Study on Stereo Vision for 3D Reconstruction of Welding Seam

Abstract

The Monocular stereo vision sensor based on structured light is designed and invented for the detection of the weld seam. By incorporating the structured light, the corresponding points matching problem in the stereo vision has been solved effectively. Firstly, the built monocular stereo vision system is used to obtain the image information of seam surface. Then the image coordinate of the seam feature points in the two-dimensional plane can be identified and extracted, through the responding image processing and feature analysis of the seam image collected. After that, the three-dimensional coordinates are calculated by using the theory of projective geometry according to the positional relation between the CCD camera and structured light projected in the seam surface. By this way, the seam feature information such as the three-dimensional geometry sizes, the groove type, the angle, and the interval can be obtained. Finally, the algorithm performance is tested by the experiment of obtaining the three-dimensional coordinate for seams center points, and the results have proved the detection accuracy and reliability of the visual collection system.