Fault-tolerant adaptive PID switched control of robot manipulator based on average dwell time

Abstract

The multi-mode tracking control of robot manipulators with unknown dynamics is investigated in this paper. In view of varying loads, robot manipulators are modeled as multi-mode switched systems. Adaptive PID (proportion–integration–differentiation)–like switched controllers are designed via the error transformation and multiple Lyapunov function method, which can make the error system practical stability within prescribed time under a class of switching signals satisfying average dwell time. Furthermore, two cases under the healthy actuator and faulty actuator are discussed. For the case of the partial failure of the actuator, the fault-tolerant adaptive PID-like controller is presented, which consists of two parts. Finally, a simulation example is given to demonstrate the effectiveness of the proposed method.