The Research Of Optimization Control Strategy In The Micro And Small Hole EDM

Electrical Discharge Machining is a new technology that use of electricity and heat directly.The technology will obtain higher surface quality, because there won’t produce the defect such as burr and mark grooves etc. This is because the tool electrode and workpiece is not direct contact, without the cutting force is generated in the process. In addition, EDM remove metal by pulse discharge, and tool electrode not only diversity, but also its size can reach micro grade compared with traditional mechanical cutting tool. Those advantages make EDM wide application in the field of micro machining widely and solve the difficult problems in micro hole machining effectively.Although the EDM can solve the machining of micro parts effectively, the machining efficiency is lower because it’s processing speed is slow. In addition, the complex of process and large number of parameters, lead to the control process is more complicated. When control of machining process improper, result in discharge process is unstable. It is producing arc or shot circuit, and declining the surface quality.At first, this paper analyze the micro hole EDM processing process parameters, aims to explore the main parameter that affects the surface quality and efficiency of EDM, eventually determines pulse width of pulse power is the main factor influencing EDM processing quality and efficiency, and put its as a system control volume of fuzzy control. This not only reduces the parameter variable in control process, reduced control difficulty, and pulse width can realize micro adjustment, so improve the response speed of the control system.This paper designed the two-dimensional fuzzy controller which use electrode voltage changes and rate of change of voltage as the input, pulse width in increments as the output. By fuzzy control rules to adjust the pulse width, keep the inter-electrode discharge state always stay in spark discharge status, guarantee the stability of electrode discharge. Combined with PID control at the same time, design the fuzzy-PID control system. When incremental change is small using PID control, achieve better steady-state performance. When incremental change is large selecting fuzzy control, achieve better dynamic performance.Modeling and simulation of MATLAB is a powerful feature, which not only can to simulate the system, and can be visualized modified parameters. It is will achieving more convenient and faster to adjust parameters. In addition, MATLAB can implement fuzzy logic operation in the system was quickly, can effectively improve the programs run. According MATLAB modeling and simulation analysis show that the fuzzy-PID control algorithm is superior to traditional signal control method. The volatility of the control system is lesser, and quickly restore balance and guarantee the stability of control system. This not only helps to ensure machining process can be steady, improve the efficiency of processing, and the stability machining process also provide a strong protection to improve the surface quality.