@conference {3106, title = {Design of an Under-Actuated Wrist Based on Adaptive Synergies}, booktitle = {IEEE International Conference of Robotics and Automation, ICRA2017}, year = {2017}, publisher = {IEEE}, organization = {IEEE}, address = {Singapore, 29 May-3 June 2017}, abstract = {

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

}, keywords = {Haptics, Robotics}, doi = {10.1109/ICRA.2017.7989789}, url = {http://ieeexplore.ieee.org/document/7989789/}, author = {S. Casini and V. Tincani and G. Averta and M. Poggiani and C. Della Santina and E. Battaglia and M. G. Catalano and M. Bianchi and G. Grioli and A. Bicchi} } @article {3216, title = {Postural Hand Synergies during Environmental Constraint Exploitation}, journal = {Fronters in Neurorobotics}, year = {2017}, month = {08/2017}, abstract = {

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

}, keywords = {Haptics, Robotics}, doi = {https://doi.org/10.3389/fnbot.2017.00041}, url = {https://www.frontiersin.org/articles/10.3389/fnbot.2017.00041/full}, author = {C. Della Santina and M. Bianchi and G. Averta and S. Ciotti and V. Arapi and S. Fani and E. Battaglia and M. G. Catalano and M. Santello and A. Bicchi} } @conference {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} } @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} }