The Research of Adaptive PID for the Thin-Walled Cylinder TIG Welding Penetration Control

The fluctuations of process parameters and groove dimensions would lead to the change of weld penetration state in the thin-walled cylinder girth weld, the penetration state was need to detect and control real-time in order to ensure stable penetration. A vision-based direct sensing method was established for thin-walled cylinder TIG weld, the clear back pool image was got, the wide range back melt pool of penetration requirement have been got by the image process, the penetration state could be controlled by self-tuning PID controller adjusting welding speed adaptively. The results showed that the penetration signal extracted by this method was reliable, virtually eliminating the control blind area caused by indirect sensing method.