棱形管与法兰角焊缝图像处理及特征提取

由于棱形管与法兰角焊缝的位置多变，且实际生产中棱形管端面加工精度不高，自动化焊接程度低，文中搭建了一套棱形管与法兰环焊缝的自动化焊接系统，对于提高棱形管与法兰焊接的自动化程度有较大的应用价值。该系统通过CMOS相机和单条纹激光组成激光视觉传感器，获取角焊缝位置和间隙信息。针对采集的图像及工件特征，设计了适合的图像处理算法，首先采用了灰度变换、均值滤波和形态学处理的方法对图像进行预处理，然后根据对激光条纹图像灰度值分析结果，寻找合适的阈值,并采用极值法提取光条中心点，最后采用霍夫变换拟合直线,提取出角焊缝位置信息，并提出激光条纹端点搜索方法，提取出了角焊缝间隙大小。结果表明，该图像处理方案效果较好，抗干扰能力较强，可以准确的提取出焊缝中心位置和间隙大小，满足焊接机器人对焊缝跟踪的要求以实现自动化焊接。 创新点： (1)设计出适用于棱形管与法兰角焊缝的自动化焊接系统。 (2)设计了适用于该系统的焊缝中心位置提取算法。 (3)设计了角焊缝间隙提取算法。

Image processing and feature extraction of fillet welds of prismatic pipe and flange

Due to the variable position of the fillet weld between the prismatic pipe and the flange, and the low machining precision of the end face of the prismatic pipe and the low degree of automated welding in actual production, a set of circular welding of the prismatic pipe and the flange is constructed in this paper. The automatic welding system of the seam has a great application value for improving the automation degree of the welding of the prismatic pipe and the flange. The system uses a CMOS camera and a single-stripe laser to form a laser vision sensor to obtain the position and gap information of the corner seam. According to the characteristics of the collected images and workpieces, a suitable image processing algorithm is designed. First, the methods of grayscale transformation, mean filtering and morphological processing are used to preprocess the images. Appropriate threshold value and extreme value method are used to extract the center point of the light stripe. Finally, the Hough transform is used to fit the straight line and extract the position information of the corner seam. The laser stripe endpoint search method is proposed to extract the size of the welding seam gap. The results show that the image processing scheme has good effect and strong anti-interference ability, and can accurately extract the center position and gap size of the weld, which can well meet the requirements of welding robots for welding seam tracking and realize automatic welding. Highlights: (1) Design an automatic welding system suitable for prismatic pipe and flange fillet welds. (2) Design an algorithm for extracting the center position of the weld seam for this system. (3) Design a corner seam gap extraction algorithm.