Welding Penetration Control for Aluminum Pipe Welding Using Omnidirectional Vision-based Monitoring of Molten Pool

Abstract

This paper presents a study on a new method of welding penetration control for aluminum pipe in Tungsten Inert Gas (TIG) welding using omnidirectional vision-based monitoring of molten pool. As circumferential butt-welded pipes and the application of aluminum alloy in pipe welding that has been use in various industrial sectors requires new technique of welding monitoring process. For pipe welding using constant arc current and welding speed, the bead width becomes wider as the circumferential welding of small diameter pipes progresses. In order to avoid the errors and to obtain the uniform weld bead over the entire circumference of the pipe, the welding conditions should be controlled. This research studies the intelligent welding process of aluminum alloy pipe 6063S-T5 in fixed position using the AC welding machine. The monitoring system used an omnidirectional camera to monitor backside image of molten pool. A new method of image processing algorithm was implemented to process the captured image and to recognize the edge of molten pool. Back bead width as the result of detection was delivered into fuzzy inference system to control welding speed. From the experimental results it shows the effectiveness of the control system that is confirmed by sound weld of experimental results.