Robust fault-tolerant control for switched systems based on adaptive unknown input observer

This paper investigates the problem of fault diagnosis and fault-tolerant control in switched systems with actuator fault under unknown input disturbances. Initially, an adaptive unknown input observer capable of rapidly estimating faults was designed, incorporating proportional terms to enhance the response speed of fault estimation. Subsequently, by employing the average dwell time approach and using Lyapunov functions, the globally uniformly asymptotically stable of the error system under the $H_{\infty }$ performance index was proven. Following this, a state feedback controller was constructed using the state and error estimates from the observer, thereby guaranteeing closed-loop system stability even when faults occur. Finally, the effectiveness of the proposed method was validated through simulation examples.