A Robust Direct Adaptive Fuzzy Control Algorithm

A robust direct adaptive fuzzy control scheme is proposed for a class of nonlinear systems with uncertainty.In this scheme,the equivalent control term is approximated by a fuzzy model,i.e.,the generalized fuzzy hyperbolic model(GFHM).Then,a robust compensation term is developed in form of hyperbolic tangent function to obtain a smooth control input without chattering phenomena.On conditions that the control gain of the system is known,partly known and unknown,it is proved by Lyapunov that the proposed control scheme can guarantee that the tracking errors converges at the small neighborhood of origin and that all variables involved are uniformly bounded.A simulation example is provided to demonstrate the effectiveness of the proposed control algorithm.