Disturbance Observer-based Adaptive Fuzzy Fault-tolerant Tracking Control for Uncertain Nonlinear Systems with Input Delay and Actuator Faults

This paper investigates the design issue of the fault-tolerant tracking controller for uncertain nonlinear systems with input delay and actuator faults. Fuzzy logic systems are employed to approximate the uncertainties of the nonlinear systems. A state observer and a disturbance observer are designed to estimate the unmeasurable states and external disturbances, respectively. Moreover, an auxiliary system is applied to make up for the impact of the input delay. Furthermore, with the aid of the backstepping technology and the dynamic surface control method, a disturbance observer-based adaptive fuzzy fault-tolerant tracking controller is designed, which can guarantee that the output signal can track the reference signal greatly, and the other signals are bounded in the closed-loop system in case of input delay and actuator faults. Finally, a practical simulation example is supplied to demonstrate the effectiveness of the proposed method.