基于同轴视觉传感的激光穿透焊接焊缝尺寸检测

Detection of weld dimension in open keyhole laser welding based on a CMOS coaxial visual sensing system

利用CMOS同轴视觉传感系统,通过分析匙孔和熔池区域光辐射的特征,对Nd∶YAG激光深熔焊接的焊缝形态进行了检测。结果表明,在匙孔穿透型激光深熔焊接中,匙孔在工件背面穿透将导致光辐射衰减区域的出现,衰减区域的尺寸和光辐射衰减的程度均随着焊接速度的增加而减小,且相对于匙孔的前沿,其位置向熔池的后方移动。通过分析匙孔区域的光辐射衰减程度和匙孔前壁角度的变化,将光辐射分布的特征与焊缝的尺寸结合起来,建立了两者之间的对应关系,从而实现了焊缝尺寸的检测。

Base on a CMOS coaxial visual sensing system,the optical radiation feature of the keyhole and weld pool in Nd∶YAG laser full penetration welding was analyzed,and the detection of the weld dimension was realized.The results show that,when the welding was proceeding in keyhole opening mode,a low brightness field can be observed inside the high brightness of laser irradiation area.With the increasing of the welding speed,the dimension and the attenuation degree of the low brightness field are decreased,and moved to the hind weld pool.By the analyzing of the variation of the attenuation degree and the keyhole front wall angle,the relationship between the optical radiation feature and the weld dimension was established,and the detection of the weld dimension was realized.