Fault estimation and active fault tolerant control for servo systems

In this paper, the problems of fault estimation and fault tolerant control for motor servo systems are investigated. The motor servo systems are modeled as continuous-time linear systems with unknown inputs and actuator faults. Based on the faulty system model, a robust fault estimation and active fault tolerant control scheme is proposed. In this scheme, an observer-based robust fault estimator is designed to obtain the magnitude and characteristics of the faults; then, on the basis of the estimated fault information, an output feedback active fault tolerant controller is constructed to keep the post-fault dynamic system robust asymptotically stable. Simulation results illustrate the applicability and effectiveness of the proposed approach.