Adaptive Fuzzy Controller Design Of Switched Stochastic Nonlinear Systems

In recent years, switched stochastic nonlinear systems has been a hot study problem in control area both in theory and applications. Although considerable attention has been paid to such systems, there are still many problems to be further studied. By backstepping and adaptive fuzzy control technique, this dissertation discusses the feedback control problem for several classes of switched stochastic nonlinear systems, and studies the boundedness of the closed-loop systems. The main contents are as follows:1. For a class of output-constrained switched stochastic nonlinear systems, a well-designed nonlinear mapping is introduced to transform the system to an unconstrained one. By utilizing backstepping technique and fuzzy logic systems, the constructed controller guarantees all the closed-loop signals remain bounded without violating the constraint. Simulation results verify the effectiveness of the obtained results.2. For a class of switched stochastic nonlinear time-delay systems, a suitable reduced-order observer is presented to estimate the unmeasurable system states, and an appropriate stochastic Lyapunov–Krasovskii functional is chosen to deal with the time-delay terms, then a controller is proposed via backstepping technique and fuzzy logic systems, which ensures the boundedness of all the closed-loop signals. Simulation results verify the effectiveness of the developed method.3. For a class of switched stochastic nonlinear systems in low-triangular form, a switched observer is introduced to estimate the unmeasurable system states. A controller is proposed with the help of backstepping and dynamic surface control technique, which ensures the boundedness of all the closed-loop signals associated with average dwell time approach. Simulation studies further verify the effectiveness of the proposed control design.