Direct adaptive fuzzy PI sliding mode control for a class of uncertain nonlinear systems

A stable direct adaptive fuzzy PI sliding mode controller for a class of nonlinear uncertain systems is investigated. The proposed method is robust in the presence of uncertainties and bounded external disturbances. Considering other existing approaches of handling external disturbances, the proposed approach does not need a bound to be known; only requiring that it exists. Moreover, the PI control structure is used for attenuating chattering problem. The approach is applied to a nonlinear system as well as a chaotic nonlinear system via significant disturbances. Analysis of simulations reveals the effectiveness of the proposed method.