Fixed-Time Fault Estimation and Prescribed Performance Fault-Tolerant Control for Interconnected Systems
针对同时存在乘性和加性执行器故障的互联系统，提出了一种固定时间故障估计观测器和基于预设性能函数与递归快速终端滑模的主动容错控制方法，能在指定时间内精确估计故障并保证跟踪误差固定时间收敛。
This article investigates the problem of fixed-time fault estimation and fault-tolerant control (FTC) for interconnected systems subject to both multiplicative and additive actuator faults. On the basis of the bilimit homogeneous theory, the proposed fault estimation observer can acquire the exact system state and fault information in a specified time, and such a time is determined by a constant upper bound, independent of the initial observation errors. Next, the prescribed performance function (PPF) is employed to impose the anticipant performance criterion on the trajectory tracking errors, for the purpose of preserving both desirable transient and steady-state responses. Afterward, we incorporate the recursive fast terminal sliding-mode technique into the active FTC (AFTC) design procedure to eliminate the influence of faults. In such a way, the fixed-time convergence property of tracking errors can be guaranteed without any restriction on the initial conditions. Finally, comparative simulation results are provided to illustrate the feasibility and superiority of the proposed strategy.