冷轧带钢激光拼焊的焊缝在线检测研究

焊缝质量在线检测是冷轧带钢激光拼焊过程中的重要关键技术之一。为了解决武钢TRUMPF12000 轴快流激光拼焊设备在焊接过程中出现的错边、拼缝、焊缝形态等问题,采用3个传感器分别采集焊前间隙图像信息、焊接过程图像信息以及焊后焊缝图像信息,利用OTSU 自动计算图像阈值、运用投影矩阵的方法将图像坐标转换到工件坐标,编写程序提取图像特征点的方式建立焊缝质量在线检测系统,并以5m/min焊接速率对3mm厚冷轧板进行焊接实验,测量焊接试样焊缝宽度相对误差在4.42%左右。结果表明,焊缝质量检测系统可以计算出较为准确的焊缝宽度、焊缝错边量等信息。

Research of on-line inspection of laser welding seam quality of cold rolled strips

On-line inspection of seam quality is one of the most important key technologies in laser welding of cold rolled strips. In order to solve the welding problems of TRUMPF12000 fast-flow axial laser welding equipment used in WISCO, such as misalignment,seam and weld morphology, three sensors were adopted to acquire image information including gap images before welding, penetration images during welding, and seam images after welding and so on. OTSU operation was used to find the threshold automatically. Projective geometry was used to convert image coordinates to workspace coordinates. Codes were written to extract image features. On-line seam quality inspection system was founded. Experiments were performed to test the inspection accuracy of 3mm thickness cold steel at weld velocity of 5m/min. The relative error of seam width was about 4.42%. The results show that the seam inspection system can offer the accurate judgment comparatively.