Fixed-Time Fuzzy Adaptive Fault-Tolerant Control for Strict-Feedback Nonlinear Systems With Input Delay

This article aims to investigate the problem of fixed-time fuzzy adaptive fault-tolerant tracking control for strict-feedback nonlinear systems (SFNSs) suffering from actuator fault and input delay. In practical engineering applications, actuator fault and input delay are two common problems, which are easy to affect system performance and cause adverse consequences. To rapidly deal with these two problems, a fixed-time fuzzy adaptive fault-tolerant control (FTC) algorithm is proposed. Specifically, fuzzy logic systems (FLSs) and Pade approximation method are applied to address the unknown nonlinearity and the input delay issues, respectively. Besides, command filter technique is applied to replace the traditional backstepping method to eliminate "complexity explosion" issue in calculation process. Under the role of fixed-time controller, the effects of input delay and actuator fault are rapidly suppressed, and the controlled system can obtain the better control performance on convergence speed and steady-state error. The comparative simulation examples demonstrate that the controller utilizing fixed-time stability has better control and fault tolerance performance, thus verifying the superiority of the proposed method.