Research On Intelligent Control Method Of Magnetic Actuator For Micro EDM

Electric discharge machining does not require the strength and hardness of conductive materials,and it is a non-contact special machining method.With its unique processing advantages,EDM technology plays an important role in the fields of aviation equipment,electronic instrumentation,and medical engineering.Aiming at the problems of untimely positioning of the micro-EDM in the axial direction,instability of the electrical pressure of the inter-electrode machining,and the inability to discharge inter-electrode debris products,the processing cannot be performed normally.In this thesis,a non-linear,fast response,broadband,and high-precision magnetic actuator is used as a local actuator of micro-EDM,and intelligent control technology is used to control the control system of the micro EDM magnetic driver to drive the tool electrode in the axial direction.The direction is fast and micro-positioned,so that the discharge gap is maintained within the effective discharge range.Firstly,the EDM process and its principle are introduced,and the structure and working principle of the magnetic actuator are researched and analyzed.In order to realize the real-time detection of machining status,the gap average voltage detection circuit is designed by using a step-down circuit and a low-pass filter.Aiming at the feasibility of application of the magnetic actuator in micro-EDM,the linear mathematical model of the magnetic actuator is established using the mechanical balance equation,and the displacement control simulation and experiment of the magnetic actuator based on PID control are carried out,which verifies that the magnetic actuator has fast response,observability and controllability.Secondly,through in-depth study of the control method of the micro-EDM magnetic actuator control system,the fuzzy control is introduced into the conventional PID control to realize the online real-time tuning of the control parameters of the PID control and improve the dynamic and static performance of the control system.Aiming at the limitation that the quantization factor and scale factor of fuzzy PID control cannot be changed once they are set,a variable universe fuzzy PID controller is designed by combining fuzzy PID control with universe adjusting mechanism based on fuzzy reasoning.By adjusting the expansion and contraction of the initial universe of fuzzy PID control,the control accuracy and adaptive ability of the control system are enhanced.Finally,in order to verify the superiority of micro-EDM magnetic actuator control system based on variable universe fuzzy PID control,MATLAB/Simulink is used for simulation analysis,and at the same time,experimental analysis is carried out on three aspects of discharge state,machining efficiency and machining surface quality.Simulation and experimental results show that the control effect of the variable universe fuzzy PID control is better.Compared with the traditional EDM machine,the machining efficiency of the variable universe fuzzy PID control magnetic actuator and the traditional EDM machine cooperative control is increased by 40%,and the machining process is more stable,and the processing surface quality is better.