Robust Fault Detection Filter Design for Discrete Switched Linear Systems

A Robust fault detection filter(RFDF) is designed for discrete switched systems using H-/H_infinity performance index. Average dwell time constraints have been used for switching and the fault detection filter is designed with the assumption that the switching sequence is already known. RFDF is designed using the multiple Lyapunov function (MLF) approach. Projection lemma has been used for the purpose of decoupling the system state space matrices from the Lyapunov matrices so that separate Lyapunov functions can be used for meeting the two objectives simultaneously i.e. minimizing the effect of unknown inputs on the residual and maximizing the effect of faults on the residual signal.