Research And Application Of Intelligent Control Of Electro-hydraulic Servo System In Electric Discharge Machining (EDM) Process

In this dissertation, the control methods of electro-hydraulic servo system was used in incising of irradiation monitoring pipe by EDM, according to demand of maintaining the reactor internal components. We cannot get good performance when using routine PID controller because there are so many troublesome problems such as time-variable parameters, outside disturbance and the nonlinear dead zone of the valve existing in the electro-hydraulic position servo control system. It is well known that it is not necessary to get an accurate model of the system for a fuzzy controller, which has stronger adaptability to the process parameter variations. Therefore, we adopt fuzzy controller to control the electro-hydraulic position servo system, which has great practical significance and theoretical value.The characteristics and applications of hydraulic servo systems and fuzzy control theory are summarized firstly in this dissertation. In connection with the characteristics of conventional PID controller and fuzzy controller, a new type fuzzy PID controller with parameter adaptation is explored in studying the control problems of the EDM process. By selecting the control parameters of the self-adaptive fuzzy control system in the EDM process and the linguistic variables of the controller, defining the membership function of the fuzzy subsets and the fuzzy control rule of the controller, establishing the correction quantity polling list for the PID controller parameters and studying self-adjusting problem of quantitative factors and proportionality factors of the control system, a new type fuzzy PID controller with parameter adaptation has been designed to reapplied in the EDM process. Simulation results of the designed controller show that the electro-hydraulic position servo system designed in this dissertation has...