Adaptive Fault-Tolerant Control of Nonlinear Time-Delay Systems With Prescribed Performance

Abstract

An adaptive fault-tolerant control method considering actuator fault is proposed for a class of strict-feedback nonlinear time-delay systems. The prescribed performance is introduced by error transformation, which guarantees the transient performance of the system. Pade approximation and intermediate variables are used to eliminate the effect of input delay on the system performance. The universal approximation nature of fuzzy logic systems is used to approximate the unknown function in the system. A general fault model is introduced to describe the partial fault and stuck fault that may occur during the operation of the systems. The controller based on backstepping can ensure that the system operates normally with actuator fault. Through the Lyapunov function, all signals in the designed closed-loop system can be proved to be semi-globally uniformly ultimately bounded, and the tracking error can quickly converge to a compact set near the origin. Compared with the non-fault-tolerant control system, the simulation results show the effectiveness of the proposed control strategy.

Keywords

• Adaptive control
• fault-tolerant
• prescribed performance
• time-delay nonlinear system