Cartesian Impedance Control of Flexible Joint Robots: A Decoupling Approach

Download or read book Cartesian Impedance Control of Flexible Joint Robots: A Decoupling Approach written by Christian Ott and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work a Cartesian impedance controller for flexible joint robots was proposed. The control approach was based on the stability theory for cascaded systems. In the proposed controller an inner torque feedback loop decouples the torque dynamics from the rigid body dynamics. For the implementation of the impedance behaviour a control law well known from rigid body robotics is used in combination with the torque controller. It should also be mentioned that, apart from the considered impedance control problem, different rigid body controllers can be applied to the flexible joint model analogously to the procedure described herein. For the proof of the asymptotic stability of the closed-loop system one can take advantage of Theorem 2. Appendix In this appendix, a short lemma about uniform global boundedness of the solutions of time-varying differential equations is presented, which is used in Section 5.3 for the proof of uniform global asymptotic stability of the Cartesian impedance controller. Consider a time-varying system of the form (A.1) x = f ( x, t ) , with state x n . In order to show that the solutions of (A.1) are uniformly globally bounded (according to Definition A.1, which is taken from (Loria, 2001)), the following Lemma A.1 is usefull. This lemma can be proven easily based on the theorems presented in (Khalil, 2002).