Analysis and Design of a Nonlinear Robust Controller

Abstract

A nonlinear controller and its design method are proposed. The development of the controller is motivated by fuzzy control. The controller has the advantages of simple structure, rapid computation, zero steady error, few parameters to set, and robustness to structure uncertainties and to parameter variations. Comparing the new controller with the PID controller, we find the performance of the new controller to be better. Its sensitivity to variations of the system is smaller than that of the PID and it requires no prefilter to avoid large overshoot. Digital simulations are performed to verify the capability of the proposed new nonlinear controller.