Mixed l -/l 1 fault detection observer design for positive switched systems with time-varying delay via delta operator approach

This paper investigates the problem of fault detection observer design for positive switched systems with time-varying delay via delta operator approach. A new fault sensitivity measure, called l (-)index, is proposed. The l (-) fault detection observer design and multi-objective l (-)/l (1) fault detection observer design problems are addressed. Based on the average dwell time approach and the piecewise copositive type Lyapunov-Krasovskii functional method in delta domain, sufficient conditions for the existence of such two kinds of fault detection observers are firstly given, and then the design methods are presented. Finally, two examples are provided to show the effectiveness and the applicability of the proposed methods.