@conference {3150, title = {A real-time identification and tracking method for the musculoskeletal model of human arm}, booktitle = {2018 IEEE International Conference on Systems, Man, and Cybernetics (SMC) }, year = {2019}, author = {C. Fang and A. Ajoudani and A. Bicchi and N. G. Tsagarakis} } @inbook {3381, title = {WALK-MAN Humanoid Platform}, booktitle = {The DARPA Robotics Challenge Finals: Humanoid Robots To The Rescue}, volume = {121}, number = {The DARPA Robotics Challenge Finals: Humanoid Robots To The Rescue}, year = {2018}, pages = {495{\textendash}548}, publisher = {Springer}, organization = {Springer}, doi = {10.1007/978-3-319-74666-1_13}, author = {N. G. Tsagarakis and F. Negrello and M. Garabini and W. Choi and L. Baccelliere and V. G. Loc and J. Noorden and M. G. Catalano and M. Ferrati and L. Muratore and P. Kryczka and E. Mingo Hoffman and A Settimi and A. Rocchi and A. Margan and S. Cordasco and D. Kanoulas and A. Cardellino and L. Natale and H. Dallali and J. Malzahn and N. Kashiri and V. Varricchio and L. Pallottino and C. Pavan and J. Lee and A. Ajoudani and D. G. Caldwell 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} } @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} } @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 {3152, title = {Reduced-Complexity Representation of the Human Arm Active Endpoint Stiffness for Supervisory Control of Remote Manipulation}, journal = {International Journal of Robotics Research}, volume = {37}, year = {2017}, month = {11/2017}, chapter = {155}, doi = {https://doi.org/10.1177\%2F0278364917744035}, url = {https://journals.sagepub.com/doi/full/10.1177/0278364917744035}, author = {A. Ajoudani and C. Fang and N. G. Tsagarakis 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} } @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} } @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} } @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 {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} } @article {2749, title = {The Walk-Man Robot Software Architecture}, journal = {Front. Robot. AI}, year = {2016}, month = {05/2016}, abstract = {

A software and control architecture for a humanoid robot is a complex and large project, which involves a team of developers/researchers to be coordinated and requires many hard design choices. If such project has to be done in a very limited time, i.e., less than 1 year, more constraints are added and concepts, such as modular design, code reusability, and API definition, need to be used as much as possible. In this work, we describe the software architecture developed for Walk-Man, a robot participant at the Darpa Robotics Challenge. The challenge required the robot to execute many different tasks, such as walking, driving a car, and manipulating objects. These tasks need to be solved by robotics specialists in their corresponding research field, such as humanoid walking, motion planning, or object manipulation. The proposed architecture was developed in 10 months, provided boilerplate code for most of the functionalities required to control a humanoid robot and allowed robotics researchers to produce their control modules for DRC tasks in a short time. Additional capabilities of the architecture include firmware and hardware management, mixing of different middlewares, unreliable network management, and operator control station GUI. All the source code related to the architecture and some control modules have been released as open source projects.

}, keywords = {Robotics}, doi = { http://dx.doi.org/10.3389/frobt.2016.00025}, url = {http://bit.ly/2jAPke2}, author = {M. Ferrati and A Settimi and L. Muratore and N. G. Tsagarakis and L. Natale and L. Pallottino} } @conference {2336, title = {Kinematic Analysis and Design Considerations for Optimal Base Frame Arrangement of Humanoid Shoulders}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA2015)}, year = {2015}, pages = {2710 - 2715}, address = {Seattle, USA, 25 - 30 May}, keywords = {Robotics}, doi = {10.1109/ICRA.2015.7139566}, author = {M. Bagheri and A. Ajoudani and J. Lee and D. G. Caldwell and N G Tsagarakis} } @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} } @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} } @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 {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 {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 {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} } @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 {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} } @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 {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 {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 {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 {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 {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 {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 {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} }