Abstract: Aimed at the torch departure from seam in TIG welding of copper-clad aluminum wire, a visual sensor for automatic weld seam tracking system is developed by initiative arc light. The image of copper plate opposite seam is taken 20 mm the front of the torch. In order to decrease the time of video signal processing, analog circuit is applied in the process where video signal is magnified, trimmed and processed into binary by the datum of developing average value. Therefore, the waveform of video signal of copper plate opposite seam is obtained. The method that is used for judging the direction of warp and estimating the value of warp between copper opposite seam and tungsten electrode is established. Results show that the method is feasible to identify copper opposite seam based on visual sensor. A reliable system to real-time tracking seam of copper-clad aluminum wire TIG welding can be provided. The response cycle of this system is no more than 60 ms, and the tracking precision is less than 0.1 mm.

Key words: Automatic tracking, Copper-clad aluminum wire, TIG welding, Visual sensor