Fault detection and post-filter design for discrete-time switched systems with PDT switching

This paper investigates the fault detection and post-filter design issues for a class of discrete-time switched systems. The considered switching signals are of persistent dwell time characteristic, which are more general than the widely used average dwell time even dwell time switching properties. First of all, an observer-based residual generator is formulated, and the asymptotic stability of the augmented system is studied with the aid of semi-time-varying Lyapunov function approach, which derives the explicit expression of fault detection filters using the linear matrix inequalities technique. Then, a method of post-filter design is employed to improve the ability of fault detection, and the optimal residual evaluation is performed based on the typical parity-space approach.