Design of adaptive fuzzy sliding mode for nonlinear system control

An adaptive fuzzy sliding mode controller (AFSMC) is proposed. The parameters of the membership functions in the fuzzy rule base are changed according to some adaptive algorithm for the purpose of controlling the system state to hit a user-defined sliding surface and then slide along it. The initial IF-THEN rules in the AFSMC can be randomly selected or roughly given by human experts, and then automatically tuned by a direct adaptive law. Therefore, the reduction of the expertise dependency in the design procedure of fuzzy logic control is called the rule tolerance property. By applying the AFSMC to control a nonlinear unstable inverted pendulum system, the simulation results showed the expected approximation sliding property, and the dynamic behavior of control system can be determined by the sliding surface