钨极氩弧焊熔池表面高度测量中变形条纹图的获取

Acquisition of deformed stripe images in height measurement of gas tungsten arc weld pool

提出一种基于条纹反射和傅立叶变换的测量GTAW熔池表面高度的新方法.利用激光器将光栅条纹投影在GTAW熔池表面,反射光轴上设置双透镜系统以转移熔池物面,利用空间滤波的方法阻挡弧光成分,在输出面放置白屏接收反射的熔池变形激光条纹,用CCD对屏上变形条纹实时成像.分析了焊枪位置、熔池的反射性能、弧光辐射等对变形条纹图获取的影响,找出合适的投影角度、拍摄系统参数以达到最好的拍摄效果.结果表明,所获得的熔池区变形激光条纹图像清晰且满足图像处理要求,并初步计算出熔池前部的表面形貌.

A new method which was based on stripes reflection and fourier transform to measure the three-dimensional surface shape of the GTAW weld pool was proposed in this paper.The grating stripes was projected onto the weld pool surface using the laser.A double-lens system was set on the reflecting optical axis to transfer the weld pool surface and the arc was eliminated by spatial filter.Deformed stripes caused by the weld pool surface shape were reflected and interspected by an imaging panel placed on the output plane of the double-lens system.A CCD camera was used to observe the changes of the reflected deformed laser stripes on the imaging panel an real time.The effects of the torch position,reflection properties,arc radiation and other factors were analyzed to get the appropriate projection angle and system parameters.The result showed that the deformed stripe images obtained from the weld pool surface were clear and met the requirements of image processing.Finally,the surface shape of foreside weld pool was measured preliminarily.