Laser-vision-based quality inspection system for small-bead laser welding

Abstract

A laser-vision-based weld quality inspection system was developed and implemented for non-destructive weld measurement and defect detection. Our laser vision sensor module is designed based on the principle of laser triangulation. This paper summarizes our work on weld joint profile extraction, feature point extraction, weld bead size measurement, and defect detection. The configuration of the laser vision sensor is described and analyzed in detail, as well as the proposed image processing algorithms. A fast and reliable approach for detecting feature points on the laser stripe profile is proposed by using a sliding vector method. Weld joint modeling and dimension measurement methods are discussed in detail. The system allows the three-dimensional (3D) profile of the weld surface to be reconstructed in real time to allow weld monitoring and control, as well as post-weld quality inspection. Some experiments were implemented for size measurement and defect detection, using the laser-vision-based weld quality inspection system for small-sized beads. Experimental results show that the proposed system achieves highly accurate and satisfactory performance for real-time inspection requirements.