The Research Of CO₂ Arc Welding Digital Control System Based On DSP

CO₂ Arc Welding is a kind of high efficiency welding method with low cost. It iswidely used in mild steel and alloy steel all-position welding. But splash is a problemwhich prevents this method from being used on every condition. The waveformcontrol can decrease the splash effectively. Traditional control can't meet therequirements in precision, speed and stability. Therefore digital waveform control hasa great significance in CO₂ welding.The paper develops a digital control system for CO₂ arc welding. Based onTMS320LF2407, DSP minimum system, feedback circuit, A/D converter circuit,protection circuit, display circuit has been designed. This system also includeskeyboard input and LCD display for man-machine interaction. The PID control involtage and current feedback circuit has been simulated and the optimal parametershave been found. A particular time-sharing waveform control policy has been broughtforward. The model of CO₂ short circuiting transfer has been set up and the controlpolicy has been proved with the model. The code is produced by the Simulink modelwith the help of Embedded Target for TI C2000 DSP tool box, which is the first timefor using in the research of digital welding power source.The entire digital control system, including hardware, software and controlpolicy, has been proved in the stimulant experiments. The speed and accuracy of thissystem can meet the requirements of waveform control method.