Fault detection for linear switched systems using unknown input observers

The linear switched system is a kind of special hybrid system and composed of several continuous event subsystems and a switching signal. In the paper, the fault detection problem of switched system is addressed using unknown input observers (UIOs). First of all, parameters of UIOs are calculated through computing the inverse of system matrices and solving several linear matrix inequalities, which are obtained by applying the method of switched Lyapunov function. According to UIOs, residual generators are deduced for the purpose of detecting fault subsequently. Approaching the end of paper, a simulation example tests the effectiveness of proposed method.