Fuzzy self-learning sliding mode control and its application to electro-hydraulic servo system

Based on integrating the property of sliding mode control (SMC) with the thought of variable universe in adaptive fuzzy controller, a design method of variable universe fuzzy self-learning sliding mode control (FSSMC) is proposed. By adjusting the universes of input variables and the membership functions of conclusion part in rules on-line, the high frequency chattering in the control input caused by sliding mode switching control can be effectively minimized, without sacrificing the strong robustness of SMC. Meanwhile, the goal of tracking control is obtained, and tracking precision is highly enhanced. Finally, the proposed control method is applied to the electro-hydraulic servo position tracking system. Simulation results verify the validity of the proposed approach.