Abstract: Filling of weld groove is a very important gist for welding parameters programming and regulating during longitude seam welding of spherical tank. According to the weld torch swing characteristic in multi-pass welding of spherical tank, a “quasi double cameras” stereovision (QDCS) sensor with a moving camera has been set up to detect the weld profile so as to avoid the conflict between public visual filled with double cameras sensors and the overlap of camera positions. Based on that, a particular algorithm has been developed to detect weld profile which could feature the filling of weld groove. The detection precision is no more than 0.5 mm, which could provide the basis for multi-pass welding control.

Key words: Detection, Multi-pass welding for spherical tank, One moving camera, Quasi double cameras stereovision sensor, Weld profile