Adaptive fuzzy output feedback backstepping control of pure-feedback nonlinear systems via dynamic surface control technique

摘要

In this paper, an adaptive fuzzy backstepping dynamic surface control approach is considered for a class of uncertain pure-feedback nonlinear systems with immeasurable states. Fuzzy logic systems are first employed to approximate the unknown nonlinear functions, and then an adaptive fuzzy state observer is designed to estimate the immeasurable states. By the combination of the adaptive backstepping design with a dynamic surface control technique, an adaptive fuzzy output feedback backstepping control approach is developed. It is proven that all the signals of the resulting closed-loop system are semi-globally uniformly ultimately bounded, and the observer and tracking errors converge to a small neighborhood of the origin by choosing the design parameters appropriately. Simulation examples are provided to show the effectiveness of the proposed approach.