Observer-based feedback passification of a class of switched fuzzy systems

This paper is concerned with the issue of feedback passification for switched fuzzy systems through the multiple Lyapunov functions method. Since the system state is often unavailable, we design observers and observer-based controllers for each fuzzy subsystem of such a switched fuzzy system. A switching law depending on the observer state is designed which, together with the control law can render the switched fuzzy system passive even each fuzzy subsystem is not feedback passive. Passivity conditions for the switched fuzzy system are derived in terms of matrix inequalities. Finally, a numerical example is presented to demonstrates the effectiveness of the proposed method.