Observer-based sliding mode control for switched stochastic systems under asynchronous switching

This paper is concerned with the observer-based sliding mode control (SMC) for switched stochastic systems with unmeasurable states under asynchronous switching. The state observers are designed to estimate the system states, and its switching legs behind that of the system. Based on the state estimate, the SMC problem is considered. First an integral type sliding surface is constructed and sufficient conditions for mean-square exponential stability of the closed-loop system are derived, even the observer switchings are asynchronous with those of subsystems. Variable structure controllers are designed to drive the state of switched systems to reach the sliding surface in finite time.