Output Feedback Passification of Saturated Switched Systems Under the Improved State-Dependent Switching

This paper focuses on the passivity analysis and feedback passification of discrete-time switched systems with actuator saturation. The proposed framework consists of a switching law and a bank of time-varying output feedback controllers. The switching law is depending on partial state measurements and switching-delay slack matrix, which avoid the possible too frequent switching caused by the classical state-dependent switching law. The resulting time-varying saturated controllers associated with the switching law are constructed to guarantee the passivity of the closed-loop systems. In addition, the performance index measuring the level of unknown input tolerance capacity of the systems can be also estimated. Sufficient conditions for the existence of the switching law and controllers are provided via Lyapunov–Metzler inequalities. Finally, the effectiveness of the theoretical results is illustrated through an example derived from the stirred tank reactor.