Development of laser stripe sensor for automatic seam tracking in robotic tailored blank welding

This paper describes the development of laser stripe sensor for automatic seam tracking system in robotic tailored blank welding. Laser stripe sensor which is used to obtain profile of weld seam plays an important part in seam tracking system. The sensor consists of a CMOS camera based on FPGA (field programmable gate arrays) and a stripe-type laser diode due to high speed requirement of tailored blank welding. Its measuring error and performance make a direct effect on the measuring accuracy and reliability of the seam tracking system. A mathematic model is established in order to analyse the influence on sensor error from the geometric parameters. And then the reasonable geometric parameters are yielded according to the simulation results. Additionally, careful considerations about laser diode have been under taken in this paper in order to obtain high quality raw images of laser stripe and the feature points for seam tracking of robot manipulation are calculated by feature extracting algorithm. Finally, some experiments are carried out for proving the efficiency of the laser stripe sensor.