A general practical design method for fuzzy PID control from conventional PID control

Proposes a practical design method of fuzzy proportional-integral-derivative (PID) control system. Like conventional PID controllers there are several kinds of fuzzy PID controllers. Being simple structure, the research on how to choose the type of conventional PID controllers for different controlled plants is successful. Based on the analysis of relationship between conventional PID controller and fuzzy PID controller, we propose a method on how to choose the type of fuzzy PID controller suitable for the controlled plant. Firstly the selected fuzzy PID controller is designed to have the same control property with corresponding PID controller because the parameters of its control rule base are calculated according to tuned parameters of the PID controller. Then parameters of this fuzzy rule base of fuzzy PID controller are tuned by a sequential quadratic programming algorithm. The tuned control surface is nonlinear corresponding to the property of controlled plant. This method is applied to linear and nonlinear controlled plants. Simulation results show that it is an effective method for designing fuzzy controllers.