01804nas a2200193   4500008004100000245012300041210006900164260003900233300001400272520106400286653002101350653004401371653001301415100001601428700001401444700001501458700001501473856012201488       2009                        eng d00aNonlinear Decoupled Motion-Stiffness Control and Collision Detection/Reaction for the VSA-II Variable Stiffness Device0 aNonlinear Decoupled MotionStiffness Control and Collision Detect  aSt. Louis MO USAcOctober, 11 - 15  a5487-54943 a<p>Variable Stiffness Actuation (VSA) devices are being used to jointly address the issues of safety and performance in physical human-robot interaction. With reference to the VSA-II prototype, we present a feedback linearization approach that allows the simultaneous decoupling and accurate tracking of motion and stiffness reference profiles. The operative condition that avoids control singularities is characterized. Moreover, a momentum-based collision detection scheme is introduced, which does not require joint torque sensing nor information on the time-varying stiffness of the device. Based on the residual signal, a collision reaction strategy is proposed that takes advantage of the proposed nonlinear control to rapidly let the arm bounce away after detecting the impact, while limiting contact forces through a sudden reduction of the stiffness. Simulations results are presented to illustrate the performance of the overall approach. Extensions to the multi-dof case of robot manipulators equipped with VSA-II devices are also considered.</p>
10aEmbedded Control10aPhysical Human-Robot Interaction (pHRI)10aRobotics1 aDe Luca, A.1 aFlacco, F1 aSchiavi, R1 aBicchi, A.  uhttp://95.110.227.16/publications/nonlinear-decoupled-motion-stiffness-control-and-collision-detectionreaction-vsa-ii01543nas a2200229   4500008004100000245009900041210006900140260002000209300001200229520078400241653002101025653001301046100001501059700001601074700001601090700001701106700001701123700001601140700001801156700001601174856012301190       2004                        eng d00aOn The Problem of Simultaneous Localization, Map Building, and Servoing of Autonomous Vehicles0 aProblem of Simultaneous Localization Map Building and Servoing o  bSpringer Verlag  a223-2393 a<p>In this chapter, we consider three of the main problems that arise in the navigation of autonomous vehicles in partially or totally unknown environments, i.e. building a map of the environment, self-localizing, and servoing the robot so as to achieve given goals based on sensorial information. As compared to most part of the existing literature on SLAM, we privilege here a system-theoretic view to the problem, which allows the localization and mapping problems to be cast in a unified framework with the control problem. The chapter is an overview of existing results in this vein, and of some interesting directions for research in the field. All chapters of this volume were revised and published online March 2005. The volume number was corrected from 4010 to 10.</p>
10aEmbedded Control10aRobotics1 aBicchi, A.1 aLorussi, F.1 aMurrieri, P1 aScordio, V G1 aSiciliano, B1 aDe Luca, A.1 aMelchiorri, C1 aCasalino, G  uhttp://95.110.227.16/publications/problem-simultaneous-localization-map-building-and-servoing-autonomous-vehicles.html