@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} } @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} } @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} } @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} } @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} } @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} } @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} } @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} } @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 {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 {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} } @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} } @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} } @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} } @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} } @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} } @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 {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 {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 {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} } @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 {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} } @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 {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} } @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} } @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 {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 {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} } @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 {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 {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 {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} } @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 {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} } @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 {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 {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 {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} }