Study Of Servo Control System On Electric Discharge Machining Based On Visual C++

Electric Discharge Machining (EDM) is a new type of nontraditional machining and has been developing for a few decades. Now EDM is heading towards high efficiency, high accuracy and intelligence. The EDM is used for machining super-hard conductive materials, especially for the cutting tool or mold fabrication. With the rapid development of science and technology, the urgent requirements for the hard-to-cut materials were proposed. Therefore the main task of this paper is to develop a new NC system base on PC and a new servo system for improvement of the present EDM machine tool.In this paper, EDM theory was firstly analyzed according to the documentation mainly, and the mechanism of EDM was then discussed. The effective factors of EDM process has been studied. These works pave the way for setting up a new servo system.In this paper, a servo control system is designed based on fuzzy control technology, and then a fuzzy control algorithm with parameter adaptation is presented. The self-adaptive fuzzy control system is composed of two part: fuzzy controller (FC) and parameter adjuster. The input parameters of the fuzzy controller include the error and error change of short circuit-discharge arc rate, the error and error change of on discharge rate, and the output is the feed frequency of motor. Furthermore, a parameter adjuster with two input: error and error change of discharge rate, is developed to adjust proportionality factors of the FC. The presented fuzzy control method with parameter adaptation has higher machining rate and better adaptability and stability compared with traditional adaptive control used in EDM.In order to perform the machining process with higher efficiency and stability, a new NC system based on PC and a motion control card were established. This card was based on PC ISA bus. Through this control card, PC can connect CUP with external signals and exchange information easily. The new NC system developed by Visual C++ can control the machining process automatically.