Robust fault detection filter design for a class of switched systems with time-varying delay

This paper studies the fault detection problem for a class of switched linear systems with time-varying delay. By using a switched observer-based fault detection filter as residual generator, the problem is formulated as an H_∞ filtering problem. Based on the average dwell time approach, new delay-dependent sufficient conditions for the existence of a robust fault detection filter (RFDF) are proposed. The minimal average dwell time and the corresponding filter matrices are obtained. A numerical example is provided to illustrate the effectiveness of the results.