Adaptive process control in laser robotic welding

Abstract

An adaptive process control and seam tracking system for robotic laser welding with filler was developed and then evaluated for the butt welding of SS-1147 mild steel sheets of thickness 2 mm. The system comprises a 3 kW Nd:YAG laser, an industrial robot and a laser camera for seam tracking and measurement of gap width. The gap width data are used to control welding speed and wire feed rate. Experiments were carried out to weld butt joints of SS-1147 mild steel with gap widths varying between 0-0.8 mm. The resultant weld geometry was evaluated to determine the operating range of the laser camera (measured gap width) for monitoring to result in acceptable welds.