A hybrid of fuzzy and fuzzy self-tuning PID controller for servo electro-hydraulic system

Because of the existing hybrid fuzzy PID controller does not perform well when applied to servo electro-hydraulic system (SEHS). Forasmuch, when the system parameters changes will require a new adjustment variable of PID controller. Therefore, a hybrid of fuzzy and fuzzy self-tuning PID controller is proposed in this paper. The proposed control scheme is separated into two parts, fuzzy controller and fuzzy self-tuning PID controller. Fuzzy controller is used to control systems when the output value of system far away from the target value. Fuzzy self-tuning PID controller is applied when the output value is near the desired value. In the terms of adjusting the PID parameters are tuned by using fuzzy tuner as to obtain the optimum value. We demonstrate the performance of control scheme via experiments performed on the motor speed control of the SEHS. The results from the experiments show that the proposed a hybrid of fuzzy and fuzzy self-tuning PID controller has superior performance compared to a hybrid of fuzzy and PID controller.