01632nas a2200241 4500008003900000245006600039210006500105260004000170520094200210653001201152653001301164100001501177700001501192700001501207700001701222700001801239700001801257700002001275700001601295700001501311700001501326856004901341 2017 d00aDesign of an Under-Actuated Wrist Based on Adaptive Synergies0 aDesign of an UnderActuated Wrist Based on Adaptive Synergies aSingapore, 29 May-3 June 2017bIEEE3 a

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.

10aHaptics10aRobotics1 aCasini, S.1 aTincani, V1 aAverta, G.1 aPoggiani, M.1 aDella Santina1 aBattaglia, E.1 aCatalano, M. G.1 aBianchi, M.1 aGrioli, G.1 aBicchi, A. uhttp://ieeexplore.ieee.org/document/7989789/02408nas a2200241 4500008004100000245007300041210006900114260001200183520171500195653001201910653001301922100001801935700001601953700001501969700001501984700001401999700001302013700001802026700002002044700001602064700001502080856007102095 2017 eng d00aPostural Hand Synergies during Environmental Constraint Exploitation0 aPostural Hand Synergies during Environmental Constraint Exploita c08/20173 a

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.

10aHaptics10aRobotics1 aDella Santina1 aBianchi, M.1 aAverta, G.1 aCiotti, S.1 aArapi, V.1 aFani, S.1 aBattaglia, E.1 aCatalano, M. G.1 aSantello, M1 aBicchi, A. uhttps://www.frontiersin.org/articles/10.3389/fnbot.2017.00041/full01929nas a2200205 4500008003900000245012300039210006900162260003900231300001600270520124500286653001201531653001301543100001401556700001801570700002001588700001501608700001701623700001501640856006801655 2016 d00aSoftHand Pro-D: Matching Dynamic Content of Natural User Commands with Hand Embodiment for Enhanced Prosthesis Control0 aSoftHand ProD Matching Dynamic Content of Natural User Commands  aStockholm, Sweden, May 16-21bIEEE a3516 - 35233 a

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

10aHaptics10aRobotics1 aPiazza, C1 aDella Santina1 aCatalano, M. G.1 aGrioli, G.1 aGarabini, M.1 aBicchi, A. uhttp://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=748753201545nas a2200193 4500008003900000245007300039210006900112260004500181300001400226520093500240653001201175653001301187100001801200700001501218700002001233700001501253700001501268856006801283 2015 d00aDexterity augmentation on a synergistic hand: the Pisa/IIT SoftHand+0 aDexterity augmentation on a synergistic hand the PisaIIT SoftHan aSeoul, Korea, November 3 - 5, 2015bIEEE a497 - 5033 a
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.
10aHaptics10aRobotics1 aDella Santina1 aGrioli, G.1 aCatalano, M. G.1 aBrando, A.1 aBicchi, A. uhttp://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7363595