Abstract: By considering the special characteristics of an unknown disturbance and an unknown plant of single-input/output nonlinear variable structure systems, based on the fuzzy adaptive controller, a new method with the projection function for controlling the variable structure is presented. ecause the method can track satisfactorily all types of state of a class of uncertain variable structure systems, it can extend the nonlinear state error feedback control law(NLSEF) and auto disturbance rejection controller(ADRC) application field. Furthermore, the proof of the stability of the method is made mathematically. Finally, three examples are given to demonstrate the method.

Key words: nonlinear systems, fuzzy adaptive, output feedback