Joint tracking controller for multi‐link flexible robot using disturbance observer and parameter adaptation scheme

Abstract

Abstract An improved composite controller of singular perturbation approach is designed for controlling a multi‐link flexible robot with uncertainties. We adopt the standard form of a singular perturbation approach for modeling. To reduce the coupling effect from flexibility, the bandwidth of a slow subsystem is modulated by considering the fundamental frequency. The disturbance observer provides a means for defining the bandwidth of a slow subsystem as well as compensating disturbances. At the same time, uncertainties in the fast subsystem are updated to enhance the capability for vibration suppression in conjunction with PID (Proportional‐integrative derivative) modal feedback. We draw conditions for Lyapunov stability of the modal feedback and adaptive scheme. A numerical simulation will support the validity of our research results. © 2002 Wiley Periodicals, Inc.