一种新型等离子小孔焊接熔透闭环控制系统

建立了以电流和等离子体气流为控制变量的等子体小孔焊接熔透闭环控制系统，采用小波方法从焊接电弧电压信号中实时、准确地提取熔池穿孔信息，通过对2个参量的协调控制，成功地实现了“一脉一孔”的焊接工艺。实验表明，该系统不仅显著地提高了电弧穿透力，．能够有效地对10mm厚不锈钢进行小孔型焊接，而且具有良好的快速响应性能，成功克服了3－6mm厚度渐变及附跃变化带来的扰动，实现连续、稳定、可靠的较厚板穿孔焊接。

Novel penetration close-loop control system for keyhole plasma arc welding

A penetration close-loopcontrol system which taking welding current and plasma gas flow control as adjusting variables,has been established.Wavelet method has been used to detect penetration from arc welding voltage correctly in real-time.Through the sync control of welding current and plasma gas flow,the one-keyhole-per-pulse welding process has been realized successfully.Experimental results show that the system has increased penetrating force of plasma arc apparently and keyhole plasma arc welding has been successful in welding stainless steel with10mm thick.Moreover,the system possesses good response property,the disturbances from gradual change and break change from3mm to6mm thick have been come over,therefore the continuous stable and reliable keyhole plasma arc welding could be fulfilled in thicker steels.