焊接激光致熔池亚像素边缘提取方法研究  

Molten Pool Sub-Pixel Edge Calculation Method Caused by Laser Beam in Welding

作　　者：王邦国[1] 吴蒙华[1] 贾卫平[1] 

机构地区：[1]大连大学机械工程学院,辽宁大连116022

出　　处：《大连交通大学学报》2017年第3期51-54,共4页Journal of Dalian Jiaotong University

基　　金：辽宁省博士科研启动基金资助项目(20141121)

摘　　要：由于热变形等因素的影响,薄板激光焊接中焊缝会偏离预设轨迹,造成焊接激光束与焊缝偏离,使焊接质量下降.因此,焊接过程中要检测激光致熔池中心与焊缝偏差,并根据偏差量调整焊接位置.熔池中心由熔池边缘拟合求得,为精确获取熔池中心需要计算熔池的亚像素边缘.熔池亚像素边缘由以下步骤得到:(1)根据黑白CCD相机拍摄的图像中熔池灰度值大的特点,可初步确定熔池的中心;(2)以初步确定熔池中心为起点,在利用形态学方法得到熔池图像中搜索得到熔池像素级边缘;(3)在熔池图像中,提取以像素级边缘点为中心的一定区域像素灰度值,根据灰度值变化拟合曲线得到亚像素边缘.试验表明,所提出的方法能精确提取熔池亚像素边缘.The narrow area of the laser weld fusion zone is instrumental in realizing deep-penetration. However,small-focus wandering off seam caused by the thermal deformation will result in unacceptable welds.Therefore,the deviation between the laser-beam and the weld seam position needed to be detected during the welding process. In order to acquire the center of molten pool accurately,the sub-pixel edges of the molten pool should be calculated. The sub-pixel edges of molten pool are calculated in the follow procedures.（1）The initial center of the molten pool is obtained according to the gray value of the molten pool image which is acquired by monochrome CCD camera.（2）The morphology method is applied to acquire the pixel edge.（3） The sub-pixel edges of molten pool are calculated by curve fitting through employing the gray value of the pixels around the pixel edge point. Experiment shows that the proposed method can be applied to acquire the sub-pixel edge of molten pool.

关 键 词：激光焊接 视觉传感器 熔池 亚像素边缘 

分 类 号：TG456.7[金属学及工艺—焊接] TP391.41[自动化与计算机技术—计算机应用技术]