Precompensation for a hybrid fuzzy PID control of a proportional hydraulic system

While classical PID controllers are sensitive to variations in the system parameters, fuzzy controllers do not need precise information about the system variables in order to be effective. However, PID controllers are better able to control and minimize the steady state error of the system. Hybridization of these two controller structures comes to one mind immediately to exploit the beneficial sides of both categories. Nevertheless, a hybrid fuzzy PID controller does not perform well when applied to Proportional Hydraulic System (PHS) containing nonlinearities arising from unknown deadzones. To enhance the controller performance for the PHS with deadzones, in this paper, precompensation of a hybrid fuzzy PID controller is proposed. The proposed control scheme consists of a fuzzy logic-based precompensator followed by fuzzy controller and PID controller. We demonstrate the performance of scheme via experiments performed on a PHS position control. Our results show that precompensation of a hybrid fuzzy PID controller have superior performance compared to a conventional hybrid fuzzy PID controller.