Novel approach to design of a stable and robust fuzzy controller for a class of nonlinear systems

In this paper, the concept of variable structure system (VSS) with sliding mode was used to develop a fuzzy controller for a class of nonlinear system. The proposed sliding mode fuzzy controller (SMFC) preserves the fundamental property of sliding mode control that is stability and robustness in the presence of disturbances and model uncertainties. To reduce the number of design parameters in SMFC, we adopted the concept of parameterization or input-output mapping factor and devised a systematic tool for analyzing and enhancing the performance of SMFC. For demonstration, we applied the SMFC to the inverted pendulum problem. Simulation results indicates that the fuzzy sliding mode control perform well in the presence of disturbances and is insensitive to the parameter variation of the system.