Robust indirect adaptive fuzzy control

This paper proposes a robust indirect adaptive fuzzy controller that can be applied for tracking control of a class of uncertain nonlinear SISO systems. It is shown that, in the presence of the perturbations such as external disturbances and approximation error of the fuzzy logic system, boundedness of all the signals in the system is ensured, while under the assumption of no perturbations, the stability of the overall system is guaranteed. The concept of persistent excitation in the adaptive fuzzy control systems is utilized to guarantee the convergence and the boundedness of adaptation parameters in the proposed controller. Simulation is conducted to show the effectiveness of the proposed controller.