An improved stable and robust fuzzy controller for uncertain multivariable nonlinear systems

This paper presents the design of a stable and robust fuzzy controller for an uncertain multivariable nonlinear plant. The analysis is carried out by deriving a fuzzy plant model with parameter uncertainties for the plant. Based on the fuzzy plant model, three design approaches of the fuzzy controller are introduced to close the feedback loop. Then, stability and robustness of the closed-loop system is investigated. Stability conditions and robust areas which are less conservative than those reported previously are derived for each approach.