Adaptive Fuzzy PI Prescribed Performance Tracking Control for Switched Nonlinear Systems With Dead-Zone Input and External Disturbances

This paper studies the problem of adaptive fuzzy proportional-integral (PI) tracking control for a class of switched nonlinear systems with dead-zone input, unknown nonlinear functions and external disturbances. By using backstepping method with fuzzy logic systems, a set of adaptive fuzzy PI tracking controllers are proposed, which have a simple structure and a clear physical meaning. The designed controllers don't need priori information of dead-zone input via introducing Nussbaum function scheme. To enhance the tracking performance, the prescribed performance technique is utilized to constrain the tracking error. The stability analysis of the closed-loop switched systems is established via common Lyapunov function, and the tracking error remains within a prescribed bound and all signals of the closed-loop system are bounded. Finally, the effectiveness of the scheme is verified by two examples.