Global output feedback position regulation of friction robot manipulators

Abstract

This paper resolves the global output feedback asymptotic regulation problem of friction robot manipulators. A simple nonlinear switching proportional-derivative plus gravity compensation controller is proposed. Global asymptotic stability of the closed-loop system is shown with Lyapunov’s direct method. The conditions on controller gains ensuring global asymptotic stability are obtained herein in the form of simple inequalities on some well-known bounds of robot dynamics. Advantages of the proposed controller include the easy implementation and global asymptotic stability featuring faster transient and higher positioning precision. Simulations and experimental results demonstrate the effectiveness and the improved performance of the proposed control.