Real-time welding process control using infrared sensing

The thermal distribution changes associated with gas tungsten are welding process were studied to identify and correct for weld joint offsets for butt joints. These changes were experimentally measured using infrared thermography. In the weld offset conditions the slope of the temperature distributions were found to be altered dramatically. Not only did offset produce asymmetric temperature distributions but a steep increase in gradients was also observed. These changes were then used to detect and correct initial errors in the position of the torch during the welding of straight and curved contours of perfectly fitted butt joints and joints with gap.