大功率盘形激光焊匙孔特征提取

Feature extraction of keyhole during high-power disk laser welding

在大功率盘形激光焊接过程中,匙孔形态与焊接质量之间有直接的关系。研究匙孔形态特征表征方法,对实时分析激光焊接质量具有重要意义。以10 kW大功率盘形激光焊接304不锈钢为试验对象,应用近红外高速摄像机摄取熔池动态热像,通过图像处理分割出匙孔。研究匙孔图像轮廓的链码特征,并且用链码统计概率描述匙孔轮廓特征,同时定义和提取包括匙孔面积、周长、质心、最前端点坐标、形状因子等匙孔特征。试验结果表明,所提出的方法能有效描述和分析匙孔的形态。

In the, process of high-power disk laser welding,the keyhole feature has an important relationship with welding quality. Researching on keyhole fealure has vital significance on real-time analysis of welding quality. A new approach to extract the keyhole feature was investigated during high-power disk laser bead-on-plate welding of Type 304 austenitic stainless steel plates at a continuous wave laser power of 10 kW. An infrared and visible sensitive high-speed video camera was used to capture the dynamic images of the laser welding keyhole. The keyhole was segmented by using the image processing. The chain eode of a keyhole outline was statistically analyzed. Also, the area,perimeter,centroid, coordinates of front and shape factor of a keyhole regional characteristics were defined and calculated as the characteristic parameters of a keyhole. Experimental results showed that the keyhole shape could be effectively described by using the proposed method.