A specific structuring element-based opening method for rapid geometry measurement of weld pool

Abstract

This paper focuses on measuring weld pool geometry by removing interferences overlapped with the weld pool region in images. The images come from a vision system observing deep penetrate CO2 laser welding. The measurement is achieved through computer vision. First, Otsu’s method is used for threshold processing to get the binary image. Second, morphological opening with a specific structuring element is used to remove interferences and recover the weld pool. This method is called specific structuring element-based opening (SSEO). It effectively eliminates interferences like spatter, arc light, and plasma to obtain the accurate weld contour. The accurate contour is then used to calculate precise geometry parameters. The SSEO method is also efficient enough to satisfy the real-time requirements.