Adaptive fuzzy control of a class of pure-feedback nonlinear systems by output feedback

In this paper, adaptive fuzzy control is proposed for a class of nonlinear pure-feedback systems. Fuzzy logic systems are introduced to approximate the unknown nonlinear functions. The filtered signals are utilized to solve the algebraic loop problems encountered in the implementation of the usual controllers. Based on a newly developed approach that the observer gains can be assigned in an iterative manner the observer gains were obtained.An adaptive fuzzy output feedback backstepping control method is developed via the adaptive backstepping design. By employing Lyapunov synthesis, all the signals of the resulting closed-loop system are proven to be uniformly ultimately bounded by choosing the design parameters appropriately. Simulation results are provided to show show the effectiveness of the proposed approach.