The Design Of Pulse Power Source And Servo Control System For Micro EDM

The micro-EDM technology is an important branch in the field of electrical discharge machining. It plays an irreplaceable role in many fields, such as narrow groove, deep hole, micro hole and other special processing field, because of the advantages of non-contact processing, precise and controllable discharge energy and high processing precision. So it has an extensive application in aerospace, electronics, precision machinery and other industries.The purpose of this paper is to design a micro energy pulse power source and a processing servo control system for the micro-EDM machine. Firstly, this paper introduces the principle of discharging and the process in micro EDM, and then introduces the particularity between micro EDM and the conventional EDM and analyzes the principle and process of the discharge in EDM, from the view of macroscopic and microcosmic. Besides, we research the key technologies, such as micro energy pulse power with high frequency, discharge condition detecting and servo control, meanwhile, this paper also analyze the solutions and research achievements according to the key technologies raised by many scholars, which providing a theoretical basis and designing reference for the following works of designing pulse power and processing servo control system.In order to meet the requirements of high-frequency and micro energy for discharging in micro EDM, we design a micro energy pulse power source with the advantages of high discharging frequency and controllable pulse energy, which uses a 32 bit high-speed STM32 MCU as the control core and uses controllable RC as discharge structure with power MOSFET. The power has the function of serial communication, that we can adjust processing parameters by computer. In addition, the power can detect the discharge state through the average voltage detection method, and upload the conditioned and conversed signal to the control system, in order to be the base of servo control.For the control requirements, high servo controlling precision, fast response speed, which the micro electrical discharge machining requirements, this paper adopts AC servo motor piezoelectric ceramic actuator to structure macro micro compound feed structure, ac servo implemented the feed or back movement with step away from. Piezoelectric ceramic actuator that carry on macro feed structure constitutes a micro feed grade, so implemented the controlling for the micro displacement and response to adjust. After the analysis of the combination of the two different control scheme, selecting the closed-loop servo piezoelectric actuator open-loop control mode. Ac servo system to realize position location, the micro feeding system is responsible for tiny displacement feeding and fast response.Then, we develop the MCU control system in the Real view MDK platform, and introduce the communication protocol between PC and MCU and the process of analyzing protocol. Besides we develop the host computer monitoring interface under the VC++ platform and servo control software with the motion control card supporting dynamic link libraries.