Fuzzy adaptive output tracking control of nonlinear systems

A stable adaptive fuzzy output tracking control scheme is developed for a single-input-single-output unknown nonlinear system. The main characteristics of the proposed adaptive fuzzy control are: i) it does not need the assumption that all the states of the system are available for full feedback, but introduces a high gain observer to estimate them; ii) it is composed of a robust control term and an equivalence fuzzy control so that it not only ensures the stability of the closed-loop system, but also attenuates the effect of fuzzy approximation error on the tracking error of the system to an arbitrary small level; and iii) it is proved that the designed output feedback adaptive fuzzy control can recover the performance achieved under the state feedback controller.