Weld bead placement system for multipasswelding

A transputer-based laser triangulation vision system has been developed for use with automated tungsten inert gas (TIG) welding. The object of the vision system is to provide real-time seam tracking and weld bead profile monitoring at all stages of the multipass welding process to allow control of the welding process. The laser triangulation technique was used to measure the 3-D geometric profile in a single pass. The electronic image processing hardware was based on a vision system developed in-house by the University of Liverpool called the Transputer Image Processing System (TIPS). A prototype sensor system has been developed and used to track the position of the two corner positions of a V-preparation joint and to measure the weld profile between these positions as the multipass welding progresses. The concept and the design of the system are presented.