Discretizing the actuation effort into multiple parts that work together, inspired by the way muscle fibers work in the human body, produces damage-tolerant behavior. This paper shows that this not only produces reasonably good resolutions without inordinate numbers of units, but gives the control system the ability to set the impedance along with the drive effort to the load.

}, keywords = {Robotics}, doi = {10.1109/IROS.2015.7353676}, author = {J. Shultz and G. Mathijssen and B. Vanderborght and A. Bicchi} } @article {1976, title = {Social Robotics and Societies of Robots}, journal = {The Information Society Special Issue: Beyond Industrial Robotics: Social Robots Entering Public and Domestic Spheres}, volume = {31}, year = {2015}, abstract = {

The sustainability of social robotics and other ambitious research programs

depends on the identification of lines of research that are coherent with its

visionary goals while satisfying more stringent constraints of feasibility and near-
term pay-offs. These multiple constraints are naturally conducive to the idea of a

society of robots operating within the physical environments of everyday human

life, developing there rich robot-robot social exchanges, and yet refraining from

any physical contact with human beings.

Achieving the visionary goals of social robotics or its more realistic objectives

requires extensive multidisciplinary cooperation. Accordingly, social robotics

may come to play a significant coordinating role for the constellation of research

communities in robotics. This coordinating role is exemplified here by reference

to a principled approach to robotic hand control based on sensory-motor soft

synergies: pursued in some current investigations on artificial hands, this

approach promises to meet distinctive needs arising in social robotics in the way

of dexterous manipulation of objects that are primarily conceived for human use.

}, keywords = {Robotics}, author = {A. Bicchi and G. Tamburrini} } @conference {2543, title = {Soft Actuation in Cyclic Motions: Stiffness Profile Optimization for Energy Efficiency}, booktitle = {15th IEEE RAS Humanoids Conference (HUMANOIDS2015)}, year = {2015}, note = {

saphari walkman

}, pages = {107 - 113}, publisher = {IEEE}, organization = {IEEE}, abstract = {
In this paper, we investigate the role of variable stiffness in the reduction of the energy cost for mechanical systems that perform desired tasks. The objective is to assess the use of Variable Stiffness Actuation (VSA) by determining an optimal stiffness profile and the associated energy cost of performing a desired task. For the analysis we consider mechanical systems of n-Degrees of Freedom (DoF), using VSA. We find an analytical solution that expresses the optimal stiffness profile during the task as a function of joint trajectories. This stiffness profile can be either constant or variable in time, and it minimizes a cost function, when performing a desired task.
We calculate the cost related to the torque of the system and the additional cost of changing or keeping a stiffness actively constant. Additionally, we discuss some cases for which it is worth to change the stiffness during a task and cases for which a constant stiffness may be better solution. Furthermore, from simulations and experiments we show cases in which using a variable stiffness profile allows cost savings w.r.t. constant
stiffness. The use of variable stiffness depends on the task, i.e. on the joint trajectories and their frequency, as well as on the mechanical implementation of the actuator used.
}, keywords = {Robotics}, doi = {10.1109/HUMANOIDS.2015.7363522}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7363522}, author = {A. Velasco and M. Garabini and M. G. Catalano and A. Bicchi} } @conference {2562, title = {Teaching by Demonstration on Dual-arm Robot using HRI Variable Stiffness Transferring}, booktitle = {IEEE International Conference on Robotics and Biomimetics - ROBIO2015}, year = {2015}, pages = {1202-1208}, publisher = {IEEE}, organization = {IEEE}, address = {Zhuhai, China, December 6-9, 2015}, keywords = {Robotics}, doi = {10.1109/ROBIO.2015.7418935}, url = {http://ieeexplore.ieee.org/document/7418935/}, author = {C. Yang and P. Liang and Z. Li and A. Ajoudani and C. Su and A. Bicchi} } @article {2158, title = {Tele- Impedance based Assistive Control for a Compliant Knee Exoskeleton: Stiffness Augmentation and Motion Assistance}, journal = {Robotics and Autonomous Systems}, volume = {73 part A}, year = {2015}, note = {

special issue\ "Wearable Robotics"

}, month = {11/2015}, pages = {78-90}, abstract = {

This paper presents a tele-impedance based assistive control scheme for a knee exoskeleton device. The proposed controller captures the user{\textquoteright}s intent to generate task-related assistive torques by means of the exoskeleton in different phases of the subject{\textquoteright}s normal activity. To do so, a detailed musculoskeletal model of the human knee is developed and experimentally calibrated to best match the user{\textquoteright}s kinematic and dynamic behavior. Three dominant antagonistic muscle pairs are used in our model, in which electromyography (EMG) signals are acquired, processed and used for the estimation of the knee joint torque, trajectory and the stiffness trend, in real time. The estimated stiffness trend is then scaled and mapped to a task-related stiffness interval to agree with the desired degree of assistance. The desired stiffness and equilibrium trajectories are then tracked by the exoskeleton{\textquoteright}s impedance controller. As a consequence, while minimum muscular activity corresponds to low stiffness, i.e.\ highly transparent motion, higher co-contractions result in a stiffer joint and a greater level of assistance. To evaluate the robustness of the proposed technique, a study of the dynamics of the human{\textendash}exoskeleton system is conducted, while the stability in the steady state and transient condition is investigated. In addition, experimental results of standing-up and sitting-down tasks are demonstrated to further investigate the capabilities of the controller. The results indicate that the compliant knee exoskeleton, incorporating the proposed tele-impedance controller, can effectively generate assistive actions that are volitionally and intuitively controlled by the user{\textquoteright}s muscle activity.

}, keywords = {Robotics}, doi = {10.1016/j.robot.2014.09.027}, url = {http://www.sciencedirect.com/science/article/pii/S0921889014002127}, author = {N. Karavas and A. Ajoudani and N G Tsagarakis and J. Saglia and A. Bicchi and D. Caldwell} } @article {2080, title = {Variable Stiffness Actuators: the user{\textquoteright}s point of view}, journal = {Int. J. Robotics Research}, volume = {34}, year = {2015}, note = {

Extensions.zip

}, month = {05/2015}, pages = {727-743}, keywords = {Robotics}, doi = {10.1177/0278364914566515}, url = {http://ijr.sagepub.com/cgi/reprint/0278364914566515v1.pdf?ijkey=anmgudvoLz7ZloP\&keytype=finite}, author = {G. Grioli and S. Wolf and M. Garabini and M. G. Catalano and E. Burdet and D. G. Caldwell and R. Carloni and W. Friedl and M. Grebenstein and M. Laffranchi and D. Lefeber and S. Stramigioli and N G Tsagarakis and M. Van Damme and B. Vanderborght and A Albu-Schaeffer and A. Bicchi} } @conference {2450, title = {Variable Stiffness Control for Oscillation Damping}, booktitle = {IEEE International Conference of Intelligent Robots and Systems (IROS2015)}, year = {2015}, note = {
This work is supported by the EC under the grant agreements no.611832 Walk-Man and ICT-287513 {\textquotedblleft}SAPHARI{\textquotedblright}
}, pages = {6543 - 6550}, publisher = {IEEE}, organization = {IEEE}, address = {Hamburg, Germany, September 28 - October 02, 2015}, keywords = {Robotics}, doi = {10.1109/IROS.2015.7354312}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7354312}, author = {G M Gasparri and M. Garabini and L. Pallottino and L. Malagia and M. G. Catalano and G. Grioli and A. Bicchi} } @conference {2121, title = {Active gathering of frictional properties from objects}, booktitle = {Proc. IEEE/RSJ Intl Conf. on Intelligent Robots and Systems (IROS 2014)}, year = {2014}, pages = {3982 - 3987 }, publisher = {IEEE}, organization = {IEEE}, address = {Chicago, USA}, keywords = {Haptics, Robotics}, doi = {10.1109/IROS.2014.6943122}, author = {C. Rosales and A. Ajoudani and M Gabiccini and A. Bicchi} } @article {1665, title = {Adaptive Synergies for the Design and Control of the Pisa/IIT SoftHand}, journal = {International Journal of Robotics Research}, volume = {33}, year = {2014}, pages = {768{\textendash}782}, keywords = {Haptics, Robotics}, doi = {10.1177/0278364913518998}, author = {M. G. Catalano and G. Grioli and E. Farnioli and A. Serio and C. Piazza and A. Bicchi} } @article {1445, title = {Biomechanisch sichere Geschwindigkeitsregelung fur die Mensch-Roboter Interaktion}, journal = {At-Automatisierungstechnik }, volume = {62}, year = {2014}, pages = {175 - 187}, keywords = {Robotics}, issn = {0178-2312}, author = {S. Haddadin and S. Haddadin and A. Khoury and T. Rokahr and S. Parusel and R. Burgkart and A. Bicchi and A Albu-Schaeffer} } @conference {2086, title = {A change in the fingertip contact area induces an illusory displacement of the finger}, booktitle = {Eurohaptics}, volume = {LNCS - Free Preview Haptics: Neuroscience, Devices, Modeling, and Applications}, year = {2014}, pages = {72 - 79}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Versailles, France), June 2014}, keywords = {Haptics, Robotics}, doi = {10.1007/978-3-662-44196-1_10}, author = {A. Moscatelli and M. Bianchi and A. Serio and Al Atassi, O. and S. Fani and A. Terekhov and V. Hayward and M. Ernst and A. Bicchi} } @conference {2082, title = {Design and preliminary affective characterization of a novel fabric-based tactile display}, booktitle = {Haptics Symposium (HAPTICS), 2014 IEEE}, year = {2014}, pages = { 591 - 596}, address = {Houston, TX}, keywords = {Haptics, Robotics}, doi = {10.1109/HAPTICS.2014.6775522}, author = {M. Bianchi and G. Valenza and A. Serio and A Lanata and L. Greco and M. Nardelli and E. P. Scilingo and A. Bicchi} } @conference {2113, title = {Drum Stroke Variation Using Variable Stiffness Actuators}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2014)}, year = {2014}, pages = {3892 - 3897 }, publisher = {IEEE}, organization = {IEEE}, address = {Chicago, IL, USA}, abstract = {

One interesting field of robotics technology is related to the entertainment industry. Performing a musical piece using a robot is a difficult task because music presents many features like melody, rhythm, tone, harmony and so on. Addressing these tasks with a robot is not trivial to implement. Most of approaches which related to this specific field lacks of quality to perform in front of human audience. Implementation of human-like motions can not be properly achieved with a conventional robot actuator. Consequently, we exploit a new type of actuator which simplifies the drawbacks of a conventional one. We used Variable Stiffness Actuator(VSA) instead of using conventional actuator. We can control position, force, and stiffness, simultaneously by using VSA. The most important novel feature is its controllable stiffness. When the stiffness of the actuator is changed, the characteristics of the actuator{\textquoteright}s response also changes. We implemented the specific stroke which is called {\textquotedblleft}double stroke{\textquotedblright} using one of variable stiffness actuator. Although the double stroke is known as a special stroke which could be performed by human only, double stroke is successfully implemented by stiffness variation.

}, keywords = {Robotics}, doi = {10.1109/IROS.2014.6943109}, author = {Y. Kim and M. Garabini and J. Park and A. Bicchi} } @conference {2233, title = {Exploiting hand kinematic synergies and wearable under-sensing for hand functional grasp recognition}, booktitle = { 4th International Conference on Wireless Mobile Communication and Healthcare - "Transforming healthcare through innovations in mobile and wireless technologies" }, year = {2014}, address = {November 3{\textendash}5, 2014 Athens, Greece}, keywords = {Haptics, Robotics}, doi = { http://dx.doi.org/10.4108/icst.mobihealth.2014.257228}, author = {M. Bianchi and N. Carbonaro and E. Battaglia and F. Lorussi and A. Bicchi and D. De Rossi and A. Tognetti} } @conference {2081, title = {Exploring haptic feedback for the Pisa/IIT SoftHand}, booktitle = {Haptics Symposium (HAPTICS), 2014 IEEE}, year = {2014}, address = {Houston, TX}, keywords = {Haptics, Robotics}, doi = {10.1109/HAPTICS.2014.6775572}, author = {S. B. Godfrey and A. Ajoudani and M. Bianchi and M. G. Catalano and G. Grioli and A. Bicchi} } @article {1668, title = {Exploring Teleimpedance and Tactile Feedback for Intuitive Control of the Pisa/IIT SoftHand}, journal = { IEEE Transactions on Haptics}, volume = {7}, year = {2014}, pages = {203 - 215}, keywords = {Haptics, Robotics}, doi = {10.1109/TOH.2014.2309142 }, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6755554}, author = {A. Ajoudani and S. B. Godfrey and M. G. Catalano and M. Bianchi and G. Grioli and N G Tsagarakis and A. Bicchi} } @inbook {2087, title = {A Fabric-based Approach for Softness Rendering}, booktitle = {Multisensory Softness: Perceived Compliance from Multiple Sources of Information}, volume = {Springer Series on Touch and Haptic Systems}, year = {2014}, pages = {219 - 240}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, chapter = {11}, abstract = {

In this chapter we describe a softness display based on the contact area spread rate (CASR) paradigm. This device uses a stretchable fabric as a substrate that can be touched by users, while contact area is directly measured via an optical system. By varying the stretching state of the fabric, different stiffness values can be conveyed to users. We describe a first technological implementation of the display and compare its performance in rendering various levels of stiffness with the one exhibited by a pneumatic CASR-based device. Psychophysical experiments are reported and discussed. Afterwards, we present a new technological implementation for the fabric-based display, with reduced dimensions and faster actuation, which enables rapid changes in the fabric stretching state. These changes are mandatory to properly track typical force/area curves of real materials. System performance in mimicking force-area curves obtained from real objects exhibits a high degree of reliability, also in eliciting overall discriminable levels of softness.

}, keywords = {Haptics, Robotics}, issn = {978-1-4471-6532-3}, doi = {10.1007/978-1-4471-6533-0_11}, url = {http://link.springer.com/chapter/10.1007\%2F978-1-4471-6533-0_11}, author = {M. Bianchi and A. Serio and E. P. Scilingo and A. Bicchi} } @conference {2232, title = {Grasping with Soft Hands}, booktitle = {IEEE-RAS International Conference on Humanoid Robots (HUMANOIDS 2014)}, year = {2014}, pages = {581 - 587}, address = {Madrid, Spain, November 18 - 20}, abstract = {

Despite some prematurely optimistic claims, the ability of robots to grasp general objects in unstructured environments still remains far behind that of humans. This is not solely caused by differences in the mechanics of hands: indeed, we show that human use of a simple robot hand (the Pisa/IIT SoftHand) can afford capabilities that are comparable to natural grasping. It is through the observation of such human-directed robot hand operations that we realized how fundamental in everyday grasping and manipulation is the role of hand compliance, which is used to adapt to the shape of surrounding objects. Objects and environmental constraints are in turn used to functionally shape the hand, going beyond its nominal kinematic limits by exploiting structural softness. In this paper, we set out to study grasp planning for hands that are simple {\textemdash} in the sense of low number of actuated degrees of freedom (one for the Pisa/IIT SoftHand) {\textemdash} but are soft, i.e. continuously deformable in an infinity of possible shapes through interaction with objects. After general considerations on the change of paradigm in grasp planning that this setting brings about with respect to classical rigid multi-dof grasp planning, we present a procedure to extract grasp affordances for the Pisa/IIT SoftHand through physically accurate numerical simulations. The selected grasps are then successfully tested in an experimental scenario.

}, keywords = {Haptics, Robotics}, doi = {10.1109/HUMANOIDS.2014.7041421}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=\&arnumber=7041421\&queryText\%3DGrasping+with+Soft+Hands}, author = {M. Bonilla and E. Farnioli and C. Piazza and M. G. Catalano and G. Grioli and M. Garabini and M Gabiccini and A. Bicchi} } @inbook {1694, title = {HANDS.DVI: A DeVice-Independent programming and control framework for robotic HANDS}, booktitle = {Gearing up and accelerating cross-fertilization between academic and industrial robotics research in Europe - Technology transfer experiments from the ECHORD project}, volume = {94}, number = {Springer Tracts in Advanced Robotics}, year = {2014}, pages = {197-215}, abstract = {

The scientific goal of HANDS.DVI consists of developing a common
framework to programming robotic hands independently from their kinematics,
mechanical construction, and sensor equipment complexity. Recent results on the
organization of the human hand in grasping and manipulation are the inspiration
for this experiment. The reduced set of parameters that we effectively use to control
our hands is known in the literature as the set of synergies. The synergistic
organization of the human hand is the theoretical foundation of the innovative approach
to design a unified framework for robotic hands control. Theoretical tools
have been studied to design a suitable mapping function of the control action (decomposed
in its elemental action) from a human hand model domain onto the
articulated robotic hand co-domain. The developed control framework has been
applied on an experimental set up consisting of two robotic hands with dissimilar
kinematics grasping an object instrumented with force sensors.

}, keywords = {Haptics, Robotics}, doi = {10.1007/978-3-319-02934-4_10}, author = {G. Salvietti and G. Gioioso and M. Malvezzi and D Prattichizzo and A. Serio and E. Farnioli and M Gabiccini and A. Bicchi and I. Sarakoglou and N G Tsagarakis and D. G. Caldwell} } @conference {2119, title = {Haptic Exploration of Unknown Surfaces with Discontinuities}, booktitle = {Proc. IEEE/RSJ Intl Conf. on Intelligent Robots and Systems (IROS 2014)}, year = {2014}, month = {09/2014}, pages = {1255 - 1260}, address = {Chicago, USA}, keywords = {Haptics, Robotics}, doi = {10.1109/IROS.2014.6942718}, url = {http://kormushev.com/papers/Jamisola_IROS-2014.pdf}, author = {Jamisola, R. S. and Kormushev, P. and A. Bicchi and D. G. Caldwell} } @conference {2159, title = {Manipulation Framework for Compliant Humanoid COMAN: Application to a Valve Turning Task}, booktitle = {IEEE-RAS International Conference on Humanoid Robots (HUMANOIDS 2014)}, year = {2014}, pages = {664 - 670}, publisher = {IEEE}, organization = {IEEE}, address = {Madrid, Spain, November 18 - 20}, abstract = {

With the purpose of achieving a desired interaction performance for our compliant humanoid robot (COMAN), in this paper we propose a semi-autonomous control framework and evaluate it experimentally in a valve turning setup. The control structure consists of various modules and interfaces to identify the valve, locate the robot in front of it and perform the manipulation. The manipulation module implements four motion primitives (Reach, Grasp, Rotate and Disengage) and realizes the corresponding desired impedance profile for each phase to accomplish the task. In this direction, to establish a stable and compliant contact between the valve and the robot hands, while being able to generate the sufficient rotational torques depending on the valve{\textquoteright}s friction, Rotate incorporates a novel dual-arm impedance control technique to plan and realize a task-appropriate impedance profile. Results of the implementation of the proposed control framework are firstly evaluated in simulation studies using Gazebo. Subsequent experimental results highlight the efficiency of the proposed impedance planning and control in generation of the required interaction forces to accomplish the task.

}, keywords = {Haptics, Robotics}, doi = {10.1109/HUMANOIDS.2014.7041434}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7041434}, author = {A. Ajoudani and J. Lee and A. Rocchi and M. Ferrati and E. Mingo Hoffman and A Settimi and D. G. Caldwell and A. Bicchi and N G Tsagarakis} } @conference {2127, title = {A modular approach for remote operation of humanoid robots in search and rescue scenarios }, booktitle = {Modelling \& Simulation for Autonomous Systems - MESAS2014}, year = {2014}, address = {Rome, 5-6 May 2014}, keywords = {Robotics}, author = {A Settimi and C. Pavan and V. Varricchio and M. Ferrati and E. Mingo and A. Rocchi and K. Melo and N G Tsagarakis and A. Bicchi} } @conference {1983, title = {Natural Redundancy Resolution in Dual-Arm Manipulation using Configuration Dependent Stiffness (CDS) Control}, booktitle = {2014 IEEE International Conference on Robotics and Automation}, year = {2014}, pages = {1480 - 1486}, publisher = {IEEE}, organization = {IEEE}, address = {Hong Kong, May 31 2014-June 7 2014 }, abstract = {

Incorporation of human motor control principles in the motion control architectures for humanoid robots or assistive and prosthesis devices will permit these systems not only to look anthropomorphic and natural at the body ware level but also to generate natural motion profiles resembling those executed by humans during manipulation and locomotion. In this work, relying on the observations on human bimanual coordination, a novel realtime motion control strategy is proposed to regulate the desired Cartesian stiffness profile during the execution of bimanual tasks. The novelty of the proposed control scheme relies on the use of common mode stiffness (CMS) and configuration dependent stiffness (CDS) to regulate the size and directionality of the task space stiffness ellipsoid. Thanks to the CDS control, the proposed scheme is not only proved to be effective in regulating the desired stiffness ellipsoid but also permits to resolve the manipulator redundancy in a natural manner. The effectiveness of the controller is evaluated in an experimental setup in which two cooperating robotic arms are executing an assembly task. Experimental results demonstrate that the proposed dual-arm CDS-CMS controller is effective in tracking the desired stiffness ellipsoids as well as in producing human-like natural motions for the two robotic arms.

}, keywords = {Haptics, Robotics}, doi = {10.1109/ICRA.2014.6907047}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6945252}, author = {A. Ajoudani and N G Tsagarakis and J. Lee and M Gabiccini and A. Bicchi} } @conference {2151, title = {Open Source VSA-CubeBots for Rapid Soft Robot Prototyping }, booktitle = { Robot Makers - Workshop in conjunction with 2014 Robotics Science and Systems}, year = {2014}, address = { July 12, 2014, Berkeley, California }, keywords = {Robotics}, author = {K. Melo and M. Garabini and G. Grioli and M. G. Catalano and L. Malagia and A. Bicchi} } @conference {2120, title = {The Patched Intrinsic Tactile Object: a Tool to Investigate Human Grasps}, booktitle = {Proc. IEEE/RSJ Intl Conf. on Intelligent Robots and Systems (IROS 2014)}, year = {2014}, pages = {1261 - 1268}, address = {Chicago, USA}, abstract = {

In this paper we report on the development of a modular multi-DoF F/T sensor and its use in the implementation of a sensorized object capable of multi-touch detection. The sensor is composed of six 6-axis F/T sensors spatially organized on the faces of a cube. Different calibration methods are presented to directly tackle the coupling phenomena inherent to the spatial organization of the faces and the lightweight construction of the sensor which would have, otherwise, degraded its accuracy. To assess the performances of the calibration methods, a comparison is reported with respect to the measurements obtained with a commercial force/torque sensor considered as ground truth (ATI Delta). Thanks to the modular design and the possibility to cover the sensitive faces with surface patches of different geometry, a variety of sensorized objects with different shapes can be realized. The peculiar feature that all the components of the contact wrench can be measured on each face with high accuracy, renders it a unique tool in the study of grasp force distribution in humans, with envisioned use both in neuroscience investigations and robotic applications.

}, keywords = {Haptics, Robotics}, doi = {10.1109/IROS.2014.6942719}, author = {A. Serio and E. Riccomini and V. Tartaglia and I. Sarakoglou and M Gabiccini and N G Tsagarakis and A. Bicchi} } @article {2153, title = {Peripheral Machine Interfaces: going beyond traditional surface electromyography}, journal = {Frontiers in Neurorobotics}, volume = {8}, year = {2014}, month = {08/2014}, pages = {1 - 17}, keywords = {Robotics}, doi = {10.3389/fnbot.2014.00022}, author = {C. Castellini and P. Artemiadis and M. Wininger and A. Ajoudani and M. Alimusaj and A. Bicchi and B. Caputo and W. Craelius and S. Dosen and K. Englehart and D. Farina and A. Gijsberts and S. B. Godfrey and L. Hargrove and M. Ison and T. Kuiken and M. Markovic and P. M. Pilarski and R. Rupp and E. Scheme} } @article {2234, title = {Special Issue on the Mechanics and Design of Robotic Hands}, year = {2014}, keywords = {Haptics, Robotics}, author = {Dollar, A. and A. Bicchi and M. Cutkosky and Howe, D.} } @article {1986, title = {A Stiffness Estimator for Agonistic{\textendash}Antagonistic Variable-Stiffness-Actuator Devices}, journal = { IEEE Transactions on Robotics}, volume = {30}, year = {2014}, pages = {1269 - 1278 }, abstract = {

Safe physical human-robot interaction, conservation of energy, and adaptability are the main robotic applications that prompted the development of a number of variable stiffness actuators (VSAs). Implemented in a variety of ways, they use various technologies and feature the most diverse mechanical solutions, all of which share a fundamentally unavoidable nonlinear behavior. The control schemes proposed for these actuators typically aim at independent control of the position of the link and its stiffness. Although effective feedback control schemes using position and force sensors are commonplace in robotics, control of stiffness is at present completely open loop: The stiffness is inferred from the mathematical model of the actuator. We consider here the problem of estimating the nonlinear stiffness of VSA in agonistic-antagonistic configuration. We propose an algorithm based on modulating functions that allow us to avoid the need for numerical derivative and for which the tuning is then very simple. An analysis of the error demonstrates the convergence. Simulations are provided, and the algorithm is validated on experimental data.

}, keywords = {Robotics}, issn = {1552-3098}, doi = {10.1109/TRO.2014.2329998}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=\&arnumber=6860244\&queryText\%3DA+stiffness+estimator+for+AA-VSA+devices}, author = {T. Menard and G. Grioli and A. Bicchi} } @conference {2084, title = {The tactile toolbox}, booktitle = {Haptics Symposium (HAPTICS), 2014 IEEE}, year = {2014}, address = {Houston, TX}, keywords = {Haptics, Robotics}, doi = {10.1109/HAPTICS.2014.6775573}, author = {A. Serio and M. Bianchi and M Gabiccini and A. Bicchi} } @conference {2083, title = {ThimbleSense: A new wearable tactile device for human and robotic fingers }, booktitle = {Haptics Symposium (HAPTICS), 2014 IEEE}, year = {2014}, address = {Houston, TX}, keywords = {Haptics, Robotics}, doi = {10.1109/HAPTICS.2014.6775571}, author = {E. Battaglia and G. Grioli and M. G. Catalano and M. Bianchi and A. Serio and M. Santello and A. Bicchi} } @conference {2130, title = {ThimbleSense: An Individual-Digit Wearable Tactile Sensor for Experimental Grasp Studies}, booktitle = {IEEE International Conference on Robotics and Automation - ICRA 2014}, year = {2014}, pages = {2728 - 2735 }, publisher = {IEEE}, organization = {IEEE}, address = { Hong Kong, May 31 - June 7, 2014}, abstract = {

Measuring contact forces applied by a hand to a grasped object is a necessary step to understand the mysteries that still hide in the unparalleled human grasping ability. Nevertheless, simultaneous collection of information about the position of contacts and about the magnitude and direction of forces is still an elusive task. In this paper we introduce a wearable device that addresses this problem, and can be used to measure generalized forces during grasping. By assembling two supports around a commercial 6-axis force/torque sensor we obtain a thimble that can be easily positioned on a fingertip. The device is used in conjunction with an active marker-based motion capture system to simultaneously obtain absolute position and orientation of the thimbles, without requiring any assumptions on the kinematics of the hand. Finally, using the contact centroid algorithm, introduced in [1], position of contact points during grasping are determined. This paper shows the design and implementation of the device, as well as some preliminary experimental validation.

}, keywords = {Haptics, Robotics}, doi = {10.1109/ICRA.2014.6907250 }, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6907250}, author = {E. Battaglia and G. Grioli and M. G. Catalano and M. Santello and A. Bicchi} } @conference {2307, title = { Three-digit grasp haptic device with variable contact stiffness for rehabilitation and human grasping studies}, booktitle = {22nd Mediterranean Conference of Control and Automation (MED) 2014 }, year = {2014}, pages = {346 - 350}, publisher = {IEEE}, organization = {IEEE}, address = {Palermo, Italy, 16-19 June 2014 }, abstract = {

This paper describes an haptic system designed to vary the stiffness of three contact points in an independent and controllable fashion, by suitably regulating the inner pressure of three pneumatic tactile displays. At the same time, the contact forces exerted by the user are measured by six degree-of-freedom force sensors placed under each finger. This device might be profitably used in hand rehabilitation and human grasping studies. We report and discuss preliminary results on device validation as well as some illustrative measurement examples.

}, keywords = {Haptics, Robotics}, doi = {10.1109/MED.2014.6961395}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6961395}, author = {Altobelli, A and M. Bianchi and A. Serio and Baud-Bovy, G and M Gabiccini and A. Bicchi} } @conference {2223, title = {On Time-Optimal Trajectories for Differential Drive Vehicles with Field-Of-View Constraints}, booktitle = {IEEE Conference on Decision and Control (CDC2014)}, year = {2014}, pages = {2191 - 2197}, publisher = {IEEE}, organization = {IEEE}, address = {Los Angeles, USA, December 15-17}, abstract = {

This paper presents the first step toward the study of minimum time trajectories for a differential drive robot, which is equipped with a fixed and limited Field-Of-View (FOV) camera, towards a desired configuration while keeping a given landmark in sight during maneuvers. While several previous works have provided a complete synthesis of shortest paths in case of both nonholonomic and FOV constraints, to the best of our knowledge, this paper represents the first analysis of minimum time trajectories with the two constraints. After showing the extremals of the problem at hand, i.e. straight lines, rotations on the spot, logarithmic spirals and involute of circles, we provide the optimal control laws that steer the vehicle along the path and the cost in terms of time along each extremal. Moreover, we compare some concatenations of extremals in order to reduce the complexity of the problem toward the definition of a sufficient finite set of optimal maneuvers.

}, keywords = {Embedded Control, Robotics}, isbn = {978-1-4799-7746-8}, doi = {10.1109/CDC.2014.7039723}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7039723}, author = {Cristofaro, A. and Salaris, P. and L. Pallottino and Giannoni, F. and A. Bicchi} } @conference {2160, title = {Upper-body Impedance Control with an Intuitive Stiffness Emulation for a Door Opening Task}, booktitle = {IEEE-RAS International Conference on Humanoid Robots (HUMANOIDS 2014)}, year = {2014}, pages = {713 - 719}, publisher = {IEEE}, organization = {IEEE}, address = {Madrid, Spain, November 18 - 20}, abstract = {

The advent of humanoids has brought new challenges in the real-world application. As a part of ongoing efforts to foster functionality of the robot accommodating a real environment, this paper introduces a recent progress on a door opening task with our compliant humanoid, CoMan. We presents a task-prioritized impedance control framework for an upper body system that includes a dual-arm, a waist, two soft hands, and 3D camera. Aimed to create desired responses to open the door, a novel stiffness modulation method is proposed, incorporating a realtime optimization. As a preliminary experiment, a full door-opening scenario (approaching to the door and reaching, grasping, rotating and pulling the door handle) is demonstrated under a semi-autonomous operation with a pilot. The experimental result shows the effectiveness and efficacy of the proposed impedance control approach. Despite of uncertainties from sensory data, the door opening task is successfully achieved and safe and robust interaction is established without creating excessive forces.

}, keywords = {Robotics}, doi = {10.1109/HUMANOIDS.2014.7041441}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=7041441}, author = {J. Lee and A. Ajoudani and E. Mingo Hoffman and A. Rocchi and A Settimi and M. Ferrati and A. Bicchi and N G Tsagarakis and D. G. Caldwell} } @conference {2037, title = {Velvet Fingers: Grasp Planning and Execution for an Underactuated Gripper with Active Surfaces}, booktitle = {2014 IEEE International Conference on Robotics and Automation}, year = {2014}, pages = {3669 - 3675}, publisher = {IEEE}, organization = {IEEE}, address = {Hong Kong, May 31 2014-June 7 2014}, abstract = {

In this work we tackle the problem of planning grasps for an underactuated gripper which enable it to retrieve target objects from a cluttered environment. Furthermore, we investigate how additional manipulation capabilities of the gripping device, provided by active surfaces on the inside of the fingers, can lead to performance improvement in the grasp execution process. To this end, we employ a simple strategy, in which the target object is {\textquoteleft}pulled-in{\textquoteright} towards the palm during grasping which results in firm enveloping grasps. We show the effectiveness of the suggested methods by means of experiments conducted in a real-world scenario.

}, keywords = {Haptics, Robotics}, doi = {10.1109/ICRA.2014.6907390 }, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6907390}, author = {R. Krug and T. Stoyanov and M. Bonilla and V. Tincani and N. Vaskeviciusz and G Fantoni and A. Birkz and A. Lilienthal and A. Bicchi} } @conference {2077, title = {Yarp Based Plugins for Gazebo Simulator}, booktitle = {2014 Modelling and Simulation for Autonomous Systems Workshop (MESAS)}, year = {2014}, address = {Roma, Italy, 5 -6 May 2014}, keywords = {Robotics}, author = {Mingo, E and Traversaro, S and Rocchi, A and M. Ferrati and A Settimi and Romano, F and Natale, L and A. Bicchi and Nori, F and N G Tsagarakis} } @article {1725, title = {A Complete Observability Analysis of the Planar Bearing Localization and Mapping for Visual Servoing with Known Camera Velocities}, journal = {International Journal of Advanced Robotic Systems}, volume = {10}, year = {2013}, abstract = {

This paper presents an analysis of planar bearing localization and mapping for visual servoing with known camera velocities. In particular, we investigate what is the subset of camera locations and environmental features that can be retrieved from dynamic observations obtained by a planar bearing sensor (nearly e.g., a pinhole camera). Results assume that the camera{\textquoteright}s linear and angular velocities are available, which is equivalent to consider a unicycle vehicle carrying an onboard camera. Results hold if other system inputs are considered, e.g., an omnidirectional vehicle. The theoretical results may guide the design of nonlinear observers to estimate the variables of interest in real time to be applied to visual servoing schemes. An example of such an observer is discussed and simulated.

}, keywords = {Robotics}, doi = {10.5772/54603}, url = {http://www.intechopen.com/books/international_journal_of_advanced_robotic_systems/a-complete-observability-analysis-of-the-planar-bearing-localization-and-mapping-for-visual-servoing}, author = {F. A. W. Belo and P Salaris and D. Fontanelli and A. Bicchi} } @conference {1667, title = {Controlling the active surfaces of the Velvet Fingers: sticky to slippy fingers}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2013}, year = {2013}, month = {November 3-7}, pages = {5494 - 5499}, address = {Tokyo, Japan}, abstract = {

Industrial grippers are often used for grasping, while in-hand re-orientation and positioning are dealt with by other means. Contact surface engineering has been recently proposed as a possible mean to introduce dexterity in simple grippers, as in the Velvet Fingers smart gripper, a novel concept of end-effector combining simple under-actuated mechanics and high manipulation possibilities, thanks to conveyors which are built in the finger pads. This paper undergoes the modeling and control of the active conveyors of the Velvet Fingers gripper which are rendered able to emulate different levels of friction and to apply tangential thrusts to the contacted objects. Through the paper particular attention is dedicated to the mechanical implementation, sense drive and control electronics of the device. The capabilities of the prototype are showed in some grasping and manipulation experiments.

}, keywords = {Robotics}, doi = {10.1109/IROS.2013.6697152}, url = {http://ieeexplore.ieee.org/xpl/login.jsp?tp=\&arnumber=6697152\&url=http\%3A\%2F\%2Fieeexplore.ieee.org\%2Fxpls\%2Fabs_all.jsp\%3Farnumber\%3D6697152}, author = {V. Tincani and G. Grioli and M. G. Catalano and M. Bonilla and M. Garabini and G Fantoni and A. Bicchi} } @conference {1705, title = {A Device for Mimicking the Contact Force/Contact Area Relationship of Different Materials with Applications to Softness Rendering}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2013}, year = {2013}, month = {November 3-7}, pages = {4484 - 4490 }, address = {Tokyo, Japan}, keywords = {Robotics}, doi = {10.1109/IROS.2013.6697001 }, author = {A. Serio and M. Bianchi and A. Bicchi} } @article {1821, title = {Grasp Analysis Tools for Synergistic Underactuated Robotic Hands}, journal = {International Journal of Robotic Reasearch}, volume = {32}, year = {2013}, month = {11/2013}, pages = {1553 - 1576}, keywords = {Haptics, Robotics}, author = {M Gabiccini and E. Farnioli and A. Bicchi} } @conference {1706, title = {Grasp Compliance Regulation in Synergistically Controlled Robotic Hands with VSA}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2013}, year = {2013}, month = {November 3-7}, pages = {3015 -3022}, address = {Tokyo, Japan}, keywords = {Robotics}, doi = {10.1109/IROS.2013.6696783 }, author = {E. Farnioli and M Gabiccini and M. Bonilla and A. Bicchi} } @conference {1434, title = {Human-Like Impedance and Minimum Effort Control for Natural and Efficient Manipulation}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2013)}, year = {2013}, pages = {4499 - 4505}, keywords = {Robotics}, doi = {10.1109/ICRA.2013.6631216 }, author = {A. Ajoudani and M Gabiccini and N G Tsagarakis and A. Bicchi} } @conference {1438, title = {Implementation and Control of the Velvet Fingers: a Dexterous Gripper with Active Surfaces}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2013)}, year = {2013}, pages = {2744 - 2750}, keywords = {Haptics, Robotics}, url = {10.1109/ICRA.2013.6630955 }, author = {V. Tincani and G. Grioli and M. G. Catalano and M. Garabini and S. Grechi and G Fantoni and A. Bicchi} } @article {1683, title = {On Motion and Force Controllability of Precision Grasps with Hands Actuated by Soft Synergies}, journal = {IEEE Transactions on Robotics}, volume = {29}, year = {2013}, month = {12/2013}, pages = {1440 - 1456 }, abstract = {

To adapt to many different objects and tasks, hands are very complex systems with many degrees of freedom (DoFs), sensors, and actuators. In robotics, such complexity comes at the cost of size and weight of the hardware of devices, but it strongly affects also the ease of their programming. A possible approach to simplification consists in coupling some of the DOFs, thus affording a reduction of the number of effective inputs, and eventually leading to more efficient, simpler, and reliable designs. Such coupling can be at the software level, to achieve faster, more intuitive programmability or at the hardware level, through either rigid or compliant physical couplings between joints. Physical coupling between actuators and simplification of control through the reduction of independent inputs is also an often-reported interpretation of human hand movement data, where studies have demonstrated that few {\textquotedblleft}postural synergies{\textquotedblright} explain most of the variance in hand configurations used to grasp different objects. Together with beneficial simplifications, the reduction of the number of independent inputs to a few coupled motions or {\textquotedblleft}synergies{\textquotedblright} has also an impact on the ability of the hand to dexterously control grasp forces and in-hand manipulation. This paper aims to develop tools that establish how many synergies should be involved in a grasp to guarantee stability and efficiency, depending on the task and on the hand embodiment. Through the analysis of a quasi-static model, grasp structural properties related to contact force and object motion controllability are defined. Different compliant sources are considered, for a generalization of the discussion. In particular, a compliant model for synergies assumed, referred to as {\textquotedblleft}soft synergies,{\textquotedblright} is discussed. The controllable internal forces and motions of the grasped object are related to the actuated inputs. This paper investigates to what extent a hand with many joints can ex- loit postural synergies to control force and motion of the grasped object.

}, keywords = {Haptics, Robotics}, doi = {10.1109/TRO.2013.2273849}, author = {D Prattichizzo and M. Malvezzi and M Gabiccini and A. Bicchi} } @conference {1437, title = {Optimal Control and Design Guidelines for Soft Jumping Robots: Series Elastic Actuation and Parallel Elastic Actuation in comparison}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2013)}, year = {2013}, pages = {2477 - 2484}, keywords = {Robotics}, url = {10.1109/ICRA.2013.6630914 }, author = {R. Incaini and L. Sestini and M. Garabini and M. G. Catalano and G. Grioli and A. Bicchi} } @conference {1447, title = {Optimal Control for Maximizing Velocity of the CompActTM Compliant Actuator}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2013)}, year = {2013}, pages = {516 - 522}, keywords = {Robotics}, url = {10.1109/ICRA.2013.6630623}, author = {L. Chen and M. Garabini and M. Laffranchi and N. Kashiri and N G Tsagarakis and A. Bicchi and D. G. Caldwell} } @conference {1583, title = {Packet-based dynamic control for nonlinear networked systems}, booktitle = {IEEE International Conference on Decision and Control (CDC2013)}, year = {2013}, pages = {6597,6603}, address = {Florence, Italy}, keywords = {Embedded Control, Robotics}, doi = {10.1109/CDC.2013.6760933}, author = {S. Falasca and M. Gamba and L. Greco and A. Chaillet and A. Bicchi} } @conference {1582, title = {Packet-Based Dynamic Control of a Furuta Pendulum over Ethernet}, booktitle = {Mediterranean Conference on Control and Automation (MED {\textquoteright}13)}, year = {2013}, month = {25-28 June 2013 }, pages = {464 - 470}, address = {Platanias-Chania, Crete, Greece}, abstract = {

This paper presents experimental results of the application of Packet-Based Control approach with dynamic controller on a real plant: the Furuta Pendulum. Despite its easiness of realization, Furuta Pendulum presents some features useful for our purposes, such as pretty non-linear dynamics, unstable equilibrium point and heavy dynamical inaccuracies. The network communication channel has been implemented using an Ethernet network. Packet-Based controller has been tested and compared with a classic local controller for different time-varying actuation delays. Results obtained corroborate the validity of the proposed architecture and highlight the robustness of this approach in the presence of actuation delays.

}, keywords = {Embedded Control, Robotics}, issn = {978-1-4799-0995-7}, doi = {10.1109/MED.2013.6608763}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=\&arnumber=6608763\&queryText\%3Dfalasca+gamba}, author = {T. Fabbri and D. Fenucci and S. Falasca and M. Gamba and A. Bicchi} } @conference {1436, title = {A real time robust observer for an agonist antagonist variable stiffness actuator}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2013)}, year = {2013}, note = {

Best Paper Award Finalist

}, pages = {3988 - 3993}, address = {Karlsruhe, Germany, May 6-10, 2013 }, keywords = {Robotics}, url = {10.1109/ICRA.2013.6631139 }, author = {T. Menard and G. Grioli and A. Bicchi} } @article {1563, title = {On the Robust Synthesis of Logical Consensus Algorithms for Distributed Intrusion Detection}, journal = {Automatica}, volume = {49}, year = {2013}, pages = {2339 - 2350}, keywords = {Embedded Control, Robotics}, doi = {10.1016/j.automatica.2013.04.033}, author = {A. Fagiolini and A. Bicchi} } @conference {1759, title = {Shortest paths for wheeled robots with limited Field-Of-View: introducing the vertical constraint}, booktitle = {IEEE Conference on Decision and Control}, year = {2013}, pages = {5143 - 5149}, address = {Florence, Italy}, keywords = {Robotics}, author = {P Salaris and A. Cristofaro and L. Pallottino and A. Bicchi} } @conference {1987, title = {Soft-Actuators in Cyclic Motion: Analytical Optimization of Stiffness and Pre-Load}, booktitle = {IEEE-RAS International Conference on Humanoid Robots}, year = {2013}, address = {Atlanta, Georgia, USA}, keywords = {Robotics}, author = {A. Velasco and G M Gasparri and M. Garabini and L. Malagia and P Salaris and A. Bicchi} } @conference {1788, title = {A Strategy for Dynamic Controller Emulation in Packet-Based Networked Control}, booktitle = {International Conference on Informatics in Control (ICINCO {\textquoteright}13)}, year = {2013}, pages = {29-38}, address = {Reykjav{\'\i}k, Iceland}, keywords = {Embedded Control, Robotics}, doi = {10.5220/0004427100290038}, author = {S. Falasca and M. Gamba and A. Bicchi} } @article {1230, title = {Synergy-Based Hand Pose Sensing: Optimal Glove Design}, journal = {International Journal of Robotics Research}, volume = {32}, year = {2013}, pages = {396-406}, abstract = {

In this paper we study the problem of improving human hand pose sensing device performance by exploiting the knowledge on how humans most frequently use their hands in grasping tasks. In a companion paper we studied the problem of maximizing the reconstruction accuracy of the hand pose from partial and noisy data provided by any given pose sensing device (a sensorized "glove") taking into account statistical a priori information. In this paper we consider the dual problem of how to design pose sensing devices, i.e. how and where to place sensors on a glove, to get maximum information about the actual hand posture. We study the continuous case, whereas individual sensing elements in the glove measure a linear combination of joint angles, the discrete case, whereas each measure corresponds to a single joint angle, and the most general hybrid case, whereas both continuous and discrete sensing elements are available. The objective is to provide, for given a priori information and fixed number of measurements, the optimal design minimizing in average the reconstruction error. Solutions relying on the geometrical synergy definition as well as gradient flow-based techniques are provided. Simulations of reconstruction performance show the effectiveness of the proposed optimal design.

}, keywords = {Robotics}, doi = {10.1177/0278364912474079}, author = {M. Bianchi and P Salaris and A. Bicchi} } @article {1231, title = {Synergy-based Hand Pose Sensing: Reconstruction Enhancement}, journal = {International Journal of Robotics Research}, volume = {32}, year = {2013}, pages = { 407-424}, abstract = {

Low-cost sensing gloves for reconstruction posture provide measurements which are limited under several regards. They are generated through an imperfectly known model, are subject to noise, and may be less than the number of Degrees of Freedom (DoFs) of the hand. Under these conditions, direct reconstruction of the hand posture is an ill-posed problem, and performance can be very poor. This paper examines the problem of estimating the posture of a human hand using(low-cost) sensing gloves, and how to improve their performance by exploiting the knowledge on how humans most frequently use their hands. To increase the accuracy of pose reconstruction without modifying the glove hardware - hence basically at no extra cost - we propose to collect, organize, and exploit information on the probabilistic distribution of human hand poses in common tasks. We discuss how a database of such an a priori information can be built, represented in a hierarchy of correlation patterns or postural synergies, and fused with glove data in a consistent way, so as to provide a good hand pose reconstruction in spite of insufficient and inaccurate sensing data. Simulations and experiments on a low-cost glove are reported which demonstrate the effectiveness of the proposed techniques.

}, keywords = {Robotics}, doi = {10.1177/0278364912474078}, author = {M. Bianchi and P Salaris and A. Bicchi} } @conference {1664, title = {A synergy-driven approach to a myoelectric hand}, booktitle = {13TH International Conference on Rehabilitation Robotics}, year = {2013}, pages = {1 - 6}, address = {June 24-26, 2013, Seattle, WA.}, keywords = {Haptics, Robotics}, url = {10.1109/ICORR.2013.6650377 }, author = {S. B. Godfrey and A. Ajoudani and M. G. Catalano and G. Grioli and A. Bicchi} } @conference {1446, title = {SynGrasp: a MATLAB Toolbox for Grasp Analysis of Human and Robotic Hands}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2013)}, year = {2013}, pages = {1088 - 1093}, keywords = {Robotics}, url = {10.1109/ICRA.2013.6630708 }, author = {M. Malvezzi and G. Gioioso and G. Salvietti and D Prattichizzo and A. Bicchi} } @conference {1435, title = {Tele-Impedance based Stiffness and Motion Augmentation for a Knee Exoskeleton Device}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2013)}, year = {2013}, pages = {2194 - 2200}, keywords = {Robotics}, url = {10.1109/ICRA.2013.6630872}, author = {N. Karavas and A. Ajoudani and N G Tsagarakis and J. Saglia and A. Bicchi and D. G. Caldwell} } @conference {1666, title = {Teleimpedance Control of a Synergy-Driven Anthropomorphic Hand}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2013}, year = {2013}, month = {November 3-7}, pages = {1985 - 1991}, address = {Tokyo, Japan}, keywords = {Haptics, Robotics}, doi = {10.1109/IROS.2013.6696620 }, author = {A. Ajoudani and S. B. Godfrey and M. G. Catalano and G. Grioli and N G Tsagarakis and A. Bicchi} } @article {1698, title = {Variable Impedance Actuators: a Review}, journal = {Robotics and Autonomous Systems}, volume = {61}, year = {2013}, note = {

Available online 6 August 2013

}, month = {12/2013}, pages = {1601{\textendash}1614}, abstract = {

Variable Impedance Actuators (VIA) have received increasing attention in recent years as many novel applications involving interactions with an unknown and dynamic environment including humans require actuators with dynamics that are not well-achieved by classical stiff actuators. This paper presents an overview of the different VIAs developed and proposes a classification based on the principles through which the variable stiffness and damping are achieved. The main classes are active impedance by control, inherent compliance and damping actuators, inertial actuators, and combinations of them, which are then further divided into subclasses. This classification allows for designers of new devices to orientate and take inspiration and users of VIA{\textquoteright}s to be guided in the design and implementation process for their targeted application.

}, keywords = {Robotics, Soft robotics, Variable Impedance Actuators}, url = {http://www.sciencedirect.com/science/article/pii/S0921889013001188}, author = {B. Vanderborght and A Albu-Schaeffer and A. Bicchi and E. Burdet and D. G. Caldwell and R. Carloni and M. G. Catalano and O. Eiberger and W. Friedl and G. Ganesh and M. Garabini and M. Grebenstein and G. Grioli and S. Haddadin and H. Hoppner and A. Jafari and M. Laffranchi and D. Lefeber and F. Petit and S. Stramigioli and N G Tsagarakis and M. Van Damme and R. Van Ham and L. C. Visser and S. Wolf} } @conference {1241, title = {Adaptive Synergies: an approach to the design of under-actuated robotic hands}, booktitle = {International Conference of Intelligent Robots and Systems - IROS 2012}, year = {2012}, month = {October 7 - 12}, pages = {1251 - 1256 }, address = {Vilamoura, Algarve, Portugal}, keywords = {Robotics}, doi = {10.1109/IROS.2012.6385881 }, author = {G. Grioli and M. G. Catalano and E. Silvestro and S. Tono and A. Bicchi} } @conference {1188, title = {Adaptive Synergies for a Humanoid Robot Hand}, booktitle = {IEEE-RAS International Conference on Humanoid Robots}, year = {2012}, note = {

Best Paper Award

}, pages = {7-14}, address = {Osaka, Japan}, keywords = {Robotics}, author = {M. G. Catalano and G. Grioli and A. Serio and E. Farnioli and C. Piazza and A. Bicchi} } @inbook {1237, title = {Artificially Rendered Cutaneous Cues for a New Generation of Haptic Displays}, booktitle = {Springer Series on Touch and Haptic Systems - part 2}, volume = {Immersive Multimodal Interactive Presence}, year = {2012}, pages = {171 - 188}, publisher = {Springer}, organization = {Springer}, keywords = {Robotics}, doi = {10.1007/978-1-4471-2754-3_10}, author = {E. P. Scilingo and M. Bianchi and N. Vanello and V. Hartwig and L. Landini and A. Bicchi} } @conference {1398, title = {Calibration and Test of a Multi-Touch Tactile Object}, booktitle = {International Conference of Intelligent Robots and Systems - IROS 2012}, year = {2012}, address = {Algrave, Portugal}, keywords = {Robotics}, author = {A. Serio and M Gabiccini and I. Sarakoglou and A. Bicchi} } @article {PBB11, title = {Consensus Computation in Unreliable Networks: A System Theoretic Approach}, journal = {IEEE Transactions on Automatic Control}, volume = {57}, year = {2012}, pages = {90 - 104}, keywords = {Robotics}, author = {F. Pasqualetti and A. Bicchi and F. Bullo} } @article {GCB11, title = {Exploiting Packet Size in Uncertain Nonlinear Networked Control Systems}, journal = {Automatica}, volume = {48}, year = {2012}, pages = {2801 - 2811}, keywords = {Robotics}, author = {L. Greco and A. Chaillet and A. Bicchi} } @conference {FGB12, title = {Grasp and Manipulation Analysis for Synergistic Underactuated Hands Under General Loading Conditions}, booktitle = {International Conference of Robotics and Automation - ICRA 2012}, year = {2012}, month = {May 14 - 18}, pages = {2836 - 2842}, address = {Saint Paul, MN, USA}, keywords = {Robotics}, author = {M Gabiccini and E. Farnioli and A. Bicchi} } @article {1232, title = {Interacting with networks: How does structure relate to controllability in single-leader, consensus networks?}, journal = {Control Systems Magazine}, volume = {32}, year = {2012}, pages = {66 - 73}, keywords = {Embedded Control, Robotics}, author = {M. Egerstedt and S. Martini and M. Cao and K. Camlibel and A. Bicchi} } @article {1233, title = {On Making Robots Understand Safety: Embedding Injury Knowledge into Control}, journal = {International Journal of Robotics Research}, volume = {31}, year = {2012}, pages = {1578-1602}, keywords = {Robotics}, doi = {10.1177/0278364912462256 }, author = {S. Haddadin and S. Haddadin and A. Khoury and T. Rokahr and S. Parusel and R. Burgkart and A. Bicchi and A Albu-Schaeffer} } @article {PMGB11, title = {On the Manipulability Ellipsoids of Underactuated Robotic Hands with Compliance Robotics and Autonomous Systems}, journal = {Robotics and Autonomous Systems, special issue on Autonomous Grasping}, volume = {60}, year = {2012}, note = {

in press, Available online 17 August 2011

}, pages = {337 - 346}, keywords = {Haptics, Robotics}, doi = {10.1016/j.robot.2011.07.014}, author = {D Prattichizzo and M. Malvezzi and M Gabiccini and A. Bicchi} } @conference {GBSPB12, title = {Optimality Principles in Stiffness Control: The VSA Kick}, booktitle = {International Conference of Robotics and Automation - ICRA 2012}, year = {2012}, month = {May 14 - 18}, pages = {3341 - 3346 }, address = {Saint Paul, MN, USA}, keywords = {Robotics}, author = {M. Garabini and A. Passaglia and F. A. W. Belo and P Salaris and A. Bicchi} } @conference {MGCGBB12, title = {Passive impedance control of a Qboid multi-DOF VSA-CubeBot manipulator}, booktitle = {International Conference of Robotics and Automation - ICRA 2012}, year = {2012}, month = {May 14 - 18}, pages = {3335 - 3340 }, address = {Saint Paul, MN, USA}, keywords = {Robotics}, doi = {10.1109/ICRA.2012.6225082 }, author = {M. Mancini and G. Grioli and M. G. Catalano and M. Garabini and F. Bonomo and A. Bicchi} } @article {1236, title = {Shortest Paths for Finned, Winged, Legged and Wheeled Vehicles with Side-Looking Sensors}, journal = {International Journal of Robotics Research}, volume = {31}, year = {2012}, pages = {997-1017}, keywords = {Robotics}, doi = {10.1177/0278364912446005}, author = {P Salaris and L. Pallottino and A. Bicchi} } @conference {1240, title = {Synergy-based Optimal Desing of Hand Pose Sensing}, booktitle = {International Conference of Intelligent Robots and Systems - IROS 2012- JTCF Award}, year = {2012}, month = {October 7 - 12}, pages = {3929 - 3935 }, address = {Vilamoura, Algarve, Portugal}, keywords = {Robotics}, author = {M. Bianchi and P Salaris and A. Bicchi} } @conference {RSGB12, title = {On the Synthesis of Feasible and Prehensile Robotic Grasps}, booktitle = {International Conference of Robotics and Automation - ICRA 2012}, year = {2012}, month = {May 14 - 18}, pages = {p. 550 - 556}, address = {Saint Paul, MN, USA}, keywords = {Robotics}, author = {C. Rosales and R. Suarez and M Gabiccini and A. Bicchi} } @conference {1238, title = {Tele-Impedance: Exploring the Role of Common-Mode and Configuration-Dependant Stiffness}, booktitle = {IEEE-RAS International Conference on Humanoid Robots}, year = {2012}, pages = {363-369}, address = {Osaka, Japan}, keywords = {Robotics}, author = {A. Ajoudani and M Gabiccini and N G Tsagarakis and A Albu-Schaeffer and A. Bicchi} } @article {ATB12, title = {Tele-impedance: Teleoperation with Impedance Regulation Using a Body-Machine Interface}, journal = {International Journal of Robotics Research}, volume = { 31 }, year = {2012}, month = {11/2012}, pages = {1643 - 1656}, chapter = {1643}, keywords = {Robotics}, author = {A. Ajoudani and N G Tsagarakis and A. Bicchi} } @conference {ATB12, title = {Tele-Impedance: Towards Transferring Human Impedance Regulation Skills to Robots}, booktitle = {International Conference of Robotics and Automation - ICRA 2012}, year = {2012}, month = {May 14 - 18}, pages = {382 - 388 }, address = {Saint Paul, MN, USA}, keywords = {Robotics}, author = {A. Ajoudani and N G Tsagarakis and A. Bicchi} } @conference {1239, title = {Towards variable impedance assembly: the VSA peg-in-hole}, booktitle = {IEEE-RAS International Conference on Humanoid Robots}, year = {2012}, address = {Osaka, Japan}, keywords = {Robotics}, author = {L. Balletti and A. Rocchi and F. A. W. Belo and M. G. Catalano and M. Garabini and G. Grioli and A. Bicchi} } @conference {1242, title = {A truly safely moving robot has to know what injury it may cause}, booktitle = {International Conference of Intelligent Robots and Systems - IROS 2012}, year = {2012}, month = {October 7 - 12}, pages = {5406-5413}, address = {Vilamoura, Algarve, Portugal}, keywords = {Robotics}, author = {S. Haddadin and S. Haddadin and A. Khoury and T. Rokahr and S. Parusel and R. Burgkart and A. Bicchi and A Albu-Schaeffer} } @conference {BSTCB12, title = {On the Use of Postural Synergies to Improve Human Hand Pose Reconstruction}, booktitle = {Haptics Symposium}, year = {2012}, month = {March 4 - 7}, pages = {91 - 98}, address = {Vancouver, Canada}, keywords = {Haptics, Robotics}, author = {M. Bianchi and P Salaris and A. Turco and N. Carbonaro and A. Bicchi} } @conference {CGGBDBTB12, title = {A Variable Damping module for Variable Impedance Actuation}, booktitle = {International Conference of Robotics and Automation - ICRA 2012}, year = {2012}, month = {May 14 - 18}, pages = {2666 - 2672}, address = {Saint Paul, MN, USA}, keywords = {Robotics}, author = {M. G. Catalano and G. Grioli and M. Garabini and F. A. W. Belo and A. Di Basco and N G Tsagarakis and A. Bicchi} } @article {1245, title = {Variable Impedance Actuators: Moving the Robots of Tomorrow}, year = {2012}, keywords = {Robotics}, author = {B. Vanderborght and A Albu-Schaeffer and A. Bicchi and E. Burdet and D. G. Caldwell and R. Carloni and M. G. Catalano and G. Ganesh and M. Garabini and G. Grioli and S. Haddadin and A. Jafari and M. Laffranchi and D. Lefeber and F. Petit and S. Stramigioli and N G Tsagarakis and M. Van Damme and R. Van Ham and L. C. Visser and S. Wolf} } @conference {1243, title = { Velvet fingers: A dexterous gripper with active surfaces}, booktitle = {International Conference of Intelligent Robots and Systems - IROS 2012}, year = {2012}, month = {October 7 - 12}, pages = {1257 - 1263 }, address = {Vilamoura, Algarve, Portugal}, keywords = {Robotics}, author = {V. Tincani and M. G. Catalano and E. Farnioli and M. Garabini and G. Grioli and G Fantoni and A. Bicchi} } @conference {MFB11, title = {Behavior classification, security, and consensus in societies of robots}, booktitle = {Automatica.it 2011}, year = {2011}, note = {

poster presentation

}, month = {September, 7 - 9}, address = {Pisa, Italy}, keywords = {Embedded Control, Robotics}, author = {S. Martini and A. Fagiolini and A. Bicchi} } @conference {MFZB11, title = {Decentralized Species Classification in Societies of Autonomous and Heterogenous Robots}, booktitle = {2011 IEEE International Conference on Robotics and Automation}, year = {2011}, month = {May 9 - 13}, pages = {32 - 39}, address = {Shangai, China}, keywords = {Embedded Control, Robotics}, author = {S. Martini and A. Fagiolini and G. Zichittella and M. Egerstedt and A. Bicchi} } @conference {SGSTB11, title = {A decoupled Impedance observer for a Variable Stiffness Robot}, booktitle = {2011 IEEE International Conference on Robotics and Automation}, year = {2011}, month = {May 9 - 13}, pages = {5548 - 5553}, address = {Shangai, China}, keywords = {Robotics}, author = {A. Serio and G. Grioli and I. Sardellitti and N G Tsagarakis and A. Bicchi} } @article {GFB11, title = {Design and Stability Analysis for Anytime Control via Stochastic Scheduling}, journal = {IEEE Trans. on Automat. Contr.}, volume = {56}, number = {3}, year = {2011}, pages = {571 - 585}, keywords = {Embedded Control, Robotics}, author = {L. Greco and D. Fontanelli and A. Bicchi} } @conference {GBB11, title = {Dynamic Optimization of Tendon Tensions in Biomorphically Designed Hands with Rolling Constraints}, booktitle = {2011 IEEE International Conference on Robotics and Automation}, year = {2011}, month = {May 9 - 13}, pages = {2698 - 2704}, address = {Shangai, China}, keywords = {Haptics, Robotics}, author = {M Gabiccini and M. Branchetti and A. Bicchi} } @conference {VSB11, title = {Embodying Desired Behavior in Variable Stiffness Actuators}, booktitle = {2011 Congress of the International Federation of Automatic Control - IFAC 2011}, year = {2011}, month = {August 28 - Sept}, pages = {9733 - 9738}, address = {Milano, italy}, keywords = {Robotics}, author = {L. C. Visser and S. Stramigioli and A. Bicchi} } @conference {GCB11, title = {Exploiting Packet Size in Uncertain Nonlinear Networked Control Systems}, booktitle = {2011 Congress of the International Federation of Automatic Control - IFAC 2011}, year = {2011}, month = {August 28 - Sept}, pages = {14404 - 14409}, address = {Milano, italy}, keywords = {Embedded Control, Robotics}, author = {L. Greco and A. Chaillet and A. Bicchi} } @conference {SPHB11, title = {From Optimal Planning to Visual Servoing with Limited FOV}, booktitle = {2011 IEEE/RSJ International Conference on Intelligent RObots and Systems}, year = {2011}, month = {September 25 - 3}, pages = {2817-2824}, address = {S. Francisco, USA}, keywords = {Embedded Control, Robotics}, author = {P Salaris and L. Pallottino and S. Hutchinson and A. Bicchi} } @conference {PBB11, title = {A graph theoretic characterization of power network vulnerabilities}, booktitle = {2011 American Control Conference}, year = {2011}, month = {June 29 - July 1}, pages = {3918 - 3923}, address = {San Francisco, CA}, keywords = {Robotics}, author = {F. Pasqualetti and A. Bicchi and F. Bullo} } @conference {SCGGB11, title = {The Hand Embodied}, booktitle = {Automatica.it 2011}, year = {2011}, note = {

poster presentation

}, month = {September, 7 - 9}, address = {Pisa, Italy}, keywords = {Haptics, Robotics}, author = {A. Serio and M. G. Catalano and G. Grioli and M Gabiccini and A. Bicchi} } @conference {BSB11, title = {Haptic interfaces: new strategies to convey tactile information}, booktitle = {Automatica.it 2011}, year = {2011}, note = {

poster presentation

}, month = {September, 7 - 9}, address = {Pisa, Italy}, keywords = {Haptics, Robotics}, author = {M. Bianchi and E. P. Scilingo and A. Bicchi} } @article {DPB11, title = {Left invertibility of discrete-time output-quantized systems: the linear case with finite inputs}, journal = {Mathematics of Control, Signals, and Systems}, volume = {23}, number = {1 - 2}, year = {2011}, note = {

published online 8 Sept. 2011

}, month = {November, 16}, pages = {117 - 139}, abstract = {

This paper studies left invertibility of discrete-time linear outputquantized systems. Quantized outputs are generated according to a given partition of the state-space, while inputs are sequences on a nite alphabet. Left invertibility, i.e. injectivity of I/O map, is reduced to left D-invertibility, under suitable conditions. While left invertibility takes into account membership to sets of a given partition, left D-invertibility considers only membership to a single set, and is much easier to detect. The condition under which left invertibility and left D-invertibility are equivalent is that the elements of the dynamic matrix of the system form an algebraically independent set. Our main result is a method to compute left D-invertibility (so also left invertibility for a full measure matrix set) for all linear systems with no eigenvalue of modulus one. Therefore we are able to check left invertibility of output-quantized linear systems for a full measure matrices set. Some examples are presented to show the application of the proposed method.

}, keywords = {Robotics}, doi = {10.1007/s00498-011-0063-x}, author = {N. Dubbini and B. Piccoli and A. Bicchi} } @conference {DMB11, title = {Left invertibility of output-quantized MISO linear systems}, booktitle = {2011 Congress of the International Federation of Automatic Control - IFAC2011}, year = {2011}, month = {August 28 - Sept}, pages = {11278 - 11283}, address = {Milano, italy}, abstract = {

This paper studies left invertibility of single-output discrete-time quantized linear systems. Quantized outputs are generated according to a given partition of the state-space, while inputs are sequences on a finite alphabet. Left invertibility deals with the possibility of recovering unknown inputs from the only knowledge of the outputs. It is reduced, under suitable conditions, to left D-invertibility: while left invertibility takes into account membership to sets of a given partition, left D-invertibility considers only membership to a single set, and is easily (and algorithmically) detectable. Our main result is a sufficient condition for the equivalence between left invertibility and left D-invertibility in MISO system. In unidimensional systems the equivalence is valid except at most a finite (and computable) number of cases. These results allows the effective detection of left invertibility by means of left Dinvertibility, which is algorithmically detectable. An example with effective computations is presented to show the application of the proposed method.

}, keywords = {Embedded Control, Robotics}, author = {N. Dubbini and M. Monge and A. Bicchi} } @article {BGS11, title = {Modeling Natural and Artificial Hands with Synergies}, journal = {Philosophical Transactions of the Royal Society B}, volume = {366}, year = {2011}, pages = {3153 - 3161}, keywords = {Haptics, Robotics}, doi = {10.1098/rstb.2011.0152}, author = {A. Bicchi and M Gabiccini and M. Santello} } @booklet {11, title = {Optimal synthesis for nonholonomic vehicles with constrained side sensors}, year = {2011}, note = {

Technical Report

}, keywords = {Embedded Control, Robotics}, author = {P Salaris and L. Pallottino and A. Bicchi} } @conference {GPBSB11, title = {Optimality Principles in Variable Stiffness Control: the VSA Hammer}, booktitle = {2011 IEEE/RSJ International Conference on Intelligent RObots and Systems}, year = {2011}, month = {September 25 - 3}, pages = {3770 - 3775}, address = {S. Francisco, USA}, keywords = {Robotics}, author = {M. Garabini and A. Passaglia and F. A. W. Belo and P Salaris and A. Bicchi} } @conference {GB11, title = {A Real-time Parametric Stiffness Observer for VSA devices}, booktitle = {2011 IEEE International Conference on Robotics and Automation}, year = {2011}, month = {May 9 - 13}, pages = {5535 - 5540}, address = {Shangai, China}, keywords = {Robotics}, author = {G. Grioli and A. Bicchi} } @conference {MDBGB11, title = {Robust Network Agreement on Logical Information}, booktitle = {2011 Congress of the International Federation of Automatic Control - IFAC 2011}, year = {2011}, month = {August 28 - Sept}, pages = {13905 - 13911}, address = {Milano, italy}, keywords = {Embedded Control, Robotics}, author = {S. Martini and D. Di Baccio and A. Fagiolini and A. Bicchi} } @article {GBPM11, title = {On the Role of Hand Synergies in the Optimal Choice of Grasping Forces}, journal = {Autonomous Robots [special issue on RSS2010]}, volume = {31}, number = {2 - 3}, year = {2011}, pages = {235 - 252}, keywords = {Haptics, Robotics}, doi = {10.1007/s10514-011-9244-1}, author = {M Gabiccini and A. Bicchi and D Prattichizzo and M. Malvezzi} } @conference {SPB11, title = {Shortest Paths With Side Sensor}, booktitle = {2011 IEEE International Conference on Robotics and Automation}, year = {2011}, month = {May 9 - 13}, pages = {4875 - 4882}, address = {Shangai, China}, keywords = {Embedded Control, Robotics}, author = {P Salaris and L. Pallottino and A. Bicchi} } @conference {GFMB11, title = {Structural Properties of Compliant Grasps with Underactuated Robotic Hands}, booktitle = {XX Congresso Aimeta}, year = {2011}, note = {

ISBN 978-88-906340-1-7 (online); ISBN 978-88-906340-0-0 (print)

}, month = {September, 12}, address = {Bologna, Italy}, keywords = {Haptics, Robotics}, author = {M Gabiccini and E. Farnioli and M. Malvezzi and A. Bicchi} } @conference {ATB11, title = {Tele-Impedance: Preliminary Results on Measuring and Replicating Human Arm Impedance in Tele Operated Robots}, booktitle = {IEEE International Conference on Robotics and Biomimetics - ROBIO 2011}, year = {2011}, note = {

Accepted, youtube: http://www.youtube.com/watch?v=KPO6IO7Tr-Q

}, month = {December 7 - 11}, pages = {216 - 223}, address = {Phuket, Thailand}, keywords = {Robotics}, author = {A. Ajoudani and N G Tsagarakis and A. Bicchi} } @conference {GCGSSBMBP11, title = {Variable stiffness actuators: muscles for the next generation of robots}, booktitle = {Automatica.it 2011}, year = {2011}, note = {

poster presentation

}, month = {September, 7 - 9}, address = {Pisa, Italy}, keywords = {Robotics}, author = {G. Grioli and M. G. Catalano and M. Garabini and F. Bonomo and A. Serio and P Salaris and F. A. W. Belo and M. Mancini and A. Bicchi and A. Passaglia} } @conference {CGGBB11, title = {VSA - CubeBot. A modular variable stiffness platform for multi degrees of freedom systems}, booktitle = {2011 IEEE International Conference on Robotics and Automation}, year = {2011}, month = {May 9 - 13}, pages = {5090 - 5095}, address = {Shangai, China}, keywords = {Robotics}, author = {M. G. Catalano and G. Grioli and M. Garabini and F. Bonomo and M. Mancini and N G Tsagarakis and A. Bicchi} } @conference {BSB10, title = {3 known landmarks are enough for solving planar bearing SLAM and fully reconstruct unknown inputs}, booktitle = {Intelligent Robots and Systems (IROS), 2010 IEEE/RSJ International Conference on}, year = {2010}, month = {October}, pages = {2539 -2545}, address = {St. Louis MO USA}, keywords = {Embedded Control, Robotics}, doi = {10.1109/IROS.2010.5648896}, author = {F. A. W. Belo and P Salaris and A. Bicchi} } @article {MEB09, title = {Controllability analysis of multi-agent systems using relaxed equitable partitions}, journal = {Int. J. Systems, Control and Communications}, volume = {2}, number = {1,2,3}, year = {2010}, pages = {100-121}, abstract = {

This paper investigates the issue of how to make decentralised networks amenable to external control, i.e. how to ensure that they are appropriately organised so that they can be effectively

}, keywords = {Embedded Control, Robotics}, author = {S. Martini and M. Egerstedt and A. Bicchi} } @conference {WPB-ICRA10, title = {Controllability for Pairs of Vehicles Maintaining Constant Distance}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2010)}, year = {2010}, month = {May 3 - 8}, pages = {342 - 349}, address = {Anchorage, Alaska}, keywords = {Embedded Control, Robotics}, author = {H. Wang and L. Pallottino and A. Bicchi} } @conference {WPB_cdc10, title = {Controllability Properties for Aircraft Formations}, booktitle = {International Conference on Decision and Control - CDC 2010}, year = {2010}, pages = {2047 - 2054}, keywords = {Embedded Control, Robotics}, author = {H. Wang and L. Pallottino and A. Bicchi} } @conference {FBCABB-ICRA10, title = {Design and Control of a Novel 3D Casting Manipulator}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2010)}, year = {2010}, month = {May 3 - 8}, pages = {4169 - 4174}, address = {Anchorage, Alaska}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and F. A. W. Belo and M. G. Catalano and S. Alicino and F. Bonomo and A. Bicchi} } @conference {CSB-ICRA10, title = {Design for Variable Stiffness Actuation based on Enumeration and Analysis of Performance}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2010)}, year = {2010}, month = {May 3 - 8}, pages = {3285 - 3291}, address = {Anchorage, Alaska}, keywords = {Embedded Control, Robotics}, author = {M. G. Catalano and R. Schiavi and A. Bicchi} } @article {QFGPB10, title = {Design of Embedded Controllers Based on Anytime Computing}, journal = {IEEE Trans. Industrial Infor.}, volume = {6}, number = {4}, year = {2010}, pages = {492 - 502}, abstract = {

In this paper, we present a methodology for designing embedded controllers based on the so-called anytime control paradigm. A control law is split into a sequence of subroutine calls, each one fulfilling a control goal and refining the result produced by the previous one. We propose a design methodology to define a feedback controller structured in accordance with this paradigm and show how a switching policy of selecting the controller subroutines can be designed that provides stability guarantees for the closed-loop system. The cornerstone of this construction is a stochastic model describing the probability of executing, in each activation of the controller, the different subroutines. We show how this model can be constructed for realistic real-time task sets and provide an experimental validation of the approach.

}, keywords = {Embedded Control, Robotics}, author = {A. Quagli and D. Fontanelli and L. Greco and L. Palopoli and A. Bicchi} } @conference {PCBB10, title = {Distributed Estimation and Detection under Local Information}, booktitle = {IFAC Workshop on Distributed Estimation and Control in Networked Systems}, year = {2010}, month = {Sept 13-14}, pages = {263-268}, address = {Annecy, France}, keywords = {Embedded Control, Robotics}, author = {F. Pasqualetti and R. Carli and A. Bicchi and F. Bullo} } @conference {PCBB, title = {Identifying Cyber Attacks via Local Model Information}, booktitle = {International Conference on Decision and Control - CDC 2010}, year = {2010}, month = {December}, pages = {5961 - 5966}, address = {Atlanta, USA}, keywords = {Embedded Control, Robotics}, author = {F. Pasqualetti and R. Carli and A. Bicchi and F. Bullo} } @article {DPB10, title = {Left invertibility of discrete systems with finite inputs and quantized output}, journal = {International Journal Of Control}, volume = {83}, number = {4}, year = {2010}, pages = {798 - 809}, abstract = {

The aim of this paper is to address left invertibility for dynamical systems with inputs and outputs in discrete sets. We study systems which evolve in discrete time within a continuous state-space; quantized outputs are generated by the system according to a given partition of the state-space, while inputs are arbitrary sequences of symbols in a finite alphabet, which are associated to specific actions on the system. Our main results are obtained under some contractivity hypotheses. The problem of left invertibility, i.e. recovering an unknown input sequence from the knowledge of the corresponding output string, is addressed using the theory of Iterated Function Systems (IFS), a tool developed for the study of fractals. We show how the IFS naturally associated to a system and the geometric properties of its attractor are linked to the invertibility property of the system. Our main result is a necessary and sufficient condition for left invertibility and uniform left invertibility for joint contractive systems. In addition, an algorithm is proposed to recover inputs from output strings. A few examples are presented to illustrate the application of the proposed method.

}, keywords = {Embedded Control, Robotics}, author = {N. Dubbini and B. Piccoli and A. Bicchi} } @conference {DCB, title = {Left invertibility of output-quantized systems: an application to cryptography}, booktitle = {International Conference on Decision and Control - CDC 2010}, year = {2010}, month = {December}, pages = {4078-4083}, address = {Atlanta, USA}, abstract = {

In this paper a secure communication method is proposed, based on left invertibility of output-quantized dynamical systems. The sender uses an output-quantized linear system with a feedback function to encode messages, which are sequences of inputs of the system. So left invertibility property enables the receiver to recover the messages. The secret key is formed by the system

}, keywords = {Robotics}, author = {N. Dubbini and A. Carluccio and A. Bicchi} } @article {1756, title = {Mechanism of Motor reduction with variable rigidity and rapidly controllable}, year = {2010}, address = {USA}, keywords = {Robotics}, issn = {US7699731}, author = {A. Bicchi and G. Tonietti} } @conference {FBQB10, title = {A Modular and Layered Cosimulator for Networked Control Systems}, booktitle = {Mediterranean Conference on Control and Automation}, year = {2010}, month = {June, 23 - 25}, pages = {273 - 279}, address = {Marrakech, Morocco}, keywords = {Embedded Control, Robotics}, author = {S. Falasca and C Belsito and A. Quagli and A. Bicchi} } @conference {PMB10, title = {On motion and force controllability of grasping hands with postural synergies}, booktitle = {Proceedings of Robotics: Science and Systems}, year = {2010}, month = {June}, address = {Zaragoza, Spain}, keywords = {Haptics, Robotics}, author = {D Prattichizzo and M. Malvezzi and A. Bicchi} } @conference {WPb_cdc10_2, title = {Motion planning for Formations of Dubins Vehicles}, booktitle = {International Conference on Decision and Control - CDC 2010}, year = {2010}, pages = {2263 - 2269}, keywords = {Embedded Control, Robotics}, author = {H. Wang and L. Pallottino and A. Bicchi} } @conference {BSSB, title = {A new fabric based softness display}, booktitle = {Symposium on Haptic Interfaces for Virtual Environments and Teleoperator Systems}, year = {2010}, note = {

Best Student Paper and Best Paper Award Finalist

}, month = {March 25-16}, pages = {108 - 112}, address = {Waltham,Massachusetts, USA}, keywords = {Haptics, Robotics}, author = {M. Bianchi and A. Serio and E. P. Scilingo and A. Bicchi} } @conference {GB10, title = {A Non-invasive Real-Time Method for Measuring Variable Stiffness}, booktitle = {Robotics Science and Systems}, year = {2010}, month = {June}, address = {Zaragoza, Spain}, keywords = {Robotics}, author = {G. Grioli and A. Bicchi} } @conference {FMEBG, title = {Observability and Controllability Detection of Multi-Agent Systems through Decentralized Laplacian Spectrum Estimation}, booktitle = {International Conference on Decision and Control - CDC 2010}, year = {2010}, pages = {5775 - 5780}, keywords = {Embedded Control, Robotics}, author = {M. Franceschelli and S. Martini and M. Egerstedt and A. Bicchi and A. Giua} } @article {SBGBB10, title = {Rendering Softness: Integration of kinaesthetic and cutaneous information in a haptic device}, journal = {Transactions on Haptics}, volume = {3}, number = {2}, year = {2010}, note = {

Best Student Paper and Best Paper Award Finalist

}, pages = {109 - 118}, keywords = {Haptics, Robotics}, author = {E. P. Scilingo and M. Bianchi and G. Grioli and A. Bicchi} } @conference {BG10, title = {On the Role of Hand Synergies in the Optimal Choice of Grasping Forces}, booktitle = {Robotics Science and Systems}, year = {2010}, month = {June, 27}, address = {Zaragoza, Spain}, keywords = {Haptics, Robotics}, author = {M Gabiccini and A. Bicchi} } @conference {FMDBB10, title = {A Self-Routing Protocol for Distributed Consensus on Logical Information}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems}, year = {2010}, month = {October, 18 - 22}, pages = {5151 - 5156}, address = {Taipei, Taiwan}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and S. Martini and D. Di Baccio and A. Bicchi} } @article {SPFB10, title = {Shortest Paths for a Robot with Nonholonomic and Field-of-View Constraints}, journal = {IEEE Trans. on Robotics}, volume = {26}, number = {2}, year = {2010}, pages = {269 - 281}, keywords = {Embedded Control, Robotics}, author = {P Salaris and D. Fontanelli and L. Pallottino and A. Bicchi} } @article {BFP10, title = {Towards a Society of Robots: Behaviors, Misbehaviors, and Security}, journal = {IEEE Robotics and Automation Magazine}, volume = {17}, number = {4}, year = {2010}, month = {December}, pages = {26 - 36}, keywords = {Robotics}, author = {A. Bicchi and A. Fagiolini and L. Pallottino} } @conference {BGSSB, title = {Validation of a Virtual Reality Environment to Study Anticipatory Modulation of Digit Forces and Position}, booktitle = {Eurohaptics 2010}, series = {Lecture Notes in Computer Science}, volume = {6192/2010}, year = {2010}, month = {July, 8 - 10}, pages = {136 - 143}, address = {Amsterdam (The Netherlands)}, keywords = {Haptics, Robotics}, author = {M. Bianchi and G. Grioli and E. P. Scilingo and M. Santello and A. Bicchi} } @inbook {FSBB10, title = {Visual Servoing via Advanced Numerical Methods}, volume = {401}, year = {2010}, pages = {335 - 360}, publisher = {Springer}, organization = {Springer}, chapter = {Unicycle{\textendash}like Robots with Eye-In-Hand Monocular Cameras: from PBVS Towards IBVS}, keywords = {Robotics}, author = {D. Fontanelli and P Salaris and F. A. W. Belo and A. Bicchi}, editor = {Graziano Chesi and Koichi Hashimoto} } @conference {CGBSB10, title = {VSA-HD: From the Enumeration Analysis to the Prototypical Implementation}, booktitle = {IEEE/RSJ International Conference on Intelligent RObots and Systems}, year = {2010}, month = {October}, pages = {3676 - 3681}, address = {St. Louis MO USA}, keywords = {Embedded Control, Robotics}, author = {M. G. Catalano and G. Grioli and F. Bonomo and R. Schiavi and A. Bicchi} } @conference {QFGPB-ETFA09, title = {Designing Real-Time Embedded Controllers using the Anytime Computing Paradigm}, booktitle = {IEEE International Conference on Emerging Technology and Factory Automation}, year = {2009}, month = {September, 12 - }, pages = {1 - 8}, address = {Palma de Mallorca, Spain}, abstract = {

In this paper we present a methodology for designing embedded controllers with a variable accuracy. The adopted paradigm is the so called any-time control, which derives from the computing paradigm known as "imprecise computation". The most relevant contributions of the paper are a procedure for designing an incremental control law, whose different pieces cater for increasingly aggressive control requirements, and a modelling technique for the execution platform that allows us to design provably correct switching policies for the controllers. The methodology is validated by both simulations and experimental results.

}, keywords = {Embedded Control, Robotics}, doi = {10.1109/ETFA.2009.5347086}, author = {A. Quagli and D. Fontanelli and L. Greco and L. Palopoli and A. Bicchi} } @conference {FMDB-NecSys09, title = {Distributed Consensus on Boolean Information}, booktitle = {1st IFAC Workshop on Estimation and Control of Networked Systems (NecSys{\textquoteright}09)}, year = {2009}, month = {September, 24 - }, pages = {72 - 77}, address = {Venice, Italy}, abstract = {

In this paper we study the convergence towards consensus on information in a distributed system of agents communicating over a network. The particularity of this study is that the information on which the consensus is seeked is not represented by real numbers, rather by logical values or compact sets. Whereas the problems of allowing a network of agents to reach a consensus on logical functions of input events, and that of agreeing on set-valued information, have been separately addressed in previous work, in this paper we show that these problems can indeed be attacked in a unified way in the framework of Boolean distributed information systems. Based on a notion of contractivity for Boolean dynamical systems, a necessary and suficient condition ensuring the global convergence toward a unique equilibrium point is presented. This result can be seen as a first step toward the de nition of a unified framework to uniformly address all consensus problems on Boolean algebras.

}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and S. Martini and N. Dubbini and A. Bicchi} } @conference {FBB-ICRA09, title = {Dynamic Distributed Intrusion Detection for Secure Multi-Robot Systems}, booktitle = {Int. Conference of Robotics and Automation}, year = {2009}, month = {May, 12 - 17}, pages = {2723 - 2728}, address = {Kobe, Japan}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and F. Babboni and A. Bicchi} } @conference {SFB-ICRA09, title = {Integration of Active and Passive Compliance Control for Safe Human-Robot Coexistence}, booktitle = {Int. Conference of Robotics and Automation}, year = {2009}, month = {May, 12 - 17}, pages = {259 - 264}, address = {Kobe, Japan}, keywords = {Embedded Control, Robotics}, author = {R. Schiavi and F. Flacco and A. Bicchi} } @conference {BSSB09, title = {A new softness display based on bi-elastic fabric}, booktitle = {World Haptics}, year = {2009}, note = {

poster presentation

}, month = {March, 18 - 20}, pages = {382 - 383}, address = {Salt Lake City, USA}, abstract = {

Haptic perception allows to explore and recognize an object by conveying several physical information to mechano-receptors and thermo-receptors lying into our skin throughout the body. The term

}, keywords = {Haptics, Robotics}, author = {M. Bianchi and A. Serio and E. P. Scilingo and A. Bicchi} } @conference {DLFSB-IROS09, title = {Nonlinear Decoupled Motion-Stiffness Control and Collision Detection/Reaction for the VSA-II Variable Stiffness Device}, booktitle = {Proc. IEEE/RSJ International Conference on Intelligent RObots and Systems}, year = {2009}, month = {October, 11 - 15}, pages = {5487-5494}, address = {St. Louis MO USA}, abstract = {

Variable Stiffness Actuation (VSA) devices are being used to jointly address the issues of safety and performance in physical human-robot interaction. With reference to the VSA-II prototype, we present a feedback linearization approach that allows the simultaneous decoupling and accurate tracking of motion and stiffness reference profiles. The operative condition that avoids control singularities is characterized. Moreover, a momentum-based collision detection scheme is introduced, which does not require joint torque sensing nor information on the time-varying stiffness of the device. Based on the residual signal, a collision reaction strategy is proposed that takes advantage of the proposed nonlinear control to rapidly let the arm bounce away after detecting the impact, while limiting contact forces through a sudden reduction of the stiffness. Simulations results are presented to illustrate the performance of the overall approach. Extensions to the multi-dof case of robot manipulators equipped with VSA-II devices are also considered.

}, keywords = {Embedded Control, Physical Human-Robot Interaction (pHRI), Robotics}, author = {A. De Luca and F. Flacco and R. Schiavi and A. Bicchi} } @conference {BSSB, title = {Rendering softness: a new fabric yielding display}, booktitle = {Workshop for young researchers on human - friendly robotics - Symposium}, year = {2009}, month = {December 3}, address = {Sestri levante (Ge), Italy}, keywords = {Haptics, Robotics}, author = {M. Bianchi and A. Serio and E. P. Scilingo and A. Bicchi} } @conference {ACBBGSFB-IROS09, title = {A Rough-Terrain, Casting Robot for the ESA Lunar Robotics Challenge}, booktitle = {Proc. IEEE/RSJ International Conference on Intelligent RObots and Systems}, year = {2009}, month = {October, 11 - 15}, pages = {3336-3342}, address = {St. Louis MO USA}, abstract = {

This paper describes the design and implementation of DAVID, a lunar vehicle developed for the European Space Agency (ESA) Lunar Robotics Challenge, presenting severe terrain negotiation and sample acquisition challenges. We discuss in some detail two of the main innovative aspects of our entry to the challenge, i.e. the locomotion system and the sample acquisition system. Motivated by the challenge specifications, a range of different locomotion systems were considered, among which we chose a simple, rugged and effective wheeled system. We provide an account of the choice of five different types of wheels, which were designed, analyzed and experimentally tested in conditions similar to the challenge. The system eventually turned out to be very effective in negotiating 89\% slopes of volcanic terrain on the challenge site, Mount Teide in Tenerife. To reduce the distance to be traveled on the difficult terrain and avoid risks in reaching the lowest parts of a crater, the vehicle was endowed with an innovative sample acquisition system, i.e. a casting manipulator. Casting manipulation is a technique in which the end-effector is thrown, the sample material is acquired, and the end-effector is retrieved using a light tether that acts as a

}, keywords = {Robotics}, author = {S. Alicino and M. G. Catalano and F. Bonomo and F. A. W. Belo and G. Grioli and R. Schiavi and A. Fagiolini and A. Bicchi} } @conference {FMDB-NESTER09, title = {Safety and Security in Networked Robotics Systems via Logical Consensus}, booktitle = {International Workshop on Networked embedded and control system technologies: European and Russian R\&D cooperation (NESTER{\textquoteright}09)}, year = {2009}, month = {July, 2 - 5}, address = {Milan, Italy}, keywords = {Embedded Control, Robotics}, author = {S. Martini and A. Fagiolini and G. Dini and A. Bicchi} } @conference {PBB-CDC09, title = {On the Security of Linear Consensus Networks}, booktitle = {Proc. IEEE International Conference on Decision and Control}, year = {2009}, note = {

General Chairs Recognition Awards for Interactive Papers

}, month = {December, 16 - 1}, pages = {4894 - 4901}, address = {Shangai, China}, abstract = {

The task of performing trustworthy computation in a network of autonomous agents in the presence of misbehaving components is the subject of this work. A solution to this problem is relevant for several coordination, formation, and synchronization tasks. Relying only on the information flow of the control protocol, uncooperative behaviors are revealed using an unknown input observer technique. Necessary and sufficient conditions to detect and correctly identify misbehaving nodes are given, together with a study of the genericity of such conditions. It is shown that generically any node of the network can correctly estimate the state of the other agents, and therefore compute any function of the state, provided that the connectivity of the communication graph is strictly greater than the number of misbehaving nodes. An intrusion detection and identification algorithm is described, and its effectiveness is confirmed through a numerical study.

}, keywords = {Embedded Control, Robotics}, author = {F. Pasqualetti and A. Bicchi and F. Bullo} } @conference {FMB-CASE09, title = {Set-Valued Consensus for Distributed Clock Synchronization}, booktitle = {Proc. IEEE Conference on Automation Science and Engineering}, year = {2009}, month = {August, 22-25}, pages = {116 - 121}, address = {Bangalore}, abstract = {

This paper addresses the clock synchronization problem in a wireless sensor network (WSN) and proposes a distributed solution that consists of a form of consensus, where agents are able to exchange data representing intervals or sets. The solution is based on a centralized algorithm for clock synchronization, proposed by Marzullo, that determines the smallest interval that is in common with the maximum number of measured interval. We first show how to convert such an algorithm into a problem involving only operations on sets, and then we convert it into a set

}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and S. Martini and A. Bicchi} } @conference {PSFB-CDC09, title = {Shortest Paths for Non-holonomic Vehicles with Limited Field of View Camera}, booktitle = {Proc. IEEE International Conference on Decision and Control}, year = {2009}, month = {December, 16 - 1}, pages = {8434 - 8439}, address = {Shangai, China}, abstract = {

This paper presents a complete characterization of shortest paths for unicycle-like nonholonomic mobile robots equipped with a pinhole camera rigidly fixed with limited Field-Of-View (FOV). We preliminarily provide an alphabet of optimal control words and then we demonstrate how to obtain the partition induced by shortest path in the vehicle plane. The word univocally associated to a region encodes the shortest path from any starting point in that region to the goal point of the mobile robot without violating the FOV constraints.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and P Salaris and D. Fontanelli and A. Bicchi} } @inbook {FSBB09_STAR, title = {Visual appearance mapping for optimal vision based servoing}, series = {Springer Tracts in Advanced Robotics (STAR)}, volume = {54 - Experimental Robotics}, year = {2009}, month = {March 28}, pages = {353 - 362}, publisher = {Springer}, organization = {Springer}, keywords = {Robotics}, author = {D. Fontanelli and P Salaris and F. A. W. Belo and A. Bicchi}, editor = {B. Siciliano and O. Khatib and Groen, F.} } @article {FDSBB09, title = {Visual Servoing in the Large}, journal = {International Journal of Robotics Research}, volume = {28}, number = {6}, year = {2009}, month = {June}, pages = {802 - 814}, abstract = {

In this paper we consider the problem of maneuvering an autonomous robot in complex unknown environments using vision. The goal is to accurately servo a wheeled vehicle to a desired posture using only feedback from an on-board camera, taking into account the nonholonomic nature of the vehicle kinematics and the limited field-ofview of the camera. With respect to existing visual servoing schemes, which achieve similar goals locally (i.e. when the desired and actual camera views are sufficiently similar), we propose a method to visually navigate the robot through an extended visual map before eventually reaching the desired goal. The map comprises a set of images, previously stored in an exploratory phase, that convey both topological and metric information regarding the connectivity through feasible robot paths and the geometry of the environment, respectively. Experimental results on a laboratory setup are reported showing the practicality of the proposed approach.

}, keywords = {Embedded Control, Robotics}, author = {D. Fontanelli and A. Danesi and F. A. W. Belo and P Salaris and A. Bicchi} } @conference {GFB08, title = {Anytime Control Algorithms for Real-Time Embedded Systems}, booktitle = {Int Conf of Hybrid Systems: Computation and Control}, series = {Lecture Notes in Computer Science}, volume = {4981/2008}, year = {2008}, pages = {158 - 171}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {St. Louis, MO}, abstract = {

In this paper we consider the problem of designing controllers for linear plants to be implemented in embedded platforms under stringent real-time constraints. These include preemptive scheduling schemes, under which the maximum execution time allowed for control software tasks is uncertain. We propose an {\textquoteleft}{\textquoteleft}anytime control{\textquoteright}{\textquoteright} design approach, consisting in a hierarchy of controllers for the same plant. Higher controllers in the hierarchy provide better closed-loop performance, while typically requiring a larger worst-case execution time. We provide a procedure for the design of controllers which, together with a conditioning process of the stochastic scheduling, provides better performance than prevailing worst case-based design, while guaranteeing almost sure stability of the resulting switching system.

}, keywords = {Embedded Control, Robotics}, author = {D. Fontanelli and L. Greco and A. Bicchi}, editor = {M. Egerstedt and B. Mishra} } @conference {FPVDB08, title = {Consensus-based Distributed Intrusion Detection for Multi-Robot Systems}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2008}, pages = {120 - 127}, abstract = {

This paper addresses a security problem in robotic multi-agent systems, where agents are supposed to cooperate according to a shared protocol. A distributed Intrusion Detection System (IDS) is proposed here, that detects possible non- cooperative agents. Previous work by the authors showed how single monitors embedded on-board the agents can detect non- cooperative behavior, using only locally available information. In this paper, we allow such monitors to share the collected information in order to overcome their sensing limitation. In this perspective, we show how an agreement on the type of behavior of a target-robot may be reached by the monitors, through execution of a suitable consensus algorithm. After formulating a consensus problem over non-scalar quantities, and with a generic update function, we provide conditions for the consensus convergence and an upper bound to its transient duration. Effectiveness of the proposed solution is finally shown through simulation of a case study.

}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and M. Pellinacci and M. Valenti and G. Dini and A. Bicchi} } @conference {MMB-CDC08, title = {Controllability Decompositions of Networked Systems Through Quotient Graphs}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2008}, pages = {5244 - 5249}, keywords = {Embedded Control, Robotics}, author = {S. Martini and M. Egerstedt and A. Bicchi} } @conference {FTBD08, title = {Decentralized Deployment of Mobile Sensors for Optimal Connected Sensing Coverage}, booktitle = {Distributed Computing in Sensor Systems}, series = {Lecture Notes in Computer Science}, volume = {5067/2008}, year = {2008}, pages = {486 - 491}, publisher = {Springer Berlin / Heidelberg}, organization = {Springer Berlin / Heidelberg}, abstract = {

In this paper, we address the optimal connected sensing coverage problem, i.e., how mobile sensors with limited sensing capabilities can cooperatively adjust their locations so as to maximize the extension of the covered area while avoiding any internal "holes", areas that are not covered by any sensor. Our solution consists in a distributed motion algorithm that is based on an original extension of the Voronoi tessellation.

}, keywords = {Embedded Control, Robotics}, url = {http://dx.doi.org/10.1007/978-3-540-69170-9_34}, author = {A. Fagiolini and L. Tani and A. Bicchi and G. Dini} } @conference {CB-CDC08, title = {Delay compensation in packet-switching networked controlled systems}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2008}, pages = {3620 - 3625}, keywords = {Embedded Control, Robotics}, author = {A. Chaillet and A. Bicchi} } @article {BDDLPPSS08, title = {Heterogeneous Wireless Multirobot System}, journal = {Robotics and Automation Magazine, IEEE}, volume = {15}, number = {1}, year = {2008}, pages = {62{\textendash}70}, keywords = {Robotics}, doi = {10.1109/M-RA.2007.914925}, url = {http://dx.doi.org/10.1109/M-RA.2007.914925}, author = {A. Bicchi and A. Danesi and G. Dini and La Porta, S. and L. Pallottino and I. M. Savino and R. Schiavi} } @conference {MSVBB-CDC08, title = {Hybrid system reduction}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2008}, pages = {227 -232}, keywords = {Embedded Control, Robotics}, author = {E. Mazzi and A. Sangiovanni Vincentelli and A. Balluchi and A. Bicchi} } @article {PB08, title = {Hypercubes are minimal controlled invariants for discrete-time linear systems with quantized scalar input}, journal = {Nonlinear Analysis. Hybrid systems}, number = {2}, year = {2008}, pages = {706-720}, abstract = {

Quantized linear systems are a widely studied class of nonlinear dynamics resulting from the control of a linear system through finite inputs. The stabilization problem for these models shall be studied in terms of the so called practical stability notion that essentially consists in confining the trajectories into sufficiently small neighborhoods of the equilibrium (ultimate boundedness) . In this paper, we study the problem of describing the smallest sets into which any feedback can ultimately confine the state, for a given linear single-input system with an assigned finite set of admissible input values (quantization). We show that a controlled invariant set of minimal size is contained in a family of sets (namely, hypercubes in controller-canonical form), previously introduced in [14, 15] . A comparison is presented which quantifies the improvement in tightness of the proposed analysis technique with respect to classical results using quadratic Lyapunov functions.

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and A. Bicchi} } @conference {DPB-CDC08, title = {Left invertibility of discrete systems with finite inputs and quantized output}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2008}, pages = {4687 - 4692}, abstract = {

The aim of this paper is to address left invertibility for dynamical systems with inputs and outputs in discrete sets. We study systems that evolve in discrete time within a continuous state-space. Quantized outputs are generated by the system according to a given partition of the state-space, while inputs are arbitrary sequences of symbols in a finite alphabet, which are associated to specific actions on the system. We restrict to the case of contractive dynamics for fixed inputs. The problem of left invertibility, i.e. recovering an unknown input sequence from the knowledge of the corresponding output string, is addressed using the theory of Iterated Function Systems (IFS), a tool developed for the study of fractals. We show how the IFS naturally associated to a system and the geometric properties of its attractor are linked to the left invertibility property of the system. Our main results are a necessary and sufficient condition for a given system to be left invertible with probability one on the space of inputs (i.e. for almost all input sequences), and necessary and sufficient conditions for left invertibility and uniform left invertibility under some weak additional hypotheses. A few examples are presented to illustrate the application of the proposed method.

}, keywords = {Embedded Control, Robotics}, author = {N. Dubbini and B. Piccoli and A. Bicchi} } @conference {FVB-CDC08Ext, title = {Logical Consensus for Distributed Network Agreement}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2008}, note = {

Extended Version

}, pages = {5250 - 5255}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and E.M. Visibelli and A. Bicchi} } @article {B08, title = {Macchine e Mani: Immagini, Immaginazione e Creazione}, journal = {Letteratura e Arte}, number = {6}, year = {2008}, pages = {13-21}, keywords = {Haptics, Robotics}, author = {A. Bicchi} } @conference {MED08-HTB, title = {Neural network based robust adaptive control for a variable stiffness actuator}, booktitle = {Control and Automation, 16 th Mediterranean Conference on Control and Automation}, year = {2008}, pages = {1028 - 1034}, abstract = {

In this paper we present a robust adaptive controller based on a neural network (NN) for a variable stiffness actuator (VSA). The controller is able to independently set the mechanical stiffness and position at the joint shaft to guarantee robustness with respect to slowly time-varying and unmodeled friction coefficients affecting the dynamics of the actuator. The lumped uncertainties of the VSA including unmodeled dynamics are considered and approximated by a simple NN so that the controlled system is asymptotically stable, and remains effective while process conditions vary. To cope with the reconstruction error of the NN, a sliding mode like additional robust control term is introduced. The proofs for the uniformly ultimately bounded (UUB) and uniform asymptotic (UAS) stabilities for the closed-loop system are provided in detail via Lyapunov theory. Simulation and experimental results are reported in support of both validity and performance of the proposed approach.

}, keywords = {Embedded Control, Robotics}, author = {S. Huh and G. Tonietti and A. Bicchi} } @conference {SBFGB08, title = {Optimal Paths in a Constrained Image Plane for Purely Image-Based Parking}, booktitle = {IROS}, year = {2008}, month = {22-26 Sept}, pages = {1673-1680}, abstract = {

This paper presents a correct solution to the optimal feedback control for a nonholonomic vehicle with limited field-of-view. Previous work on this subject has shown that the search for a shortest path can be limited to simple families of trajectories. We preliminarily provide an extension of the alphabet of optimal control words, to cover some regions of the vehicle plane where the synthesis of turns out to be suboptimal. The main contribution of this paper is an algorithm to translate the optimal synthesis to the image plane, thus enabling a purely image-based optimal control scheme. This allows better performance and increases the robustness of the overall process, avoiding the need of slowly-converging and error-prone parameter estimation algorithms. Simulations and experiments are reported which demonstrate the effectiveness of the proposed technique.

}, keywords = {Robotics}, author = {P Salaris and F. A. W. Belo and D. Fontanelli and L. Greco and A. Bicchi} } @conference {AMC08, title = {Physical Human-Robot Interaction: Dependability, Safety, and Performance}, booktitle = {Proc. 10th Intl. Workshop Advanced Motion Control}, year = {2008}, pages = {9-14}, abstract = {

In this paper we discuss the problem of achieving good performance in accuracy and promptness by a robot manipulator under the condition that safety is guaranteed throughout task execution. Intuitively, while a rigid and powerful structure of the arm would favor its performance, lightweight compliant structures are more suitable for safe operation. The quantitative analysis of the resulting design trade-off between safety and performance has a strong impact on how robot mechanisms and controllers should be designed for human-interactive applications. We discuss few different possible concepts for safely actuating joints, and focus on aspects related to the implementation of the mechanics and control of this new class of robots.

}, keywords = {Embedded Control, Physical Human-Robot Interaction (pHRI), Robotics}, author = {A. Bicchi and M. Bavaro and G. Boccadamo and D. De Carli and R. Filippini and G. Grioli and M. Piccigallo and A. Rosi and R. Schiavi and S. Sen and G. Tonietti} } @conference {MED08-GFB, title = {Robust Almost Sure Stability for Uncertain Stochastically Scheduled Anytime Controllers}, booktitle = {Control and Automation, 16 th Mediterranean Conference on Control and Automation}, year = {2008}, pages = {249 - 254}, abstract = {

In this paper we consider closed loop stability of a number of different software tasks implementing a hierarchy of real-time controllers for a given plant, i.e.

}, keywords = {Robotics}, author = {D. Fontanelli and L. Greco and A. Bicchi} } @article {HB08, title = {The Sense of Touch and its Rendering: Progresses in Haptics Research}, volume = {45/2008}, year = {2008}, publisher = {Springer}, address = {Berlin, Heidelberg}, abstract = {

Preface: It is no coincidence that in many languages, deeply involving emotions and feelings are described as "touching". Touch appears indeed to be the most direct, less intellectually mediated sense. As such, it should be a fundamental ingredient of any system aimed at providing compelling sensations of remote presence. Generation of high-definition haptic feedback will be crucially important for driving a sense of Presence in next generation immersive VR and teleoperation systems. The perspective in which this book is conceived is that of understanding and enabling an experience of presence not limited to "being there", but extended to "being in touch" with the virtual or remote surroundings. Despite of numerous technological advances in this field it appears that the development of fully immersive haptic displays cannot proceed by technological innovations alone but requires a deep understanding and utilization of the psychophysical mechanisms of human haptic perception. On one hand, technological innovations are needed to increase the richness and accuracy of physically generated haptic stimuli. The generation of a one-to-one copy of the real world seems, however, to be unfeasible due to the inherent complexity of the necessary devices and stringent physiological and mechanical constraints. On the other hand, advances in the understanding of the information processing of the multidimensional sense of touch contribute to overcome these fundamental technological constraints. Limitations of the human perceptual system can be exploited to provide a realistic haptic sensation without getting all the physical parameters completely right. Perceptual limitations already helped in the design of advanced visual and auditory displays. This book summarizes main results of the TOUCH-HapSys research project financially supported by the 5th Framework IST Programme of the European Union. It provides an important contribution towards a new generation of high-fidelity haptic display technologies. The uniqueness of this book is its interdisciplinary approach highlighting the field of haptic research from a neuropsychological as well as a technological point of view. It provides readers with recent advances in the study of human haptic (kinesthetic, tactile, temperature) and mul-timodal (visual, auditory, haptic) perception mechanisms and with innovations in the field of haptic display technology. It shows that both lines of research are intimately connected, not only because biological sciences inspire and enable technology improvement, but also because novel devices offer new facilities for the experimental testing of psychophysical hypotheses. This book is structured in two parts: A. Fundamental Psychophysical and Neuropsychological Research and B. Technology and Applications. Chapters in part A. concentrate on the study of the basic mechanisms of touch, involving neurophysiology, psychophysics, and functional mappings in the brain. In-depth study of the psychophysiology of the sense of touch establishes connections between haptic fundamental perception and virtual-reality oriented technology. Part B. addresses new technologies to significantly improve haptic and multimodal feedback systems. These include novel actuator designs, software solutions for haptic rendering, and applications. The two parts are not however separated, and the many connections and synergies between the two complementary domains of research are highlighted in the text. Finally the editors would like to thank all the authors for their valuable contributions to this book. The quality and freshness found in each chapter are due to the excellent work carried out by the authors.

}, keywords = {Haptics, Robotics}, editor = {A. Bicchi and M. Buss and M. Ernst and A. Peer} } @inbook {HB08-1, title = {The Sense of Touch and its Rendering: Progresses in Haptics Research}, series = {Springer Tracts in Advanced Robotics (STAR)}, volume = {45/2008}, year = {2008}, pages = {39 - 60}, publisher = {Springer}, organization = {Springer}, type = {Chapter}, chapter = {The Role of Tactile Flow in Processing Dynamic Haptic Stimuli}, address = {Berlin, Heidelberg}, abstract = {

Dynamic stimuli in visual and tactile sensory modalities share fundamental psychophysical features that can be explained by similar computational models. In vision, information about relative motion between objects and the observer are mainly processed by optic flow, which is a 2D field of velocities associated with variation of brightness patterns in the image plane. It provides important information about cues for region and boundary segmentation, shape recovery, and so on. For instance, radial patterns of optic flow are often used to estimate time before contact with an approaching object. We put forward the hypothesis that a similar behavior can be present in the tactile domain, in which an analogous paradigm to optic flow might exist. Moreover, as optic flow is also invoked to explain several visual illusions, including the well-known "barber-pole" effect and Ouchi

}, keywords = {Haptics, Robotics}, author = {E. P. Scilingo and N. Sgambelluri and A. Bicchi}, editor = {A. Bicchi and M. Buss and M. Ernst and A. Peer} } @inbook {HB08-2, title = {The Sense of Touch and its Rendering: Progresses in Haptics Research}, series = {Springer Tracts in Advanced Robotics (STAR)}, volume = {45/2008}, year = {2008}, pages = {155-178}, publisher = {Springer}, organization = {Springer}, type = {Chapter}, chapter = {Rheological Device}, address = {Berlin, Heidelberg}, abstract = {

In this work we investigate the possibility of mimicking haptic perception by using rheological materials. An analysis of the rheological behaviour of some "smart fluids", such as Electro-rheological Fluids (ERFs) and Magneto-rheological Fluids (MRFs), is provided to design new haptic interfaces capable of reproducing shape and compliance of some virtual objects. Some theoretical design considerations are discussed and supported by magnetic simulations implemented by means of a numerical code. Several prototypes were designed and realized through a progressive enhancement of performance up to a final 3D immersive device. Furthermore, to assess performance a set of psychophysical tests was carried out and experimental results in terms of softness and shape recognition are reported.

}, keywords = {Haptics, Robotics}, author = {N. Sgambelluri and E. P. Scilingo and R. Rizzo and A. Bicchi}, editor = {A. Bicchi and M. Buss and M. Ernst and A. Peer} } @article {VHTRTZGCSSGPSBPDRL08, title = {Sensing Glove for Brain Studies: Design and assessment of its Compatibility for fMRI with a Robust Test}, journal = {IEEE - ASME Transactions on Mechatronics}, volume = {13}, number = {3}, year = {2008}, pages = {345-354}, abstract = {

In this paper, we describe a biomimetic-fabric-based sensing glove that can be used tomonitor hand posture and gesture. Our device is made of a distributed sensor network of piezoresistive conductive elastomers integrated into an elastic fabric. This solution does not affect natural movement and hand gestures, and can be worn for a long time with no discomfort. The glove could be fruitfully employed in behavioral and functional studies with functional MRI (fMRI) during specific tactile or motor tasks. To assess MR compatibility of the system, a statistical test on phantoms is introduced. This test can also be used for testing the compatibility of mechatronic devices designed to produce different stimuli inside the MR environment. We propose a statistical test to evaluate changes in SNR and time-domain standard deviations between image sequences acquired under different experimental conditions. fMRI experiments on subjects wearing the glove are reported. The reproducibility of fMRIresults obtained with andwithout the glove was estimated. A good similarity between the activated regions was found in the two conditions.

}, keywords = {Haptics, Robotics}, author = {N. Vanello and V. Hartwig and M. Tesconi and E. Ricciardi and A. Tognetti and G. Zupone and R. Gassert and D. Chapuis and N. Sgambelluri and E. P. Scilingo and G. Giovannetti and V. Positano and M. F. Santarelli and A. Bicchi and P. Pietrini and D. De Rossi and L. Landini} } @conference {PMB08, title = {Steering a Leader-Follower Team via Linear Consensus}, booktitle = {Hybrid Systems: Computation and Control}, series = {Lecture Notes in Computer Science}, volume = {4981/2008}, year = {2008}, pages = {642-645}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, abstract = {

The paper considers the problem of driving a formation of autonomous mobile agents. The group of mobile devices is described as a leader{\textendash}follower network, where the followers update their position using a simple local consensus procedure, while the leaders, whose positions represent the control inputs of the network, are free to move. We characterize the transient behavior of the network, and solve the containment problem without relying on auxiliary sensors.

}, keywords = {Embedded Control, Robotics}, author = {F. Pasqualetti and S. Martini and A. Bicchi}, editor = {M. Egerstedt and B. Mishra} } @article {BRB07, title = {Tactile flow explains haptic counterparts of common visual illusions}, journal = {Brain Res Bull.}, volume = {75}, number = {6}, year = {2008}, month = {April 15}, pages = {737-741}, abstract = {

Interaction with the external world requires the ability to perceive dynamic changes in complex sensorial input and react promptly. Here we show that perception of dynamic stimuli in the visual and tactile sensory modalities share fundamental psychophysical aspects that can be explained by similar computational models. In vision, optic flow provides information on relative motion between the individual and the content of percept. For instance, radial patterns of optic flow are used to estimate time before contact with an approaching object4. Similarly, in the tactile modality, radial patterns of stimuli provide information on softness of probed objects3. Optic flow is also invoked to explain several visual illusions, including the well-known "barber-pole" effect10. Here we introduce a computational model of tactile flow, which is intimately related to existing models for the visual counterpart. The model accounts for psychophysical aspects of dynamic tactile perception and predicts illusory phenomena in the tactile domain, analogous to the barber-pole effect. When subjects touched translating pads with differently oriented gratings, they perceived a direction of motion that was significantly biased towards the orientation of the gratings. Therefore, these findings indicate that visual and tactile flow share similarities at the psychophysical and computational level and may be intended for similar perceptive goals. Results of this analysis have impact on the engineering of better haptic and multimodal interfaces for human-computer interaction.

}, keywords = {Haptics, Robotics}, author = {A. Bicchi and E. P. Scilingo and E. Ricciardi and P. Pietrini} } @conference {BFDS08, title = {Tolerating Malicious Monitors in Detecting Misbehaving Robots}, booktitle = {IEEE International Workshop on Safety, Security, and Rescue Robotics}, year = {2008}, pages = {108 - 114}, address = {Tohoku University Aobayama Campus, Sendai, Japan}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and A. Bicchi and G. Dini and I. M. Savino} } @article {FSB08, title = {Toward Soft Robot you can Depend on}, journal = {IEEE Robotics and Automation Magazine}, volume = {15}, number = {3}, year = {2008}, pages = {31 - 41}, keywords = {Embedded Control, Robotics}, author = {R. Filippini and S. Sen and A. Bicchi} } @conference {DFB, title = {Visual Servoing on Image Maps}, booktitle = {Experimental Robotics}, series = {Springer Tracts in Advanced Robotics (STAR)}, volume = {39}, year = {2008}, note = {

proceedings of the 2006 symposium of experimental robotics

}, pages = {277 - 286}, publisher = {Springer Berlin / Heidelberg}, organization = {Springer Berlin / Heidelberg}, keywords = {Robotics}, author = {A. Danesi and D. Fontanelli and A. Bicchi} } @conference {iser08, title = {Visual SLAM for Servoing for Appearance Based Topological Maps}, booktitle = {Proc. Ints. Symp. Experimental Robotics}, series = {Experimental Robotics}, volume = {39/2008}, year = {2008}, pages = {277-286}, keywords = {Robotics}, author = {P Salaris and F. A. W. Belo and D. Fontanelli and A. Bicchi}, editor = {Springer-Verlag} } @conference {schiavi2008icra, title = {VSA-II: A Novel Prototype of Variable Stiffness Actuator for Safe and Performing Robots Interacting with Humans}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2008}, pages = {2171 - 2176}, abstract = {

This paper presents design and performance of a novel joint based actuator for a robot run by variable stiffness actuation, meant for systems physically interacting with humans. This new actuator prototype (VSA-II) is developed as an improvement over our previously developed one reported in [9], where an optimal mechanical-control co-design principle established in [7] is followed as well. While the first version was built in a way to demonstrate effectiveness of variable impedance actuation (VIA), it had limitations in torque capacities, life cycle and implementability in a real robot. VSA-II overcomes the problem of implementability with higher capacities and robustness in design for longer life. The paper discusses design and stiffness behaviour of VSA-II in theory and experiments. A comparison of stiffness characteristics between the two actuator is discussed, highlighting the advantages of the new design. A simple, but effective PD scheme is employed to independently control joint-stiffness and joint-position of a 1-link arm. Finally, results from performed impact tests of 1- link arm are reported, showing the effectiveness of stiffness variation in controlling value of a safety metric.

}, keywords = {Robotics}, author = {R. Schiavi and G. Grioli and S. Sen and A. Bicchi} } @conference {GFB07, title = {Almost Sure Stability of Anytime Controllers via Stochastic Scheduling}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2007}, month = {December}, pages = {5640-5645}, abstract = {

In this paper we consider scheduling the execution of a number of different software tasks implementing a hierarchy of real-time controllers for a given plant. Controllers are considered to be given and ordered according to a measure of the performance they provide. Software tasks implementing higher-performance controllers are assumed to require a larger worst-case execution time. Control tasks are to be scheduled within given availability limits on execution time, which change stochastically in time. The ensuing switching system is prone to instability, unless a very conservative policy is enforced of always using the simplest, least performant controller. The presented method allows to condition the stochastic scheduling of control tasks so as to obtain a better exploitation of computing capabilities, while guaranteeing almost sure stability of the resulting switching system.

}, keywords = {Embedded Control, Robotics}, author = {L. Greco and D. Fontanelli and A. Bicchi} } @article {DSSDLB07, title = {An atlas of physical human-robot interaction}, journal = {Mechanism and Machine Theory}, volume = {43}, number = {3}, year = {2007}, pages = {253-270}, abstract = {

A broad spectrum of issues have to be addressed in order to tackle the problem of a safe and dependable physical Human-Robot Interaction (pHRI). In the immediate future, metrics related to safety and dependability have to be found in order to successfully introduce robots in everyday enviornments. While there are certainly also {\textquoteleft}{\textquoteleft}cognitive

}, keywords = {Physical Human-Robot Interaction (pHRI), Robotics}, author = {De Santis, A and B. Siciliano and A.De Luca and A. Bicchi} } @conference {filippini2007cda, title = {A Comparative Dependability Analysis of Antagonistic Actuation Arrangements for Enhanced Robotic Safety}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2007}, pages = {4349{\textendash}4354}, abstract = {In this paper we introduce an analysis of dependability of an elementary yet critical component of robotic systems designed to operate in environments shared with humans, i.e. the joint-level actuation system. We consider robot joints that implement the Variable Impedance Actuation (VIA) paradigm. The VIA has been demonstrated to be an effective mean to achieve high performance while constantly keeping injury risks to humans by accidental impacts below a given threshold. The paper describe possible implementations of the VIA concept which use the Antagonistic Actuation (AA) in three different arrangements. This study follows a previously reported paper dealing with safety. Here a detailed comparative dependability and performability analysis in front of possible specific failure modes is conducted, whose results provide additional and useful guidelines for design of safe and dependable actuation systems for physical human-robot interaction. }, keywords = {Robotics}, author = {R. Filippini and S. Sen and G. Tonietti and A. Bicchi} } @conference {BDSP:ECC07, title = {A Component-Based Approach to Localization and Collision Avoidance for Mobile Multi-Agent Systems}, booktitle = {Proc. European Control Conference (ECC)}, year = {2007}, month = {July}, pages = {4285-4292}, abstract = {

In the RUNES project a disaster relief tunnel scenario is being developed in which mobile robots are used to restore the radio network connectivity in a stationary sensor network. A component-based software development approach has been adopted. Two components are described in this paper. A localization component that uses ultrasound and dead reckoning to decide the robot positions and a collision avoidance component that ensures that the robots do not collide with each other.

}, keywords = {Embedded Control, Robotics}, author = {P. Alriksson and J. Nordh and K -E Arz{\'e}n and A. Bicchi and A. Danesi and R. Schiavi and L. Pallottino} } @article {arz+07ejc, title = {A component-based approach to the design of networked control systems}, journal = {European Journal of Control}, volume = {13}, number = {2{\textendash}3}, year = {2007}, note = {

Invited paper

}, pages = {261-279}, abstract = {

Component-based techniques revolve around composable, reusable software objects that shield the application level software from the details of the hardware and lowlevel software implementation and vice versa. Components provide many benefits that have led to their wide adoption in software and middleware developed for embedded systems: They are well-defined entities that can be replaced without affecting the rest of the systems, they can be developed and tested separately and integrated later, and they are reusable. Clearly such features are important for the design of large-scale complex systems more generally, beyond software architectures. We propose the use of a component approach to address embedded control problems. We outline a general componentbased framework to embedded control and show how it can be instantiated in specific problems that arise in the control over/of sensor networks. Building on the middleware component framework developed under the European project RUNES, we develop a number of control-oriented components necessary for the implementation of control applications and design their integration. The paper provides the overview of the approach, discusses a real life application where the approach has been tested and outlines a number of specific control problems that arise in this application.

}, keywords = {Embedded Control, Robotics}, author = {K -E Arz{\'e}n and A. Bicchi and G. Dini and S. Hailes and K. H. Johansson and J. Lygeros and A. Tzes} } @article {PSFB06-TRO, title = {Decentralized cooperative policy for conflict resolution in multi-vehicle systems}, journal = {IEEE Trans. on Robotics}, volume = {23}, number = {6}, year = {2007}, pages = {1170-1183}, abstract = {

In this paper we propose a novel policy for steering multiple vehicles between assigned independent start and goal configurations and ensuring collision avoidance. The policy rests on the assumption that agents are all cooperating by implementing the same traffic rules. However, the policy is completely decentralized, as each agent decides its own motion by applying those rules only on locally available information, and totally scalable, in the sense that the amount of information processed by each agent and the computational complexity of the algorithms are not increasing with the number of agents in the scenario. The proposed policy applies to systems in which new vehicle may enter the scene and start interacting with existing ones at any time, while others may leave. Under mild conditions on the initial configurations, the policy is shown to be safe, i.e. to guarantee collision avoidance throughout the system evolution. In the paper, conditions are discussed on the desired configurations of agents under which the ultimate convergence of all vehicles to their goals can also be guaranteed. To show that such conditions are actually necessary and sufficient, which turns out to be a challenging liveness verification problem for a complex hybrid automaton, we employ a probabilistic verification method. The paper finally reports on simulations for systems of several tens of vehicles, and with some experimental implementation showing the practicality of the approach.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and V. G. Scordio and E. Frazzoli and A. Bicchi} } @conference {FVPDB:CDC07, title = {Decentralized Intrusion Detection for Secure Cooperative Multi-Agent Systems}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2007}, pages = {1553-1558}, abstract = {

In this paper we address the problem of detecting faulty behaviors of cooperative mobile agents. A novel decentralized and scalable architecture that can be adopted to realize a monitor of the agents

}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and G. Valenti and L. Pallottino and G. Dini and A. Bicchi} } @conference {PBB07, title = {Distributed intrusion detection for secure consensus computations}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2007}, month = {December}, pages = {5594-5599}, abstract = {

This paper focuses on trustworthy computation systems and proposes a novel intrusion detection scheme for averaging networks with misbehaving nodes. This prototypical control problem is relevant in network security applications. The objective is for each node to detect and isolate the misbehaving nodes using only the information flow adopted by standard averaging protocols. We focus on the single misbehaving node problem. Our technical approach is based on the theory of Unknown Input Observability. First, we give necessary and sufficient conditions for the misbehavior to be observable and for the identity of the faulty node to be detectable. Second, we design a distributed unknown input estimator, and we characterize its convergence rate in the

}, keywords = {Embedded Control, Robotics}, author = {F. Pasqualetti and A. Bicchi and F. Bullo} } @conference {PB06, title = {A Dynamic Programming Approach to Optimal Planning for Vehicles with Trailers}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2007}, pages = {3098 - 3103}, abstract = {

In this paper we deal with the optimal feedback synthesis problem for robotic vehicles with trailers which can be modeled by differential equations in chained-form. With respect to classical methods for numerical evolution of optimal feedback synthesis via Dynamic Programming which are based on both input and state discretization, our method exploits the lattice structure naturally imposed on the reachable set by input quantization. A generalized Dijkstra algorithm can be used to obtain optimal feedback control laws, for chained-form vehicles with n-trailers, in an effective way.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and A. Bicchi} } @conference {LJB07, title = {An experimental study of exploiting multipath fading for robot communications}, booktitle = {Proceedings of Robotics: Science and Systems}, year = {2007}, month = {June}, address = {Atlanta, GA, USA}, abstract = {

A simple approach for mobile robots to exploit multipath fading in order to improve received radio signal strength (RSS), is presented. The strategy is to sample the RSS at discrete points, without deviating too far from the desired position. We first solve the problem of how many samples are needed for given communications performance and how they should be spaced. Second, we propose a circular and a grid trajectory for sampling and give lower bounds on how many samples they will yield. Third, we estimate the parameters of our strategy from measurements. Finally we demonstrate the validity of our analysis through experiments.

}, keywords = {Robotics}, author = {M. Lindh{\`e} and K. H. Johansson and A. Bicchi} } @conference {BBMSS-07, title = {Hybrid Multi-rate Control of the Common-Rail}, booktitle = {European Control Conference}, year = {2007}, pages = {54-61}, abstract = {

We present an industrial case study in automotive control of significant complexity: the new common-rail fuel- injection system for Diesel engines developed by Magneti Marelli Powertrain. In this system, an inlet metering valve, inserted before the High Pressure (HP) pump, regulates the fuel flow that supplies the common rail according to the engine operating point (e.g. engine speed and torque). The standard approach to controller design adopted in the automotive in- dustry is based on mean-value models of the plant. However, the fuel injection system exhibits complex discrete-continuous interactions, due to the slow time-varying frequency of the HP pump cycles and the fast sampling frequency of sensing and actuation. Hence, a hybrid approach to controller design is very promising. In this paper, we present the synthesis of a hybrid multi-rate controller for a Magneti Marelli Powertrain common-rail fuel- injection system for four-cylinder multi-jet engines. Controller design is based on a hybrid model of the injection system. The resulting hybrid controller performs significantly better then previous controllers developed in the company on the basis of mean-value models of the plant.

}, keywords = {Embedded Control, Robotics}, author = {A. Balluchi and A. Bicchi and E. Mazzi and A. Sangiovanni-Vincentelli and G. Serra} } @conference {FVPDB:CASE07, title = {Local Monitor Implementation for Decentralized Intrusion Detection in Secure Multi-Agent Systems}, booktitle = {3rd IEEE Conference on Automation Science and Engineering}, year = {2007}, pages = {454{\textendash}459}, abstract = {

This paper focuses on the detection of misbehaving agents within a group of mobile robots. A novel approach to automatically synthesize a decentralized Intrusion Detection System (IDS) as well as an efficient implementation of local monitors are presented. In our scenario, agents perform possibly different independent tasks, but cooperate to guarantee the entire system

}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and G. Valenti and L. Pallottino and G. Dini and A. Bicchi} } @conference {PSFB07-ACC, title = {Probabilistic verification of decentralized multi-agent control strategies: a case study in conflict avoidance}, booktitle = {American Control Conference (ACC)}, year = {2007}, pages = {170-175}, abstract = {

Many challenging verification problems arise from complex hybrid automata that model decentralized control systems. As an example, we will consider decentralized policies that steer multiple vehicles in a shared environment: properties of safety and liveness, such as collision avoidance and ultimate convergence of all vehicles to their goals, must be verified. To formally verify the behavior of proposed policies, it is desired to identify the broadest class of start and goal configurations, such that safety and liveness would be guaranteed. Simple conditions are proposed to identify such a class: ideally, a formal proof that such conditions are necessary and sufficient for safety and liveness is requested. Unfortunately, in decentralized control frameworks classical approaches are difficult to apply. Hence, probabilistic verification method can be applied to quantify the accuracy and the confidence of the veridicity of the desired predicate. The probabilistic verification method is applied to a recently proposed cooperative and completely decentralized collision avoidance policy for non-holonomic vehicles.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and A. Bicchi and E. Frazzoli} } @article {PB07-TAC, title = {On the Stabilization of Linear Systems Under Assigned I/O Quantization}, journal = {IEEE Transactions on Automatic Control}, volume = {52}, number = {10}, year = {2007}, pages = {1994-2000}, abstract = {

This paper is concerned with the stabilization of discrete-time linear systems with quantization of the input and output spaces, i.e., when available values of inputs and outputs are discrete. Unlike most of the existing literature, we assume that how the input and output spaces are quantized is a datum of the problem, rather than a degree of freedom in design. Our focus is hence on the existence and synthesis of symbolic feedback controllers, mapping output words into the input alphabet, to steer a quantized I/O system to within small invariant neighborhoods of the equilibrium starting from large attraction basins. We provide a detailed analysis of the practical stabilizability of systems in terms of the size of hypercubes bounding the initial conditions, the state transient and the steady state evolution. We also provide an explicit construction of a practically stabilizing controller for the quantized I/O case.

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and A. Bicchi} } @conference {GFBP-07, title = {Steering Dynamical Systems with Finite Plans and Limited Path Length}, booktitle = {European Control Conference}, year = {2007}, pages = {4686-4690}, abstract = {

Complex dynamical systems can be steered by using symbolic input plans. These plans must have a finite descriptive length, and can be expressed by means of words chosen in an alphabet of symbols. In this way, such plans can be sent through a limited capacity channel to a remote system, where they are decoded in suitable control actions. The choice of this symbols is essential to efficiently encode steering plans. To this aim, in this paper, we state the problem of finding symbols maximizing the interval of points reachable by the system along paths with constrained length. We focus on the problem with two symbols, and compare the results with those produced by plans not accounting for the length constraint. Moreover, the behavior of a simple helicopter, steered by both kinds of plans, has been simulated, in order to illustrate the power of the overall control system, and to emphasize the improvements introduced by the new plans.

}, keywords = {Embedded Control, Robotics}, author = {L. Greco and A. Fagiolini and A. Bicchi and B. Piccoli} } @article {BBEFKP06, title = {Symbolic Planning and Control of Robot Motion: Finding the Missing Pieces of Current Methods and Ideas}, journal = {Robotics and Automation Magazine}, volume = {14}, number = {1}, year = {2007}, pages = {61-70}, abstract = {

Approaches to robot motion planning and control that involve tools such as automata, languages, temporal logics, and grammars, have been recently termed "symbolic." In this article, we review some existing results, discuss their relevance and applicability, and outline some of the main open questions and challenges in the area.

}, keywords = {Embedded Control, Robotics}, author = {C. Belta and A. Bicchi and M. Egerstedt and E. Frazzoli and E. Klavins and G. J. Pappas} } @conference {FSB07, title = {Variable Impedance Actuations for Physical Human Cooperating Robots: a Comparative Analysis of Performance, Safety and Dependability}, booktitle = {Proc. IARP-IEEE/RAS-EURON Workshop on Technical Challenges for Dependable Robots in Human Environments.}, year = {2007}, month = {April}, abstract = {

An antagonistic actuation with variable stiffness is proposed for ensuring safety and performance in human friendly robotic applications. Various arrangements are analysed with respect to performance, safety and dependability. The results are expected to provide useful guidelines for choosing an actuation mechanism and its implementation for human-robot interactive applications.

}, keywords = {Robotics}, author = {R. Filippini and S. Sen and A. Bicchi} } @conference {FontanelliVGCB06, title = {Adaptive non Linear Control of Dynamic Mobile Robots with Parameters Uncertainty}, booktitle = {Int. IFAC Symp. on Robot Control}, year = {2006}, month = {September}, address = {Bologna, Italy}, abstract = {

Research of a modular stabilizing control law for uncertain, nonholonomic mobile systems with actuators limitation has been investigated. Modular design allows the definition of a stabilizing control law for the kinematic model. The presence of uncertainties in the actuators parameters or in the vehicle dynamics has been treated both adding suitable components to the Lyapunov function and using parameters adaptation laws (e.g. adaptive control and backstepping techniques). Simulations are reported for the set point stabilization of a unicycle like vehicle showing the feasibility of the proposed approach. Torque limitations for a unicycle like vehicle has been investigated using backstepping techniques for the vehicle tracking problem. Simulations are reported.

}, keywords = {Embedded Control, Robotics}, author = {D. Fontanelli and R. Viviani and L. Greco and A. Caiti and A. Bicchi} } @conference {FTB06, title = {Casting Robotic end-effectors to reach far objects in space and planetary missions}, booktitle = {Proc. of the 9th ESA Workshop on Advanced Space Technologies for Robotics and Automation}, year = {2006}, pages = {28-30}, keywords = {Robotics}, author = {A. Fagiolini and A. Torelli and A. Bicchi} } @inbook {B06, title = {Controllo, Teoria del}, booktitle = {Enciclopedia Italiana di Scienze, Lettere ed Arti}, year = {2006}, publisher = {Istituto della Enciclopedia Italiana {\textquoteleft}{\textquoteleft}G. Treccani{\textquoteright}{\textquoteright}}, organization = {Istituto della Enciclopedia Italiana {\textquoteleft}{\textquoteleft}G. Treccani{\textquoteright}{\textquoteright}}, edition = {XXI Secolo {\textendash} Aggiornamento}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi} } @conference {PSFB-MTNS06, title = {Decentralized and scalable conflict resolution strategy for multi-agents systems}, booktitle = {Int. Symp. on Mathematical Theory of Networks and Systems}, year = {2006}, abstract = {

A decentralized cooperative collision avoidance control policy for planar vehicle recently proposed is herein considered. Given some simple conditions on initial configurations of agents, the policy is known to ensure safety (i.e., collision avoidance) for an arbitrarily large number of vehicles. The method is highly scalable, and effective solutions can be obtained for several tens of autonomous agents. On the other hand, the liveness property of the policy, i.e. the capability of negotiating a solution in finite time, is not yet completely understood. First a 3D workspace extension is proposed. Furthermore, based on a condition on target configuration previously proposed, some general results on the liveness property are reported. Finally, qualitative evaluations on the strategy and on the proposed target sparsity condition are pointed out.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and V. G. Scordio and E. Frazzoli and A. Bicchi} } @conference {CACSD06, title = {On the Design and Control of Wireless Networked Embedded Systems}, booktitle = {Int. Conf. on Computer Aided Control System Design - CACSD{\textquoteright}06}, year = {2006}, pages = {440-445}, publisher = {IEEE}, organization = {IEEE}, abstract = {

Wireless networked embedded systems are becoming increasingly important in a wide area of technical fields. In this tutorial paper we present recent results on design and control of these systems developed within the project Reconfigurable Ubiquitous Networked Embedded Systems (RUNES), which is an European Integrated Project with the aim to control complexity in networked embedded systems by developing robust and scalable middleware systems. New components for control under varying network conditions are discussed for the RUNES architecture. The complexity of the closed-loop system is increased due to the coupling with the disturbances introduced by the communication system. The network may introduce additional delays, jitter, data rate limitations, packet losses etc. Experimental work on integration test beds that demonstrates these results is shown together with motivating links to the RUNES disaster relief tunnel scenario.

}, keywords = {Embedded Control, Robotics}, author = {K -E Arz{\'e}n and A. Bicchi and S. Hailes and K. H. Johansson and J. Lygeros} } @article {BBMP-TAC06, title = {Feedback Encoding for Efficient Symbolic Control of Dynamical Systems}, journal = {IEEE Trans. on Automatic Control}, volume = {51}, number = {6}, year = {2006}, pages = {1-16}, abstract = {

The problem of efficiently steering dynamical systems by generating finite input plans is considered. Finite plans are finite{\textendash}length words constructed on a finite alphabet of input symbols, which could be e.g. transmitted through a limited capacity channel to a remote system, where they can be decoded in suitable control actions. Efficiency is considered in terms of the computational complexity of plans, and in terms of their description length (in number of bits). We show that, by suitable choice of the control encoding, finite plans can be efficiently built for a wide class of dynamical systems, computing arbitrarily close approximations of a desired equilibrium in polynomial time. The paper also investigates how the efficiency of planning is affected by the choice of inputs, and provides some results as to optimal performance in terms of accuracy and range.

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and A. Marigo and B. Piccoli} } @conference {BBMSS06, title = {Hybrid Modelling and Control of the Common Rail Injection System}, booktitle = {Hybrid Systems: Computation and Control}, series = {Lecture Notes in Computer Science}, volume = {3927 / 2006}, year = {2006}, pages = {79-92}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, abstract = {

We present an industrial case study in automotive control of significant complexity: the new common rail fuel injection system for Diesel engines, currently under production by Magneti Marelli Powertrain. In this system, a flow-rate valve, introduced before the High Pressure (HP) pump, regulates the fuel flow that supplies the common rail according to the engine operating point. The standard approach followed in automotive control is to use a mean-value model for the plant and to develop a controller based on this model. In this particular case, this approach does not provide a satisfactory solution as the discrete-continuous interactions in the fuel injection system, due to the slow time-varying frequency of the HP pump cycles and the fast sampling frequency of sensing and actuation, play a fundamental role. We present a design approach based on a hybrid model of the Magneti Marelli Powertrain common-rail fuel-injection system for four-cylinder multi-jet engines and a hybrid approach to the design of a rail pressure controller. The hybrid controller is compared with a classical mean-value based approach to automotive control design whereby the quality of the hybrid solution is demonstrated.

}, keywords = {Embedded Control, Robotics}, author = {A. Balluchi and A. Bicchi and E. Mazzi and A. Sangiovanni Vincentelli and G. Serra}, editor = {J. Hespanha and A. Tiwari} } @conference {BMP06-HSCC, title = {Improving efficiency of finite plans by optimal choice of input sets}, booktitle = {Hybrid Systems: Computation and Control}, series = {Lecture Notes in Computer Science}, volume = {3927 / 2006}, year = {2006}, pages = {108-122}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, abstract = {

Finite plans proved to be an efficient method to steer complex control systems via feedback quantization. Such finite plans can be encoded by finite{\textendash}length words constructed on suitable alphabets, thus permitting transmission on limited capacity channels. In particular flat systems can be steered computing arbitrarily close approximations of a desired equilibrium in polynomial time. The paper investigates how the efficiency of planning is affected by the choice of inputs, and provides some results as to optimal performance in terms of accuracy and range. Efficiency is here measured in terms of computational complexity and description length (in number of bits) of finite plans.

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and A. Marigo and B. Piccoli}, editor = {J. Hespanha and A. Tiwari} } @inbook {ISER04, title = {Optimal Mechanical/Control Design for Safe and Fast Robotics}, booktitle = {Experimental Robotics IX: The 9th International Symposium on Experimental Robotics}, series = {Springer Tracts in Advanced Robotics}, volume = {21}, year = {2006}, pages = {311 - 320}, publisher = {Springer Berlin / Heidelberg}, organization = {Springer Berlin / Heidelberg}, abstract = {

The problem to ensure safety of performant robot arms during task execution was previously investigated by authors. The problem can be approached by studying an optimal control policy, the "Safe Brachistocrone", whose solutions are joint impedance trajectories coordinated with desired joint velocities. Transmission stiffness is chosen so as to achieve minimum-time task execution for the robot, while guaranteeing an intrinsic safety level in case of an unexpected collision between a link of the arm and a human operator. In this paper we extend this approach to more general classes of robot actuation systems, whereby other impedance parameters beside stiffness (such as e.g. joint damping and/or plasticity) can vary. We report on a rather extensive experimental campaign validating the proposed approach.

}, keywords = {Physical Human-Robot Interaction (pHRI), Robotics}, author = {G. Tonietti and R. Schiavi and A. Bicchi}, editor = {Marcelo H. Ang, Oussama Khatib} } @inbook {BSSTB06, title = {Optimization and Fail-Safety Analysis of Antagonistic Actuation for pHRI}, booktitle = {European Robotics Symposium 2006}, series = {Springer Tracts in Advanced Robotics}, volume = {22}, year = {2006}, pages = {109 - 118}, publisher = {Springer Berlin / Heidelberg}, organization = {Springer Berlin / Heidelberg}, abstract = {

In this paper we consider some questions in the design of actuators for physical Human-Robot Interaction (pHRI) under strict safety requirements in all circumstances, including unexpected impacts and HW/SW failures. We present the design and optimization of agonistic-antagonistic actuation systems realizing the concept of variable impedance actuation (VIA). With respect to previous results in the literature, in this paper we consider a realistic physical model of antagonistic systems, and include the analysis of the effects of cross-coupling between actuators. We show that antagonistic systems compare well with other possible approaches in terms of the achievable performance while guaranteeing limited risks of impacts. Antagonistic actuation systems however are more complex in both hardware and software than other schemes. Issues are therefore raised, as to fault tolerance and fail safety of different actuation schemes. In this paper, we analyze these issues and show that the antagonistic implementation of the VIA concept fares very well under these regards also.

}, keywords = {Physical Human-Robot Interaction (pHRI), Robotics}, author = {G. Boccadamo and R. Schiavi and S. Sen and G. Tonietti and A. Bicchi}, editor = {H. Christensen} } @conference {PB06, title = {Practical stabilization of LTI SISO systems under assigned Input and Output quantization}, year = {2006}, note = {

ADHS{\textquoteright}06

}, month = {July}, pages = {353-358}, abstract = {

This work is concerned with the practical stabilization of discrete{\textendash}time SISO linear systems under assigned quantization of the input and output spaces. A controller is designed which guarantees effective practical stability properties. Unlike most of the existing literature, quantization is supposed to be a problem datum rather than a degree of freedom in design. Moreover, in the framework of control under assigned quantization, results are concerned with state quantization only and do not include the quantized output feedback case considered here. While standard stability analysis techniques are based on Lyapunov theory and invariant ellipsoids, our study of the closed loop dynamics involves a particularly suitable family of sets, which are hypercubes in controller form coordinates.

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and A. Bicchi} } @conference {PSFB06, title = {Probabilistic verification of a decentralized policy for conflict resolution in multi-agent systems}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2006}, note = {

Correct version

}, pages = {2448-2453}, abstract = {

In this paper, we consider a decentralized cooperative control policy proposed recently for steering multiple non-holonomic vehicles between assigned start and goal configurations while avoiding collisions. The policy is known to ensure safety (i.e., collision avoidance) for an arbitrarily large number of vehicles, if initial configurations satisfy certain conditions. The method is highly scalable, and effective solutions can be obtained for several tens of autonomous agents. On the other hand, the liveness property of the policy, i.e. the capability of negotiating a solution in finite time, is not yet completely understood. In this paper, we introduce a condition on the final vehicle configurations, which we conjecture to be sufficient for guaranteeing liveness. Because of the overwhelming complexity of proving the sufficiency of such condition, we assess the correctness of the conjecture in probability through the analysis of the results of a large number of randomized experiments.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and V. G. Scordio and E. Frazzoli and A. Bicchi} } @conference {PHRI06, title = {Safe and Dependable Physical Human-Robot Interaction in Anthropic Domains: State of the Art and Challenges}, booktitle = {Proc. IROS{\textquoteright}06 Workshop on pHRI - Physical Human-Robot Interaction in Anthropic Domains}, year = {2006}, publisher = {IEEE}, organization = {IEEE}, keywords = {Robotics}, author = {R. Alami and A Albu-Schaeffer and A. Bicchi and R. Bischoff and R. Chatila and A. De Luca and De Santis, A and G. Giralt and J. Guiochet and G. Hirzinger and F. Ingrand and V. Lippiello and R. Mattone and D. Powell and S. Sen and B. Siciliano and G. Tonietti and L. Villani}, editor = {A. Bicchi and A. De Luca} } @conference {DFPSSDB06, title = {A scalable platform for safe and secure decentralized traffic management of multiagent mobile systems}, booktitle = {ACM Workshop on Real-World Wireless Sensor Networks}, year = {2006}, abstract = {

In this paper we describe the application of wireless sensor networking techniques to address the realization of a safe and secure decentralized traffic management system. We consider systems of many heterogeneous autonomous vehicles moving in a shared environment. Each vehicle is assumed to have different and possibly unspecified tasks, but they cooperate to avoid collisions. We are interested in designing a scalable architecture capable of accommodating a very large and dynamically changing number of vehicles, guaranteeing their safety (i.e., collision avoidance), the achievement of their goals, and security against potential adversaries. By properly distributing and revoking cryptographic keys we are able to protect communications from an external adversary as well as to detect non-cooperative, possibly malicious vehicles and trigger suitable countermeasures. In our architecture, scalability is obtained by decentralization, i.e. each vehicle is regarded as an autonomous agent capable of processing information concerning its own state and the state of only a fixed, small number of {\textquoteleft}{\textquoteleft}neighboring{\textquoteright}{\textquoteright} agents. Ad-hoc wireless sensor networks are employed to provide support for this architecture.

}, keywords = {Embedded Control, Robotics}, author = {A. Danesi and A. Fagiolini and I. Savino and L. Pallottino and R. Schiavi and G. Dini and A. Bicchi} } @conference {DSSBG06, title = {Security and Advanced Control Issues in a Robotic Platform for Monitoring and Relief}, booktitle = {Proc. of EWSN 2006 February 13-15, ETH Zurich}, year = {2006}, abstract = {

This paper provides an architectural overview and a first implementation of an heterogeneous agent network composed by mobile robots of di

}, keywords = {Embedded Control, Robotics}, author = {A. Danesi and I. M. Savino and R. Schiavi and A. Bicchi and G. Dini} } @conference {FGBPM06, title = {Symbolic Control for Underactuated Differentially Flat Systems}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2006}, pages = {1649-1654}, abstract = {

In this paper we address the problem of generating input plans to steer complex dynamical systems in an obstacle-free environment. Plans considered admit a finite description length and are constructed by words on an alphabet of input symbols, which could be e.g. transmitted through a limited capacity channel to a remote system, where they can be decoded in suitable control actions. We show that, by suitable choice of the control encoding, finite plans can be efficiently built for a wide class of dynamical systems, computing arbitrarily close approximations of a desired equilibrium in polynomial time. Moreover, we illustrate by simulations the power of the proposed method, solving the steering problem for two examples in the class of underactuated systems, which have attracted wide attention in the recent literature.

}, keywords = {Embedded Control, Robotics}, author = {A. Fagiolini and L. Greco and A. Bicchi and B. Piccoli and A. Marigo} } @booklet {BCFGV05, title = {Adaptive nonlinear control of dynamic mobile robots with parameters uncertainty}, year = {2005}, publisher = {Dipartimento di Sistemi Elettrici e Automazione, Universit\à di Pisa}, abstract = {

Research of a modular stabilizing control law for uncertain, nonholonomic mobile systems with actuators limitation has been investigated. Modular design allows the definition of a stabilizing control law for the kinematic model. The presence of uncertainties in the actuators parameters or in the vehicle dynamics has been treated both adding suitable components to the Lyapunov function and using parameters adaptation laws (e.g. adaptive control and backstepping techniques). Simulations are reported for the set point stabilization of a unicycle like vehicle showing the feasibility of the proposed approach. Torque limitations for a unicycle like vehicle has been investigated using backstepping techniques for the vehicle tracking problem. Simulations are reported.

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and A. Caiti and D. Fontanelli and L. Greco and R. Viviani} } @article {PB04-rendi, title = {Control synthesis for practical stabilization of quantized linear systems}, journal = {Rend. Sem. Mat. Univ. Pol. Torino, Control Theory and Stabil., I}, volume = {63}, number = {4}, year = {2005}, pages = {397{\textendash}410}, abstract = {

In this work we face the stability problem for quantized control systems (QCS). A discrete{\textendash}time single{\textendash}input linear model is considered and, motivated by technological applications, we assume that a uniform quantization of the control set is a priori fixed. As it is well known, for QCS only practical stability properties can be achieved, therefore we focus on the existence and construction of quantized controllers capable of steering a system to within invariant neighborhoods of the equilibrium. The main contribution of the paper consists in a theorem which provides a condition for the practical stabilization in a fixed number of steps: not only the result is interesting in itself, but also it enables to construct a family of stabilizing controllers by means of Model Predictive Control (MPC) techniques. In the last part of the paper some results on the characterization of controlled{\textendash}invariant sets are reviewed and a lower bound on the size of invariant sets is provided.

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and A. Bicchi} } @conference {PSFB05, title = {Decentralized Cooperative Conflict Resolution for Multiple Nonholonomic Vehicles}, booktitle = {Proc. AIAA COnf. on Guidance, Navigation and Control}, year = {2005}, abstract = {

In this paper, we consider the problem of collision-free motion planning for multiple nonholonomic planar vehicles. Each vehicle is capable of moving at constant speed along paths with bounded curvature, and is aware of the position and heading of other vehicles within a certain sensing radius. No other information exchange is required between vehicles. We propose a spatially decentralized, cooperative hybrid control policy that ensures safety for arbitrary numbers of vehicles. Furthermore, we show that under certain conditions, the policy avoids dead- and livelock, and eventually all vehicles reach their intended targets. Simulations and experimental results are presented and discussed.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and V. G. Scordio and E. Frazzoli and A. Bicchi} } @conference {TSB05, title = {Design and Control of a Variable Stiffness Actuator for Safe and Fast Physical Human/Robot Interaction}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2005}, pages = {528-533}, abstract = {

This paper is concerned with the design and control of actuators for machines and robots physically interacting with humans. According to criteria established in our previous work on mechanical-control co-design for intrinsically safe, yet performant machines, we pursue the Variable Impedance Actuation (VIA) approach, purporting actuators that can control in real-time both the reference position and the mechanical impedance of the moving parts in the machine. In this paper we describe an implementation of such concepts, consisting of a novel electromechanical Variable Stiffness Actuation (VSA) motor. The design and the functioning principle of the VSA are reported, along with the analysis of its dynamic behavior. A novel scheme for feedback control of this device is presented, along with experimental results showing performance and safety of a one-link arm actuated by the VSA motor.

}, keywords = {Robotics}, author = {G. Tonietti and R. Schiavi and A. Bicchi} } @conference {LSFD-06, title = {Flusso tattile ed illusione sensoriale}, booktitle = {SINC, Congresso nazionale della Societ}, year = {2005}, month = {May}, pages = {245-249}, address = {Roma, Italy}, keywords = {Haptics, Robotics}, author = {A. Bicchi and E. P. Scilingo} } @conference {BBCCCCPT05, title = {From tele-laboratory to e-learning in automation curricula at the university of Pisa}, booktitle = {Proc. IFAC World Congress}, year = {2005}, abstract = {

The design and development of computational infrastructures supporting existing tele-laboratory experiences in the field of automation and robotics are described. The goal of the activity is to provide a proper e-learning environment in which remote laboratory experiences are integrated in a coherent way. The addition of e-learning features, as self-assessment and progress monitoring tools, asynchronous tutor interaction, authentication, evaluation and follow-up features, has led also to the modification of the original tele-laboratory set-up.

}, keywords = {Robotics}, author = {A. Balestrino and A. Bicchi and A. Caiti and V. Calabr{\`o} and T. Cecchini and A. Coppelli and L. Pallottino and G. Tonietti} } @conference {BGGT05, title = {Hybrid Modelling of an Electronically Controlled Limited Slip Differential}, year = {2005}, month = {8-10 September}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and G. Greco and M. Guiggiani and G. Tonietti} } @article {PPBSV03, title = {Maximizing the stability radius of a set of systems under real-time scheduling constraints}, journal = {IEEE Trans. on Automatic Control}, volume = {50}, number = {11}, year = {2005}, month = {November 2005}, pages = {1790{\textendash}1795}, abstract = {

We address the problem of synthesising real-time embedded controllers taking into account constraints deriving from the implementation platform. Assuming a time-triggered model of computation for tasks controlling a set of independent systems and a real-time preemptive scheduling policy managing a single CPU processor board, we deal with two problems: 1- deciding whether a performance specification can be met on a given platform, 2- optimising performance on a platform. Decision variables of the design problems are the activation periods of the tasks , while the considered performance metric is the minimum stability radius attained over the different feedback loops, which is related to the technological feasibility of the controller and to the robustness of the controlled systems. The analytical formulation of the design problems enables efficient numerical solutions. The resulting control policies are directly implementable without performance degradation that may otherwise arise due to scheduling and execution delays.

}, keywords = {Embedded Control, Robotics}, author = {L. Palopoli and C. Pinello and A. Bicchi and A. L. Sangiovanni-Vincentelli} } @article {BCPT03, title = {On-line Robotic Experiments for Tele-Education at the University of Pisa}, journal = {Int. Journal of Robotic Systems}, volume = {22}, number = {4}, year = {2005}, note = {

Special Issue on Internet \& Online Robots for Telemanipulation

}, pages = {217-230}, abstract = {

In this paper we describe work being done at our department to make the Robotics Laboratory accessible to student and colleagues, to execute and watch real-time experiments at any time and from anywhere. We describe few different installations, and highlight the underlying philosophy, wich is aimed at enlarging the lab in all the dimensions of space, time, and available resources, through the use of Internet technologies.

}, keywords = {Robotics}, author = {A. Bicchi and A. Caiti and L. Pallottino and G. Tonietti} } @article {BSB04, title = {Path-Following with a Bounded-Curvature Vehicle: a Hybrid Control Approach}, journal = {International Journal of Control}, volume = {78}, number = {15}, year = {2005}, month = {October}, pages = {1228-1247}, abstract = {

In this paper, we consider the problem of stabilizing the kinematic model of a car to a path in the plane under rather general conditions. The path is subject to very mild restrictions, while the car model, although rather simplified, contains the most relevant limitations inherent in wheeled robots kinematics. Namely, the car can only move forward, its steering radius is lower bounded and a limited sensory information only provides a partial knowledge of some state parameters. In particular, we consider the case that the current distance and the heading angle error with respect to the closest point on the reference path can be measured but only the sign of the path curvature is detected. These constraints are such to make classical control techniques inefficient. As the feedback information is both continuous and discrete, the hybrid systems formalism turns out to be well appropriate to model the problem. The proposed approach is based on optimal control techniques successfully applied in a previous work for following rectilinear path. We propose here an extension to the tracking of more general paths with moderate curvature. The stability of the closed-loop system is proved by means of the hybrid system formalism and hybrid formal verification techniques. Finally, the practicality of the proposed approach, in spite of non{\textendash}idealities in real-world applications, is discussed by reporting experimental results.

}, keywords = {Embedded Control, Robotics}, author = {A. Balluchi and A. Bicchi and P. Sou{\`e}res} } @conference {IARP05, title = {Physical Human-Robot Interaction in Anthropic Domains: Safety and Dependability}, booktitle = {Proc. 4th IARP/IEEE-EURON Workshop on Technical Challenges for Dependable Robots in Human Environments}, year = {2005}, abstract = {

In this paper we describe the motivations and the aim ofthe EURON-2 research project {\textquoteleft}{\textquoteleft}\underline{P}hysical \underline{H}uman-\underline{R}obot \underline{I}nteraction in Anthropic \underline{Dom}ains{\textquoteright}{\textquoteright} (PRHIDOM). This project, which moves along the lines indicated by the 1$^{st}$ IARP/IEEE-RAS Workshop on Technical Challenge for Dependable Robots in Human Environments \cite{iarp01}, is about {\textquoteleft}{\textquoteleft}charting{\textquoteright}{\textquoteright} the new {\textquoteleft}{\textquoteleft}territory{\textquoteright}{\textquoteright} of physical Human-Robot Interaction (pHRI). To ensure these goals, the integration competences in control, robotics, design and realization of mechanical systems, human-machine interaction, and in safety-dependability of mechatronic systems is required. The PHRIDOM Consortium is composed of 5 partners from 3 different European countries.

}, keywords = {Robotics}, author = {A Albu-Schaeffer and A. Bicchi and G. Boccadamo and R. Chatila and A. De Luca and De Santis, A and G. Giralt and G. Hirzinger and V. Lippiello and R. Mattone and R. Schiavi and B. Siciliano and G. Tonietti and L. Villani} } @conference {ABBPSZ05, title = {Randomized Algorithms for Platform{\textendash}based Design}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2005}, pages = {6638 - 6643}, abstract = {

The design of automotive control systems is becoming increasingly complex as the level of performance required by car manufactures grows continuously and the constraints on cost and development time imposed by the market become tighter. A successful design, without costly and time consuming re-design cycles, can be achieved only by using an efficient design methodology that allows for component re-use and evaluation of platform requirements at the early stages of the design flow. In this paper, we illustrate a control-implementation design methodology for the development of embedded controllers by composition of algorithms picked up from libraries. Randomized algorithms and hybrid system theory are used to develop techniques for functional and architecture evaluations, which are implemented in a prototype tool.

}, keywords = {Embedded Control, Robotics}, author = {A. Agostini and A. Balluchi and A. Bicchi and B. Piccoli and Sangiovanni Vincentelli, A. and K. Zadarnowska} } @conference {FAB05, title = {Visual-based Feedback Control of Casting Manipulation}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2005}, note = {

(ICRA05 B. Wegbreit Award for Best Manipulation Paper)

}, pages = {2203-2208}, abstract = {

In this paper, we present a method to control casting manipulation by means of real-time visual feedback. Casting manipulation is a technique to deploy a robotic end-effector at large distances from the robot{\textquoteright}s base, by throwing the end-effector and controlling its ballistic flight using forces transmitted through a light tether connected to the end-effector itself. The tether cable can also be used to retrieve the end-effector and exert forces on the robot{\textquoteright}s environment. Previous work has shown that casting manipulation is able to catch objects at a large distance, proving it viable for applications such as sample acquisition and return, rescue, etc. In previous experiments, the position of the target object was known exactly. In this paper, we present a first attempt at closing a real-time control loop on casting manipulation using visual feedback of moving targets. As accurate planning methods developed for off-line open-loop planning cannot be used in real-time, we develop a simplified model and control algorithm, whose effectiveness is demonstrated through experiments.

}, keywords = {Robotics}, author = {A. Fagiolini and H. Arisumi and A. Bicchi} } @conference {PPBJ04, title = {Control of Distributed Embedded Systems in the Presence of Unknown{\textendash}but{\textendash}Bounded Noise}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2004}, pages = {1448-1453}, abstract = {

In this paper we consider the problem of controlling multiple scalar systems through a limited capacity shared channel. Each system is affected by process noise and can be controlled byactuators with values in a {\em fixed}inite set. The control objective is to bound the evolution of the systems in specified sets (controlled invariance). Our goal is to find an optimal allocation of the shared communication resource to the different control activities and to identify correct choices for the design parameters. The paper provides fundamental conceptual tools to attack the design problem in the formal framework of an optimization problem. Namely, we give a feasibility criterion to decide whether a set of design parameters conforms with a control specification (i.e., with the controlled invariance of a specified set for each system). Moreover, we offer the explicit computation of the minimum bit rate necessary for the controlled invariance of a set, which is of utmost importance for solving the optimization problem.

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and L. Palopoli and A. Bicchi and K. H. Johansson} } @conference {PSB04, title = {Decentralized Cooperative Conflict Resolution Among Multiple Autonomous Mobile Agents}, booktitle = {cdc}, year = {2004}, pages = {4758-4763}, abstract = {

In this paper we consider policies for cooperative, decentralized traffic management among a number of autonomous mobile agents. The conflict resolution problem is addressed considering realistic restrictions on possible maneuvers. We formulate this problem as one in Mixed Integer Linear Programming (MILP). The method, which proves successful in a centralized implementation with a large number of cooperating agents, is also extended to a decentralized setting. Conditions for the existence of conflict avoidance maneuvers for a system of 5 autonomous agents with a transitive information structure are provided, along with the explicit policy to be applied by each agent.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and V. G. Scordio and A. Bicchi} } @conference {BMP04, title = {Discrete and Hybrid Nonholonomy}, booktitle = {Hybrid Systems: Computation and Control}, series = {LNCS}, volume = {2993}, number = {157{\textendash}172}, year = {2004}, pages = {157-172}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, abstract = {

In this paper we consider the generalization of the classical notion of nonholonomy of smooth constraints in analytical mechanics, to a substantially wider set of systems, allowing for discrete and hybrid (mixed continuous and discrete) configurations and transitions. We show that the general notion of nonholonomy can be captured by the definition of two different types of nonholonomicbehaviours, which we call {\em internal}nd {\em external}, respectively. Examples are reported of systems exhibiting either the former only, or the latter only, or both. For some classes of systems, we provide equivalent or sufficient characterizations of such definitions, which allow for practical tests.

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and A. Marigo and B. Piccoli}, editor = {R. Alur and G. Pappas} } @article {BT03, title = {Fast and Soft Arm Tactics: Dealing with the Safety-Performance Trade-Off in Robot Arms Design and Control}, journal = {IEEE Robotics and Automation Magazine}, volume = {11}, number = {2}, year = {2004}, note = {

PUBLISHER{\textquoteright}S NOTE: In this paper, there are three errors introduced during production. First, the correct title of the article is Fast and Soft Arm Tactics. Also, on formulae for GSI and HIC in page 23, the acceleration is measured in multiples of the acceleration of gravity (g) [not grams], while time is measured in seconds. Finally, within Figure 1, one should read Compliant Covering, and Mrob = Mrotor + Mlink [instead of Krob = Krotor + Klink]. Please visit http://www.ncsu.edu/IEEE-RAS/RAM/BicchiFigure1.pdf to see the original figure.

}, pages = {22{\textendash}33}, abstract = {

In this paper we discuss the problem of achieving good performance in accuracy and promptness by a robot manipulator under the condition that safety is guaranteed throughout task execution. The particular but basic problem of single-joint actuation is considered in detail. Intuitively, while a rigid and powerful structure of the arm would favour its performance, lightweight compliant structures are more suitable to safe operation. The quantitative analysis of the resulting design trade-off between safety and performance is one of the objectives of our work. Such analysis has a strong impact on how robot mechanisms and controllers should be designed for human-interactive applications. We discuss few different possible concepts for safely actuating joints, and focus our attention on one, the Variable-Stiffness Transmission (VST) approach. Some aspects related to the implementation of the mechanics and control of VST joints are reported.

}, keywords = {Robotics}, author = {A. Bicchi and G. Tonietti} } @article {MFB03, title = {A Hybrid-Control Approach to the Parking Problem of a Wheeled Vehicle Using Limited View-Angle Visual Feedback}, journal = {Int. Jour. of Robotics Research}, volume = {23}, number = {4-5}, year = {2004}, month = {April-May}, pages = {437-448}, abstract = {

In this paper we consider the mobile robot parking problem, i.e. the stabilization of a wheeled vehicle to a given position and orientation, using only visual feedback from low-cost cameras. The practically most relevant problem of keeping the tracked features in sight of the camera while maneuvering to park the vehicle is taken into account. This constraint, often neglected in the literature, combines with the nonholonomic nature of the vehicle kinematics in a challenging controller design problem. We provide an effective solution to such problem by using a combination of previous results on non-smooth control synthesis and recently developed hybrid control techniques. Simulations and experimental results on a laboratory vehicle are reported, showing the practicality of the proposed approach.

}, keywords = {Embedded Control, Robotics}, author = {P. Murrieri and D. Fontanelli and A. Bicchi} } @article {1755, title = {Meccanismo motoriduttore a rigidezza variabile e rapidamente controllabile}, year = {2004}, address = {Italy}, keywords = {Robotics}, issn = {PI2004A000077}, author = {A. Bicchi and G. Tonietti} } @conference {PPSB04, title = {Motion Planning through Symbols and Lattices}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2004}, pages = {3914-3919}, abstract = {

In this paper we propose a new approach to motion planning, based on the introduction of a lattice structure in the workspace of the robot, leading to efficient computations of plans for rather complex vehicles, and allowing for the implementation of optimization procedures in a rather straightforward way. The basic idea is the purposeful restriction of the set of possible inputfunctions to the vehicle to a finite set of symbols, or {\em control quanta},which, under suitable conditions, generate a regular lattice of reachable points. Once the lattice is generated and a convenient description computed, standard techniques in integer linear programming can be used to find a plan very efficiently. We also provide a correct and complete algorithm to the problem of finding an optimized plan (with respect e.g. to length minimization) consisting in a sequence of graph searches.

}, keywords = {Embedded Control, Robotics}, author = {S. Pancanti and L. Pallottino and D. Salvadorini and A. Bicchi} } @inbook {BLMS03, title = {On The Problem of Simultaneous Localization, Map Building, and Servoing of Autonomous Vehicles}, booktitle = {Advances in Control of Articulated and Mobile Robots}, series = {STAR - Springer Tracts in Advanced Robotics}, number = {10}, year = {2004}, pages = {223-239}, publisher = {Springer Verlag}, organization = {Springer Verlag}, abstract = {

In this chapter, we consider three of the main problems that arise in the navigation of autonomous vehicles in partially or totally unknown environments, i.e. building a map of the environment, self-localizing, and servoing the robot so as to achieve given goals based on sensorial information. As compared to most part of the existing literature on SLAM, we privilege here a system-theoretic view to the problem, which allows the localization and mapping problems to be cast in a unified framework with the control problem. The chapter is an overview of existing results in this vein, and of some interesting directions for research in the field. All chapters of this volume were revised and published online March 2005. The volume number was corrected from 4010 to 10.

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and F. Lorussi and P. Murrieri and V. G. Scordio}, editor = {B. Siciliano and A. De Luca and C. Melchiorri and G. Casalino} } @conference {BJPP, title = {Quantised Control in Distributed Embedded Systems.}, booktitle = {Proc. 16th Int. Symp. on Mathematical Theory of Networks and Systems}, year = {2004}, abstract = {

Traditional control design is based on ideal assumptions concerning the amount, type and accuracy of the information flow that can be circulated across the controller. Unfortunately, real implementation platforms exhibit non-idealities that may substantially invalidate such assumptions. As a result, the system’s closed-loop performance can be severely affected and sometimes stability itself is jeopardised. These problems show up with particular strength when multiple feedback loops share a limited pool of computation and communication resources. In this case the designer is confronted with the challenging task of choosing at the same time the control law and the optimal allocation policy for the shared resources (control algortihm/system architecture co-design).

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and K. H. Johansson and L. Palopoli and B. Picasso} } @article {MCB04, title = {Reachability and Steering of Rolling Polyhedra: A Case Study in Discrete Nonholonomy}, journal = {IEEE Trans. on Automatic Control}, volume = {49}, number = {5}, year = {2004}, month = {May}, pages = {710-726}, abstract = {

Rolling a ball on a plane is a standard example of nonholonomy reported in many textbooks, and the problem is also well understood for any smooth deformation of the surfaces. For non-smoothly deformed surfaces, however, much less is known. Although it may seem intuitive that nonholonomy is conserved (think e.g. to polyhedral approximations of smooth surfaces), current definitions of {\textquoteleft}{\textquoteleft}nonholonomy{\textquoteright}{\textquoteright} are inherently referred to systems described by ordinary differential equations, and are thus inapplicable to such systems. \{\.I}n this paper we study the set of positions and orientations that a polyhedral part can reach by rolling on a plane through sequences of adjacent faces. We provide a description of such reachable set, discuss conditions under which the set is dense, or discrete, or has a compound structure, and provide a method for steering the system to a desired reachable configuration, robustly with respect to model uncertainties. \\Based on ideas and concepts encountered in this case study, and in some other examples we provide, we turn back to the most general aspects of the problem and investigate the possible generalization of the notion of (kinematic) nonholonomy to non-smooth, discrete, and hybrid dynamical systems. To capture the essence of phenomena commonly regarded as {\textquoteleft}{\textquoteleft}nonholonomic{\textquoteright}{\textquoteright}, at least two irreducible concepts are to be defined, of {\textquoteleft}{\textquoteleft}internal{\textquoteright}{\textquoteright} and {\textquoteleft}{\textquoteleft}external{\textquoteright}{\textquoteright} nonholonomy, which may coexist in the same system. These definitions are instantiated by examples.

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and Y. Chitour and A. Marigo} } @conference {BBCCPPT04, title = {A Robotic Set-Up with Remote Access for {\textquoteleft}{\textquoteleft}Pick and Place{\textquoteright}{\textquoteright} Operations Under Uncertainty Conditions}, booktitle = {E-learning and Virtual and Remote Laboratories}, series = {Proc. VIRTUAL-LAB 2004}, year = {2004}, pages = {144{\textendash}149}, abstract = {

The work describes on-going work at the University of Pisa on the field of tele-laboratories and distance learning. In particular, the group is working at the evolution of existing tele-laboratory experiments in the field of robotics and control into learning units of a self-consistent didactic project. The pick-and-place system described has been designed to provide the set-up for robot arm motion planning with specific objectives and evaluation tools.

}, keywords = {Robotics}, author = {A. Balestrino and A. Bicchi and A. Caiti and T. Cecchini and L. Pallottino and A. Pisani and G. Tonietti}, editor = {P. Borza and L. Gomes and G. Scutaru} } @conference {BTS04, title = {Safe and Fast Actuators for Machines Interacting with Humans}, booktitle = {Proc. of the 1st Technical Exhibition Based Conference on Robotics and Automation, TExCRA2004, November 18-19, TEPIA, Tokyo, Japan -}, year = {2004}, pages = {(in press)}, abstract = {

This paper describes a new generation of actuators for robotic applications, and more generally for machines that are designed to interact with humans. Such actuators, called Variable Impedance Actuators, are designed to achieve fast motion control while guaranteeing safety of human operators in worst-case impact situation. The fundamental innovation is to implement safety by purely mechanical, passive means, to guarantee intrinsic safety, while active control is used to recover performance. The design concept, which is the subject of a patent application, has led to the experimental implementation of a Variable Stiffness Actuator. The effectiveness of the VSA has been recently validated theoretically and experimentally by authors.

}, keywords = {Robotics}, author = {A. Bicchi and G. Tonietti and R. Schiavi} } @conference {PB04mi, title = {Some relations between ergodicity and minimality properties of invariant sets in quantized control systems}, booktitle = {Bifurcations in nonsmooth and hybrid dynamical systems: analysis, control and applications}, series = {S.I.C.C. (Societ\à Italiana Caos e Complessit\à)}, year = {2004}, note = {

poster presentation

}, month = {21-22 October}, address = {Milan}, abstract = {

Linear dynamical systems controlled by quantized inputs exhibit phenomena which are typically non-linear, including chaotic behaviours. We consider discrete-time single-input models of the type x(k+1)=Ax(k)+bu(k). The construction of invariant sets for this class of hybrid systems is of utmost importance for the stabilization problem. We first review a technique to construct invariant sets when an arbitrary quantized input set is assigned. We hence study minimality properties for invariant sets when inputs take integer values. There is a relation between a so-called strong minimality property and ergodicity of the closed-loop dynamics, in particular, ergodicity implies strong minimality. A condition ensuring strong minimality is given in terms of the coefficients of the characteristic polynomial of the matrix {\textquoteright}A{\textquoteright}. Two examples are presented: the first one shows that strong minimality does not imply ergodicity. The second one shows that our condition for strong minimality is only sufficient: this is done by exhibition of an ergodic dynamics for which our condition is not satisfied.

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and A. Bicchi} } @conference {DFMSB03, title = {Cooperative Simultaneous Localization and Map Building for Servoing}, booktitle = {Proceedings of Multiagent Robotic Systems Trends and Industrial Application - Robocup 2003 Conference}, year = {2003}, month = {July}, address = {Padova}, keywords = {Embedded Control, Robotics}, author = {A. Danesi and D. Fontanelli and P. Murrieri and V. G. Scordio and A. Bicchi} } @conference {BMP03, title = {Encoding steering control with symbols}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2003}, pages = {3343-3348}, abstract = {

In this paper, we consider the problem of steering complex dynamical systems among equilibria in their state space in efficient ways. Efficiency is considered as the possibility of compactly representing the (typically very large, or infinite) set of reachable equilibria and quickly computing plans to move among them. To this purpose, we consider the possibility of building lattice structures by purposefully introducing quantization of inputs. We consider different ways in which control actions can be encoded in a finite or numerable set of symbols, review different applications where symbolic encoding of control actions can be employed with success, and provide a unified framework in which to study the many different possible manifestations of the idea.

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and A. Marigo and B. Piccoli} } @conference {OVMB03, title = {From nominal to robust planning: The plate-ball manipulation system}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2003}, month = {May}, pages = {3175-3180}, address = {Taipei, Taiwan}, abstract = {

Robotic manipulation by rolling contacts is an appealing method for achieving dexterity with relatively simple hardware. While there exist techniques for planning motions of rigid bodies in rolling contact under nominal conditions, an inescapable challenge is the design of robust controllers of provable performance in the presence of model perturbations. As a preliminary step in this direction, we present in this paper an iterative robust planner of arbitrary accuracy for the plate-ball manipulation system subject to perturbations on the sphere radius. The basic tool is an exact geometric planner for the nominal system, whose repeated application guarantees the desired robustness property on the basis of the Iterative Steering paradigm. Simulation results under perturbed conditions show the effectiveness of the method.

}, keywords = {Embedded Control, Robotics}, author = {G. Oriolo and M. Vendittelli and A. Marigo and A. Bicchi} } @article {BB02, title = {Necessary and Sufficient Conditions for Robust Perfect Tracking under Variable Structure Control}, journal = {International Journal of Robust and Nonlinear Control}, volume = {13}, number = {2}, year = {2003}, month = {02/2003}, pages = {141-151}, abstract = {

The tracking control of linear MIMO systems with structured uncertainty is considered. A necessary and sufficient condition for robust asymptotic tracking employing variable structure techniques in the presence of multiplicative uncertainty is derived. The constructive proof of the theorem provides an explicit formula for controller synthesis.

}, keywords = {Embedded Control, Robotics}, author = {A. Balluchi and A. Bicchi} } @conference {PCB03, title = {Quality of service control in soft real-time applications}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2003}, pages = {664-669}, abstract = {

In this paper we present results obtained in the context of Quality of Service (QoS) control for soft real-time applications. The discussion addresses the issue of dynamically adjusting the bandwidth for a set of periodic tasks, when a reservation-based (RB) CPU scheduling policy is used. RB techniques are particularly suitable for this kind of applications since they allow an accurate mathematical modelling of the dynamic evolution of the QoS experienced by tasks. Based on this model, a control policy guaranteeing specified QoS levels for different tasks is illustrated, along with necessary and sufficient conditions for its existence. Moreover, the problem of steering a task QoS back into its nominal level is tackled, in response to deviations due to temporary overload conditions. Simulation results are reported, for the purpose of validating the approach.

}, keywords = {Embedded Control, Robotics}, author = {L. Palopoli and T. Cucinotta and A. Bicchi} } @inbook {PB03-ADHS, title = {Receding-Horizon Control of LTI Systems with Quantized Inputs}, booktitle = {Analysis and Design of Hybrid Systems 2003}, year = {2003}, pages = {259-264}, publisher = {Elsevier}, organization = {Elsevier}, abstract = {

This paper deals with the stabilization problem for a particular class of hybrid systems, namely discrete-time linear systems subject to a uniform (a priori fixed) quantization of the control set. Results of our previous work on the subject provided a description of minimal (in a specific sense) invariant sets that could be rendered maximally attractive under any quantized feedback strategy. In this paper, we consider the design of stabilizing laws that optimize a given cost index on the state and input evolution on a finite, receding horizon. Application of Model Predictive Control techniques for the solution of similar hybrid control problems through Mixed Logical Dynamical reformulations can provide a stabilizing control law, provided that the feasibility hypotheses are met. In this paper, we discuss precisely what are the shortest horizon length and the minimal invariant terminal set for which it can be guaranteed a stabilizing MPC scheme. The final paper will provide an example and simulations of the application of the control scheme to a practical quantized control problem.

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and S. Pancanti and A. Bemporad and A. Bicchi}, editor = {Gueguen Engell and Zaytoon} } @conference {ZBSVB03, title = {Stabilization of a class of discrete-time hybrid automata}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2003}, pages = {1147-1152}, abstract = {

In this paper, the problem of stabilizing linear discrete time hybrid automata is considered. A synthesis methodology is obtained by extending to hybrid systems the stabilization techniques based on stable convex combinations, originally developed for switching systems. An algorithm to explore the candidate stabilizing controller actions is proposed and an application to an automotive engine control problem is described.

}, keywords = {Embedded Control, Robotics}, author = {M. Zoncu and A. Balluchi and A. Sangiovanni Vincentelli and A. Bicchi} } @inbook {PB03-HSCC, title = {Stabilization of LTI Systems with Quantized State-Quantized Input Static Feedback}, booktitle = {Hybrid Systems: Computation and Control}, series = {Lecture Notes in Computer Science}, volume = {LNCS 2623}, year = {2003}, pages = {405-416}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Heidelberg, Germany}, abstract = {

This paper is concerned with the stabilization problem for discrete-time linear systems subject to a uniform quantization of the control set and to a regular state quantization, both fixed a priori. As it is well known, for quantized systems only weak (practical) stability properties can be achieved. Therefore, we focus on the existence and construction of quantized controllers (mapping a quantized state into a quantized input set) capable of steering a system to within invariant neighbourhoods of the equilibrium. Such analysis is helpful because it allows to decide a priori whether adesired control objective can be achieved by using a \textit{given} technology (actuators, sensors, communication and computational means).

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and A. Bicchi}, editor = {A. Pnueli and O. Maler} } @inbook {BTBP03, title = {Variable Stiffness Actuators for Fast and Safe Motion Control}, booktitle = {Proceedings of the International Symposium on Robotics Research}, series = {Springer Tracts in Advanced Robotics (STAR)}, year = {2003}, publisher = {Springer Verlag}, organization = {Springer Verlag}, abstract = {

In this paper we propose Variable Stiffness actuation as a viable mechanical/control co-design approach for guaranteeing control performance for robot arms that are inherently safe to humans in their environment. A new actuator under development in our Lab is then proposed, which incorporate the possibility to vary transmission stiffness during motion execution, thus allowing substantial motion speed-up while maintaining low injury risk levels.

}, keywords = {Robotics}, author = {A. Bicchi and G. Tonietti and M. Bavaro and M. Piccigallo}, editor = {B. Siciliano and O. Khatib and Groen, F.} } @conference {TB02, title = {Adaptive Simultaneous Position and Stiffness Control for a Soft Robot Arm}, booktitle = {Proc. IEEE Int. Symp. Intelligent Robots and Systems}, year = {2002}, month = {October}, pages = {1992-1997}, abstract = {

In this paper, an independent joint position and stiffness adaptive control for a robot arm actuated by McKibbenartificial muscles is reported. In particular, {\em muscular} nd {\em dynamic} parameters of the system are supposed unknown. Adaptive control performance is tested in a one degree of freedom experimental setup and compared with PID control performance. The adaptive control scheme is then applied to a robot arm that is conceived to perform tasks in an anthropic environment. The adaptive control developed is such that performance of the robot arm is very similar to this of human arm. Experimental results are reported.

}, keywords = {Robotics}, author = {G. Tonietti and A. Bicchi} } @article {PFB02-TITS, title = {Conflict Resolution Problems for Air Traffic Management Systems Solved with Mixed Integer Programming}, journal = {IEEE Trans. Intelligent Transportation Systems}, volume = {3}, number = {1}, year = {2002}, month = {March}, pages = {3-11}, abstract = {

This paper considers the problem of solving conflicts arising among several aircraft that are assumed to move in a shared airspace. Aircraft can not get closer to each other than a given safety distance in order to avoid possible conflicts between different airplanes. For such system of multiple aircraft, we consider the path planning problem among given waypoints avoiding all possible conflicts. In particular we are interested in optimal paths, i.e. we want to minimize the total flight time. We propose two different formulations of the multi-aircraft conflict avoidance problem as a mixed-integer linear program: in the first case only velocity changes are admissible maneuvers, in the second one only heading angle changes are allowed. Due to the linear formulation of the two problems, solutions may be obtained quickly with standard optimization software, allowing our approach to be implemented in real time.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and E. Feron and A. Bicchi} } @conference {PGB02, title = {Construction of invariant and attractive sets for quantized-input linear systems}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2002}, month = {December}, pages = {824-829}, abstract = {

In this paper, the problem of the stabilization of a discrete-time linear system subject to a fixed and uniformly quantized control set is considered. It is well known that, working with quantized inputs, the states of the system (except for a negligible set of initial conditions) cannot reach asymptotically the equilibrium point. Our aim is then to find an invariant and attractive neighborhood of the equilibrium and provide with a controller which steers the system into it. We construct a continuous and increasing family of invariant sets including one which is, in a specific sense, minimal. The invariance and attractivity properties of such sets are revised in the finite control set case: we propose a family of controllers taking on a finite number of values and ensuring the system convergence to the minimal invariant set. Some consequences of our technique are underlined with particular regard to the usage of Model Predictive Control tools. In the last section an example which shows the effectiveness of our results is presented.

}, keywords = {Embedded Control, Robotics}, author = {B. Picasso and F. Gouaisbaut and A. Bicchi} } @book {BCP02, title = {Control Problems in Robotics}, volume = {4}, year = {2002}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin Heidelberg}, keywords = {Robotics}, editor = {A. Bicchi and H. Christensen and D Prattichizzo} } @conference {MFBENEA02, title = {Controllo Ibrido di Veicoli su Ruote con Retroazione Visiva}, booktitle = {Proc. 1st. Natl. Conf. and Exhibit on Autonomous Intelligent Systems and Advanced Robotics}, year = {2002}, month = {October}, pages = {197-199}, address = {ENEA, Frascati}, keywords = {Embedded Control, Robotics}, author = {P. Murrieri and D. Fontanelli and A. Bicchi} } @conference {TB02-IARP, title = {Design, Realization and Control of Soft Robot Arms for Intrinsically Safe Interaction with Humans}, booktitle = {Proc. IARP/RAS Workshop on Technical Challenges for Dependable Robots in Human Environments}, year = {2002}, month = {October}, pages = {79-87}, keywords = {Robotics}, author = {A. Bicchi and G. Tonietti} } @article {BM02, title = {Dexterous Grippers: Putting Nonholonomy to Work for Fine Manipulation}, journal = {Int. Jour. of Robotics Research}, volume = {21}, number = {5-6}, year = {2002}, note = {

Special Issue on Nonholonomy on Purpose, H. Arai, A. Bicchi, eds.

}, month = {May-June}, pages = {427-442}, keywords = {Robotics}, author = {A. Bicchi and A. Marigo} } @article {BA02, title = {Editorial for the Special Issue on Nonholonomy on Purpose}, journal = {Int. Jour. of Robotics Research}, volume = {21}, number = {5-6}, year = {2002}, month = {May-June}, pages = {387-388}, keywords = {Robotics}, author = {A. Bicchi and H. Arai} } @conference {PB02, title = {Grasp Control: a General Manipulation System Approach}, booktitle = {Proc. Int. Works. Towards Intelligent Robotic Manipulation}, year = {2002}, month = {September}, publisher = {IEEE/RSJ IROS}, organization = {IEEE/RSJ IROS}, address = {Lausanne}, keywords = {Haptics, Robotics}, author = {D Prattichizzo and A. Bicchi}, editor = {C. Melchiorri and P. J. Sanz and R. Molfino} } @conference {MPB02, title = {A Group-Theoretic Characterization of Quantized Control Systems}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2002}, month = {December}, pages = {811-816}, abstract = {

In this paper we consider the reachability problem for quantized control systems, i.e. systems that take inputs from a finite set of symbols. Previous work addressed this problem for linear systems and for some specific classes of nonlinear driftless systems. In this paper we attack the study of more general nonlinear systems. To do so we find it useful to pose the problem in more abstract terms, and make use of the wealth of tools available in group theory, which enables us to proceed in our agenda of better understanding effects of quantization of inputs on dynamic systems.

}, keywords = {Embedded Control, Robotics}, author = {A. Marigo and B. Piccoli and A. Bicchi} } @conference {MB02-ICRA, title = {A local-local planning algorithm for rolling objects}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2002}, month = {May}, pages = {1759-1764}, abstract = {

In this paper, we consider planning motions of objects of regular shape rolling on a plane among obstacles. Theoretical foundations and applications of this type of operations in robotic manipulation and locomotion have been discussed elsewhere. In this paper, we propose a novel algorithm that improves upon existing techniques in that: i) it is finitely computable and predictable (an upper bound on the computations necessary to reach a given goal within a tolerance can be given), and ii) it possesses a topological (local-local) property which enables obstacles and workspace limitations to be dealt with in an effective way.

}, keywords = {Embedded Control, Robotics}, author = {A. Marigo and A. Bicchi} } @conference {PBSV02, title = {Numerically efficient control of systems with communication constraints}, booktitle = {Proc. IEEE Int. Conf. on Decision and Control}, year = {2002}, month = {December}, pages = {1626-1631}, abstract = {

The problem of stabilization to the trivial equilibrium of a system with communication constraints is addressed. The communication constraints are related to the fact that commands are issued to different groups of actuators through a shared resource. We tackle the problem by using a Model Predictive Control scheme, which,at every step, decides the allocation of the bus {\em and} he control command values. After discussing two different alternatives for dealing with the scheduling constraints, we develop a formulation based on the generalized linear complementarity problem, which enables the application of efficient numerical solutions. Finally, we give some preliminary result on the parametric dependence of the problem{\textquoteright}s solution from the system{\textquoteright}s state.

}, keywords = {Embedded Control, Robotics}, author = {L. Palopoli and A. Bicchi and A. L. Sangiovanni-Vincentelli} } @inbook {PLPB02, title = {Optimal control of quantized input systems}, booktitle = {Hybrid Systems: Computation and Control}, series = {Lecture Notes in Computer Science}, volume = {LNCS 2289}, year = {2002}, pages = {351-363}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Heidelberg, Germany}, abstract = {

In this paper we consider the problem of optimal control (specifically, minimum-time steering) for systems with quantized inputs. In particular, we propose a new approach to the solution of the optimal control problem for an important class of nonlinear systems, i.e. chained-form systems. By exploiting results on the structure of the reachability set of these systems under quantized control, the optimal solution is determined solving an integer linear programming problem. Our algorithm represents an improvement with respect to classical approaches in terms of exactness, as it does not resort to any a priori state-space discretization. Although the computational complexity of the problem in our formulation is still formally exponential, it lends itself to application of Branch and Bound techniques, which substantially cuts down computations in many cases, as it has been experimentally observed.

}, keywords = {Embedded Control, Robotics}, author = {S. Pancanti and L. Leonardi and L. Pallottino and A. Bicchi}, editor = {C. Tomlin and M. Greenstreet} } @conference {PPB02, title = {On Optimal Steering of Quantized Input Systems}, booktitle = {Proceedings of the NSF/ONR Workshop on Future Directions in Nonlinear Control of Mechanical Systems}, year = {2002}, address = {Urbana, IL.}, abstract = {

In this paper we consider the problem of optimal control (specifically, minimum-time steering) for systems with quantized inputs. In particular, we propose a new approach to the solution of the optimal control problem for an important class of nonlinear systems, i.e. chained-form systems. By exploiting results on the structure of the reachability set of these systems under quantized control, the optimal solution is determined solving an integer linear programming problem. Our algorithm represents an improvement with respect to classical approaches in terms of exactness, as it does not resort to any a priori state-space discretization. Although the computational complexity of the problem in our formulation is still formally exponential, it lends itself to application of Branch and Bound techniques, which substantially cuts down computations in many cases, as it has been experimentally observed.

}, keywords = {Embedded Control, Robotics}, author = {S. Pancanti and L. Pallottino and A. Bicchi} } @article {BMP02, title = {On the reachability of quantized control systems}, journal = {IEEE Trans. on Automatic Control}, volume = {4}, number = {47}, year = {2002}, month = {April}, pages = {546-563}, abstract = {

In this paper we study control systems whose input sets are quantized, i.e. finite or regularly distributed on a mesh. We specifically focus on problems relating to the structure of the reachable set of such systems, which may turn out to be either dense or discrete. We report results on the reachable set of linear quantized systems, and on a particular but interesting class of nonlinear systems, i.e. nonholonomic chained-form systems. For such systems, we provide a complete characterization of the reachable set, and, in the case the set is discrete, a computable method to completely and succinctly describe its structure. Implications and open problems in the analysis and synthesis of quantized control systems are addressed.

}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi and A. Marigo and B. Piccoli} } @conference {PBENEA02, title = {Risoluzione ottima dei conflitti tra agenti autonomi: applicazione al controllo del traffico aereo}, booktitle = {Proc. 1st. Natl. Conf. and Exhibit on Autonomous Intelligent Systems and Advanced Robotics}, year = {2002}, month = {October}, pages = {193-197}, address = {ENEA, Frascati}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and A. Bicchi} } @conference {PBP02, title = {Safety of a decentralized scheme for Free-Flight ATMS using Mixed Integer Linear Programming}, booktitle = {American Control Conference}, year = {2002}, month = {May}, pages = {742-747}, abstract = {

In this paper we consider policies for free-flight management of air traffic. We consider instantaneous and bounded heading angle deviation as conflict avoidance maneuvers. The corresponding model, resulting in a Mixed Integer Linear Programming (MILP) problem allow to solve both conflict detection and conflict resolution problems. The developed algorithm proved successful in a centralized implementation with a large number of cooperating aircraft. However, the application of such algorithm to a Free Flight environment, where cooperation can only be expected from neighboring aircraft, poses many challenges. We consider a model of the decentralized conflict resolution strategy that is based on a hybrid system, and sufficient conditions under which a 3-aircraft Free Flight MILP-based scheme guarantees safety of flight are provided.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and A. Bicchi and S. Pancanti} } @inbook {PPSEB02, title = {Synthesis of robust control systems under resource constraints}, booktitle = {Hybrid Systems: Computation and Control}, series = {Lecture Notes in Computer Science}, volume = {LNCS 2289}, year = {2002}, pages = {337-350}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Heidelberg, Germany}, keywords = {Embedded Control, Robotics}, author = {L. Palopoli and C. Pinello and A. L. Sangiovanni-Vincentelli and L. El-Ghaoui and A. Bicchi}, editor = {M. Greenstreet and C. Tomlin} } @inbook {MFB02, title = {Visual-servoed parking with limited view angle}, booktitle = {Experimental Robotics VIII}, series = {Springer Tracts in Advanced Robotics (STAR)}, volume = {5}, year = {2002}, pages = {254-263}, publisher = {Springer Verlag}, organization = {Springer Verlag}, abstract = {

In this paper the problem of stabilizing a wheeled vehicle of unicycle type to a set point, using only visual feedback, is considered. The practically most relevant problem of keeping the tracked features in sight of the camera while maneuvering to park the vehicle is taken into account. This constraint, often neglected in the literature, combines with the nonholonomic nature of the vehicle kinematics in a challenging controller design problem. We provide an effective solution to such problem by using a combination of previous results on non-smooth control synthesis, and recently developed hybrid control techniques. Simulations and experimental results on a laboratory vehicle are reported, showing the practicality of the proposed approach.

}, keywords = {Embedded Control, Robotics}, author = {P. Murrieri and D. Fontanelli and A. Bicchi}, editor = {B. Siciliano and P. Dario} } @conference {SB-01, title = {Tactile Flow: Does it exist, is it useful and how?}, booktitle = {Proc. Int. Worksh. on Electroactive Polymers and Biosystems}, year = {2001}, month = {July}, pages = {142}, address = {Lucca, Italy}, keywords = {Bioengineering, Haptics, Robotics}, author = {E. P. Scilingo and A. Bicchi} } @inbook {BSDR00, title = {Experimental Validation of a Psychophysical Conjecture on a Simplified Model of the Haptic Perceptual Channel}, booktitle = {Robotics Research IX}, year = {2000}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, keywords = {Haptics, Robotics}, author = {A. Bicchi and E. P. Scilingo and D. De Rossi} } @conference {SBB00, title = {Optimal Feedback Control for Route Tracking with a Bounded-Curvature Vehicle}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {2000}, month = {April}, pages = {2473-2478}, address = {San Francisco, CA, USA}, keywords = {Robotics}, author = {P. Sou{\`e}res and A. Balluchi and A. Bicchi} } @conference {PPB00, title = {Shortest paths for teams of vehicles}, booktitle = {Proc. WAC Int. Symp. on Robotics and Applications}, year = {2000}, month = {June}, pages = {124-129}, abstract = {

In this paper we consider the problem of planning motions of a team of vehicles that move in a planar environment. Each vehicle is modelled as a kinematic system with velocity constraints and curvature bounds. Vehicles can not get closer to each other than a predefined safety distance. When manipulating a common object cooperatively, further constraints apply. For such systems, we consider the problem of planning optimal paths in the absence of obstacles.

}, keywords = {Embedded Control, Robotics}, author = {L. Pallottino and G. Parlangeli and A. Bicchi} } @inbook {B99, title = {An experimental study of performance and fault tolerance of a hybrid free-flight control scheme}, booktitle = {Robustness in Identification and Control}, series = {LNCIS 245}, year = {1999}, pages = {449-463}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin Heidelberg, Germany}, keywords = {Embedded Control, Robotics}, author = {A. Bicchi}, editor = {A. Garulli and A. Tesi and A. Vicino} } @conference {BDRS99, title = {Psychophysical Evaluation of Simplified Haptic Perception Media}, booktitle = {Proc. Int. Workshop on Robot and Human Interaction}, year = {1999}, month = {September}, address = {Pisa}, abstract = {

Detection of softness by tactile exploration in humans is based on both kinesthetic and cutaneous perception, and haptic displays should be designed so as to address such multimodal perceptual channel. Unfortunately, accurate detection and replication of cutaneous information in all its details is difficlt and costly. In this paper we discuss a simplified model of haptic detection of softness (whereby only information on the rate of spread of the contact area between the finger and the specimen as the contact force increases is transmitted). We provide a thorough set of psychophysical tests, to support the feasibility (in at least some contexts) of a reduced-complicacy display of haptic features.

}, keywords = {Bioengineering, Haptics, Robotics}, author = {A. Bicchi and D. De Rossi and E. P. Scilingo} } @conference {ABDRS99, title = {The Role of Contact Area Spread Rate in Haptic Discrimination of Softness}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {1999}, pages = {305-310}, abstract = {

Many applications in teleoperation and virtual reality call for the implementation of effective means of displaying to the human operator information on the softness and other mechanical properties of objects being touched. The ability of humans to detect softness of different objects by tactual exploration is intimately related to both kinesthetic and cutaneous perception, and haptic displays should be designed so as to address such multimodal perceptual channel. Unfortunately, accurate detection and replication of cutaneous information in all its details appears to be a formidable task for current technology, causing most of today{\textquoteright}s haptic displays to merely address the kinesthetic part of haptic information. In this paper we investigate the possibility of surrogating detailed tactile information for softness discrimination, with information on the rate of spread of the contact area between the finger and the specimen. Devices for implementing this new perceptual channel are described, and some preliminary psychophysical test results are reported, validating the effectiveness and practicality of the proposed approach.

}, keywords = {Bioengineering, Haptics, Robotics}, author = {G. Ambrosi and A. Bicchi and D. De Rossi and E. P. Scilingo} } @conference {PMBV98, title = {Active Suspensions Decoupling by Algebraic Output Feedback}, booktitle = {Proc. IEEE Mediterranean Conf. On Control And Systems}, year = {1998}, keywords = {Embedded Control, Robotics}, author = {D Prattichizzo and P. Mercorelli and A. Bicchi and A. Vicino} } @conference {SBDRI-98, title = {Haptic display able to replicate the rheological behaviour of surgical tissues}, booktitle = {Proc. 20th International Conference IEEE/EMBS}, year = {1998}, pages = {1738-1741}, address = {Hong Kong}, keywords = {Bioengineering, Haptics, Robotics}, author = {E. P. Scilingo and A. Bicchi and D. De Rossi and P. Iacconi} } @conference {BPA98, title = {Optimization of Internal Forces in Force-Closure Grasps}, booktitle = {Proc. IEEE Mediterranean Conf. On Control And Systems}, year = {1998}, keywords = {Haptics, Robotics}, author = {A. Bicchi and D Prattichizzo and G. Antognetti} } @conference {PMBV97-CIS, title = {Geometric Control Techniques for Manipulation Systems}, booktitle = {Proceeding Int. Conf. Computer Integrated Systems}, year = {1997}, address = {Belfort, France}, keywords = {Haptics, Robotics}, author = {D Prattichizzo and P. Mercorelli and A. Bicchi and A. Vicino} } @conference {PMBV97-AIMETA, title = {Geometric Control Techniques for Mechanical Systems}, booktitle = {Int. Conf. Italian Association for Theretical and Applied Mechanics}, year = {1997}, address = {Siena, Italia, september 29 - October 3 1997}, keywords = {Haptics, Robotics}, author = {D Prattichizzo and P. Mercorelli and A. Bicchi and A. Vicino} } @conference {SDRBI97-ASME, title = {Haptic display for replication of rheological behaviour of surgical tissues: modelling, control, and experiments}, booktitle = {Proc. Annual ASME Symp. on Haptic Interfaces for Virtual Environments and Teleoperator Systems}, year = {1997}, address = {Dallas}, keywords = {Bioengineering, Haptics, Robotics}, author = {E. P. Scilingo and D. De Rossi and A. Bicchi and P. Iaccone} } @conference {BCP97, title = {Optimal Design of Dynamic Force/Torque Sensors}, booktitle = {Proceeding Int. Conf. Computer Integrated Systems}, year = {1997}, address = {Belfort, France}, keywords = {Robotics}, author = {A. Bicchi and A. Caiti and D Prattichizzo} } @inbook {BMP99-CPRA, title = {Robotic Dexterity via Nonholonomy}, booktitle = {Control Problems in Robotics and Automation}, series = {LNCIS 230}, year = {1997}, pages = {35-49}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin Heidelberg, Germany}, keywords = {Haptics, Robotics}, author = {A. Bicchi and A. Marigo and D Prattichizzo}, editor = {B. Siciliano and K. Valavanis} } @inbook {CMPB97, title = {Rolling Polyhedra on a Plane: Analysis of the Reachable Set}, booktitle = {Algorithms for Robotic Motion and Manipulation}, year = {1997}, pages = {277-286}, publisher = {A. K. Peters}, organization = {A. K. Peters}, address = {Wellesley, MA, U.S.A.}, keywords = {Embedded Control, Robotics}, author = {Y. Chitour and A. Marigo and D Prattichizzo and A. Bicchi}, editor = {J.P. Laumond and M. Overmars} } @inbook {BP97, title = {On some structural properties of general manipulation systems}, booktitle = {Modelling and Control of Mechanichal Systems}, year = {1997}, pages = {187-202}, publisher = {Imperial College Press}, organization = {Imperial College Press}, address = {London, U.K.}, keywords = {Haptics, Robotics}, author = {A. Bicchi and D Prattichizzo}, editor = {A. Astolfi and D. J. N. Limebeer and C. Melchiorri and A. Tornamb\èe and R.B. Vinter} } @inbook {CMPB96, title = {Reachability of Rolling Parts}, booktitle = {Advances in Robotics: The ERNET Perspective}, year = {1996}, pages = {51-60}, publisher = {World Scientific Publisher Corp.}, organization = {World Scientific Publisher Corp.}, address = {Singapore}, keywords = {Haptics, Robotics}, author = {Y. Chitour and A. Marigo and D Prattichizzo and A. Bicchi}, editor = {C. Bonivento and C. Melchiorri and H. Tolle} } @article {1751, title = {Calibration technique for Intrinsic Tactile Sensors}, year = {1995}, note = {

Italian Patent

}, address = {Italy}, keywords = {Robotics}, issn = {FI95A000108}, author = {A. Bicchi and F. Granata} } @article {B95, title = {On the Closure Properties of Robotic Grasping}, journal = {The Int. J. of Robotics Research}, volume = {14}, number = {4}, year = {1995}, month = {August}, pages = {319-334}, keywords = {Haptics, Robotics}, author = {A. Bicchi} } @conference {BP94, title = {Controllability of whole-arm manipulation}, booktitle = {Proc. Int. Conf. Decision and Control}, year = {1994}, pages = {373-374}, keywords = {Haptics, Robotics}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=410900}, author = {A. Bicchi and D Prattichizzo} } @article {B94, title = {On the Problem of Decomposing Grasp and Manipulation Forces in Multiple Whole-Limb Manipulation}, journal = {Int. Journal of Robotics and Autonomous Systems}, volume = {13}, year = {1994}, pages = {127-147}, keywords = {Grasping, Robotics}, author = {A. Bicchi} } @inbook {BSB93, title = {Experimental Evaluation of Friction Data with an Articulated Hand and Intrinsic Contact Sensors}, booktitle = {Experimental Robotics-III}, series = {LNCIS 190}, year = {1993}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin Heidelberg, Germany}, keywords = {Haptics, Robotics}, author = {A. Bicchi and J. K. Salisbury and D. L. Brock}, editor = {R. Chatila and G. Hirzinger} } @conference {BM93, title = {Manipulability Measures of Cooperating Arms}, booktitle = {Proc. American Control Conference}, year = {1993}, keywords = {Haptics, Robotics}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=4792867}, author = {A. Bicchi and C. Melchiorri} } @inbook {BP93, title = {New Issues in the Kineto-Statics, Dynamics, and Control of Whole-Hand Manipulation}, booktitle = {Robotics, Mechatronics and Manufacturing Systems}, year = {1993}, pages = {373-3790}, publisher = {North Holland}, organization = {North Holland}, address = {Amsterdam}, keywords = {Haptics, Robotics}, author = {A. Bicchi and D Prattichizzo}, editor = {T. Takamori and K. Tsuchiya} } @conference {PBC93, title = {Statically Stable Legged Locomotion with Leg Redundancy}, booktitle = {Proc. IASTED Int. Conf. on Robotics and Manufacturing}, year = {1993}, publisher = {IASTED}, organization = {IASTED}, address = {Oxford, UK, september 23-25 1993}, keywords = {Embedded Control, Robotics}, issn = {O-88986-179-X}, author = {D Prattichizzo and A. Bicchi and G. Casalino} } @conference {BBLP93, title = {A variable structure approach to force/motion control of robot manipulators}, booktitle = {Proc. Int. Conf. FAST - BIAS}, year = {1993}, address = {Milan, Italy, November 23-25 1993}, keywords = {Robotics}, author = {A. Balestrino and A. Bicchi and A. Landi and D Prattichizzo} } @inbook {VB93, title = {Whole Hand Manipulation: Design of an Articulated Hand Exploiting All Its Parts To Increase Dexterity}, booktitle = {Robots and Biological Systems}, series = {NATO-ASI Series F: Computer and Systems Sciences, vol. 102}, year = {1993}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin Heidelberg, Germany}, keywords = {Haptics, Robotics}, author = {G. Vassura and A. Bicchi}, editor = {P. Dario and P. Aebischer and G. Sandini} } @conference {1879, title = {Adaptive neural state observer for unknown non linear plants}, booktitle = {IMACS/SICE International Symposium on Robotics, Mechatronics and Manufacturing Systems}, year = {1992}, address = {Kobe, Japan, Sep 16-20 1992}, keywords = {Robotics}, author = {Bini Verona, F and A. Bicchi and De Gasperis, G. and A. Landi and G. Silvestri} } @inbook {DBBF92, title = {Multiple Sensing for Dexterous End Effectors}, booktitle = {Robots with redundancy: design, sensing and control}, year = {1992}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin Heidelberg, Germany}, keywords = {Haptics, Robotics}, author = {P. Dario and M. Bergamasco and A. Bicchi and A. Fiorillo}, editor = {A. K. Bejczy} } @inbook {BM92, title = {Quasi-Static Compensation of Force Errors for Flexible Manipulators}, booktitle = {Selected papers from the Third IFAC/IFIS/IMAC Symposium on Robot Control}, year = {1992}, pages = {381-385}, publisher = {Pergamon Press Books}, organization = {Pergamon Press Books}, address = {Oxford, U.K.}, keywords = {Robotics}, author = {A. Bicchi and C. Melchiorri}, editor = {I. Troch and K. Desoer and P. Kopacek} } @inbook {BBD92, title = {Robot Tactile Perception}, booktitle = {Sensor Based Robots: Algorithms and Architectures}, year = {1992}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin Heidelberg, Germany}, keywords = {Haptics, Robotics}, author = {G. Buttazzo and A. Bicchi and P. Dario}, editor = {C. S. G. Lee} } @conference {BBL92, title = {Trajectory Planning of Industrial Robots in a Structured Environment}, booktitle = {Int. Conf. on CAD/CAM, Robotics and Factories of the Future}, year = {1992}, address = {Metz, France}, keywords = {Embedded Control, Robotics}, author = {A. Balestrino and A. Bicchi and A. Landi} } @inbook {BB91, title = {Robotic Tactile Sensing: Skin-like and Intrinsic Approach}, booktitle = {Intelligent Robotic Systems: Analysis, Design and Programming}, year = {1991}, publisher = {Marcel Dekker}, organization = {Marcel Dekker}, address = {New York, NY, USA}, keywords = {Haptics, Robotics}, author = {A. Bicchi and G. Buttazzo}, editor = {S. Tzafestas} } @inbook {BDBB90, title = {Multi Sensor Integration for Fine Manipulation}, booktitle = {Highly Redundant Sensing in Robotic Systems}, series = {NATO-ASI Series F: Computer and Systems Sciences, vol. 58}, volume = {58}, number = {NATO ASI Series}, year = {1990}, pages = {55-66}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin Heidelberg, Germany}, keywords = {Haptics, Robotics}, author = {M. Bergamasco and P. Dario and A. Bicchi and G. Buttazzo}, editor = {J. T. Tou and J. G. Balchen} } @conference {BB89, title = {Adaptive Surface Following and Reconstruction Using Intrinsic Tactile Sensing}, booktitle = {Proc. IEEE Int. Works. on Sensorial Integration for Industrial Robots}, year = {1989}, address = {Zaragoza, Spain}, keywords = {Haptics, Robotics}, author = {A. Balestrino and A. Bicchi} } @conference {BBDGMP89, title = {Leg-Ankle-Foot System for Investigating Sensor Based Legged Locomotion}, booktitle = {Proc. IEEE/RSJ Int. Conf. on Intelligent Robots and Systems}, year = {1989}, address = {Tsukuba, Japan}, keywords = {Embedded Control, Robotics}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=637970}, author = {A. Bicchi and L. Bosio and P. Dario and M. Guiggiani and E. Manfredi and P. C. Pinotti} } @inbook {BD88, title = {Intrinsic Tactile Sensing for Artificial Hands}, booktitle = {Robotics Research - IV}, year = {1988}, pages = {83-90}, publisher = {MIT Press}, organization = {MIT Press}, address = {Cambridge, MA, USA}, keywords = {Haptics, Robotics}, author = {A. Bicchi and P. Dario}, editor = {R. Bolles and B. Roth} } @inbook {DBFBF86, title = {A Sensorized Scenario for Basic Investigation on Active Touch}, booktitle = {Robot Sensors: Tactile and Non-Vision}, series = {International Trends in Manufacturing Technology Series, vol. 2}, year = {1986}, pages = {237-245}, publisher = {I. F. S. Publications Ltd.}, organization = {I. F. S. Publications Ltd.}, address = {Kempston, Bedford, U. K.}, keywords = {Haptics, Robotics}, author = {P. Dario and A. Bicchi and A. Fiorillo and G. Buttazzo and R. Francesconi}, editor = {Alan Pugh} } @conference {1880, title = {On the Control of a Sensorized Artificial Finger for Tactile Exploration of Objects}, booktitle = {IFAC Symposium on Robot Control (SYROCO85)}, year = {1985}, address = {Barcelona, Spain, 6-8 November 1985}, keywords = {Haptics, Robotics}, author = {A. Bicchi and P. Dario and P. C. Pinotti} } @conference {DBVP85, title = {Tendon Actuated Exploratory Finger With Polymeric, Skin-like Tactile Sensor}, booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation}, year = {1985}, address = {St. Louis, MO, USA.}, keywords = {Haptics, Robot Hands, Robotics, Sensors}, author = {P. Dario and A. Bicchi and F. Vivaldi and P. C. Pinotti} }