Indirect adaptive fuzzy control for a class of strict-feedback nonlinear systems with time-varying dead-zone

Abstract

An indirect adaptive fuzzy control scheme is developed for a class of uncertain strict-feedback nonlinear systems. The fuzzy approximators are used to design an adaptive fuzzy controller and an adaptive fuzzy identification model, and the unknown parameters are adjusted by the modeling error,the tracking error and its time-varying dead-zone. The size of time-varying dead-zone is adjusted adaptively with the estimated bounds on the approximation errors. Furthermore, the proposed design scheme guarantees that all the signals in the resulting closed-loop system are bounded, and the tracking error converges to a small neighborhood of the origin. Finally, a simulation example is used to demonstrate the effectiveness of the proposed control scheme.