01809nas a2200157   4500008004100000245011600041210006900157300001600226520122400242653001301466100001501479700001501494700001101509700001501520856011601535       2008                        eng d00aVSA-II: A Novel Prototype of Variable Stiffness Actuator for Safe and Performing Robots Interacting with Humans0 aVSAII A Novel Prototype of Variable Stiffness Actuator for Safe   a2171 - 21763 a<p>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.</p>
10aRobotics1 aSchiavi, R1 aGrioli, G.1 aSen, S1 aBicchi, A.  uhttp://95.110.227.16/publications/vsa-ii-novel-prototype-variable-stiffness-actuator-safe-and-performing-robots00977nas a2200145   4500008004100000245013700041210006900178260001000247520039500257653001300652100001700665700001100682700001500693856012300708       2007                        eng d00aVariable Impedance Actuations for Physical Human Cooperating Robots: a Comparative Analysis of Performance, Safety and Dependability0 aVariable Impedance Actuations for Physical Human Cooperating Rob  cApril3 a<p>An antagonistic actuation with variable stiffness is proposed for ensuring safety and performance in human friendly robotic applications. Various arrangements are analysed with respect to performance, safety and dependability. The results are expected to provide useful guidelines for choosing an actuation mechanism and its implementation for human-robot interactive applications.</p>
10aRobotics1 aFilippini, R1 aSen, S1 aBicchi, A.  uhttp://95.110.227.16/publications/variable-impedance-actuations-physical-human-cooperating-robots-comparative-analysis