Observer-Based Adaptive Fuzzy Control for a Class of Nonlinear Delayed Systems

This paper considers the problem of observer-based adaptive fuzzy control for a class of nonlinear time-delay systems in nonstrict-feedback form, which includes the nonlinear strict-feedback systems as a special case. An adaptive fuzzy output feedback backstepping approach is first proposed for nonlinear systems in nonstrict-feedback form. Fuzzy logic systems are used to approximate the unknown nonlinear functions. Adaptive technique and backstepping are utilized to construct a controller. The proposed adaptive fuzzy output feedback controller guarantees that all the signals in the adaptive closed-loop system are semi-globally uniformly ultimately bounded. Simulation results are provided to demonstrate the effectiveness of the presented approach.