Direct Adaptive Fuzzy Control of Nonlinear System Class with Applications

Abstract

In this article we propose a direct adaptive fuzzy control method for MIMO nonlinear plant encountered mainly in robotics. The fuzzy adaptive law ensures the stability, convergence of the controlled outputs, and "boundedness" of adaptation parameters. In this method, the approximation error of the fuzzy logic system is estimated by an adaptive law independently of external disturbances. Moreover, the fuzzy adaptive law incorporates a compensatory sliding term, which in turn depends on this estimated error. It leads to an adaptive compensation of approximation error. Simulations for cylindrical robot and induction motor are conducted to show the effectiveness of the proposed method.