Measurement of Bead Width Using Feedback Control During Welding Speed Change in TIG Welding

TIG arc welding is a technique to melt and join base metal with heat input using arc discharge. This technology has the advantages of no spatter during the welding, welding in all positions, and applicability to all joint shapes. In recent years, with the decrease in the number of skilled workers, the digital twin of TIG arc welding has been desired. However, the automation cannot be applied to the distorted base metal. Therefore, in this research, as a first step of digital twin, a drone camera was used to capture the arc shape, and feedback control was performed using a Raspberry Pi. Specifically, TIG arc welding was automated by taking pictures of the arc state, sending them to the Raspberry Pi, extracting only the arc state using OpenCV, measuring the arc length from the arc state, and automatically controlling the distance between electrodes. As a result, the bead width was observed using feedback control during welding speed change in TIG welding.