脉冲MIG焊机优化控制

Control optimization for pulsed MIG weding machine

介绍了微机控制的脉冲MIG焊电源控制系统 ,比例 -积分 -微分 (PID)控制算法选择及系统控制软件的优化策略。针对脉冲MIG焊接过程中比例 -积分 (PI)控制和焊接参数实时显示的矛盾 ,在研究分析了PID控制算法的基础上 ,为实现实时采样控制和显示焊接参数 ,着重分析了串行显示芯片MAX72 19的工作时序 ,研究改进了MAX72 19的数据和命令格式的传输方式 ,以及在防止系统振荡的基础上对PID控制算法优化的方法。改进后PI控制时间仅为 80 μs,而进行 2 0 0次PI控制 (约 16ms)更新一位数码管 ,解决了频闪问题。试验结果表明 ,优化后程序执行效率高 ,响应速度快 ,控制精度高 。

A self-designed microcomputer control system for pulsed metal inert-gas(MIG) welding power source, the selection of proportional-integral-differential(PID) algorithms, and the optimization stratege of system conntrol software were introduod.To solve the conflict between proportional-integral (PI) control and real time display of welding parameters in MIG welding, the working Timing Diagram of serial display component MAX 7219 was analyzed, and the data and command transfer ways of it and the way to optimize PID control algorithms on the premise of avoiding system damping were improved.PI control time is only 80 μs and one bit digital display was refreshed every 200 times (about 16ms). The display flash problem was solved. The result showed that the optimized program run very fast, responded very quick, and was very accurate, and the welding proass was very stable.