激光精密焊接技术在焊点的精确定位以及焊接缺陷的实时检测方面还存在一些有待解决的问题。激光焊接过程会产生大量的等离子体, 严重影响机器视觉系统的成像质量。试验证明, 通过给机器视觉系统添加同轴辅助照明光源可实时获得清晰的熔池图像。在理想状态下, 激光焊接的熔池形状应为圆形, 根据这一特点设计了速度较快且准确度高的矩阵法进行熔池边缘的快速检测。利用圆拟合的方法在获得熔池中心坐标和半径的同时, 还可进行边缘缺陷的实时检测。

Although lasers are widely used for welding in precision engineering industry, it is still a challenge to achieve high accuracy in positioning welding spots with real-time defect detection. To obtain molten pool images without being disturbed by plasma radiation, a machine vision with coaxial auxiliary illuminant system was adopted. Under ideal conditions, the molten pool contour is a regular circle, and a new matrix algorithm can detect this contour quickly. The central position and radius of molten pool can be obtained with the utilization of circle fitting algorithm, and the edge defect can be detected at the same time.