Fuzzy Adaptive Controller with Modulated Membership Function for a MIMO Uncertain Nonlinear System

An adaptive fuzzy controller for controlling a multi-input-multi-output uncertain nonlinear system is proposed in this paper. The controller design is observer based since not all the system states are measurable. The fuzzy adaptive controller with modulated membership function (FAC_MMF) modulates the fuzzy sets on both the consequent and antecedent parts by adjusting a few parameters. As searching for those parameters in modulated membership functions is done by micro-genetic algorithm, FAC_MMF becomes effective. Since all system experiences uncertainties, a robust controller and a supervisory scaling gain are implemented in a closed-loop nonlinear system to guarantee a stability condition established by Lyapunov function. Example of nonlinear systems controlled by the FAC_MMF is demonstrated to illustrate the effectiveness of the proposed method.