自寻边激光切割机相机的安装角度是影响机器视觉系统获取图像质量的最重要因素, 它直接决定系统提取切割路径的精度。提出了一种利用激光切割系统本身的设备来检测相机安装的垂直度。首先, 在切割床的固定位置铺设的标定纸上打出由激光斑点组成的标准圆图像, 并由机器视觉系统提取该圆的轨迹和圆心坐标; 然后, 通过齐次坐标变换, 建立工作平面到CCD成像平面的坐标变换关系, 并利用预先建立的计算模型, 就可计算出CCD光轴与工作平面的夹角。实验结果显示了所提出的方法对激光切割系统CCD安装角度的检测是一种可行的解决方案。

The installation angle of CCD of intellingent laser cutting machine is the most important factor affecting the image quality captured by machine vision system. It directly affects the accuracy of the cutting path. In this paper, an innovative method is proposed to use the equipment of own system of laser cutting machine to detect installation verticality of CCD. First of all, a standard circle graph composed of laser spots are carved on calibration paper in a fixed position of cutting bed, the circle path and center coordinates are got by machine vision system. Then the coordinate transformation from working plane to CCD plane is built through homogeneous coordinate transformation. Finally the angle between the CCD optical axis and the work plane can be computed out by computational model set up in advance. Experimental results show that the method presented in this paper is a feasible solution for measuring the installation angle of CCD in laser cutting system.