02174nas a2200229   4500008004100000022001400041245007300055210006900128260001200197300001200209490000700221520152100228653001301749100001801762700001601780700001501796700001701811700002001828700001701848700001501865856006401880       2017                        eng d  a1070-993200aControlling Soft Robots: Balancing Feedback and Feedforward Elements0 aControlling Soft Robots Balancing Feedback and Feedforward Eleme  c05/2017  a75 - 830 v243 a<p class="rtejustify">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—e.g., high-gain robust control, feedback linearization, backstepping, and active impedance control—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.</p>
10aRobotics1 aDella Santina1 aBianchi, M.1 aGrioli, G.1 aAngelini, F.1 aCatalano, M. G.1 aGarabini, M.1 aBicchi, A.  uhttp://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=793043801630nas a2200205   4500008004100000245008400041210006900125260003100194300001600225520091300241653001301154100001501167700001501182700002001197700001501217700001701232700001501249700001501264856014501279       2013                        eng d00aControlling the active surfaces of the Velvet Fingers: sticky to slippy fingers0 aControlling the active surfaces of the Velvet Fingers sticky to   aTokyo, JapancNovember 3-7  a5494 - 54993 a<p>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.</p>
10aRobotics1 aTincani, V1 aGrioli, G.1 aCatalano, M. G.1 aBonilla, M1 aGarabini, M.1 aFantoni, G1 aBicchi, A.  uhttp://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6697152&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6697152