Fuzzy sliding mode PI controller for nonlinear systems

In this paper, we present a fuzzy logic controller to combine sliding mode controller and PI controller for nonlinear systems with external disturbances. A sliding mode controller can give good transient performance and PI offer zero steady state error. However in the sliding mode controller, the steady state performance is poor due to the presence of discontinuous control action which causes chattering problem. Hence, combining these two controllers by a fuzzy logic can combine their advantages and remove their disadvantages. The proposed method can efficiently to eliminate the chattering in sliding phase so that high performance can be achieved. Some simulation results prove the validity of the proposed method.