结构光焊缝视觉检测系统中投影仪标定法

Projector calibration method for structured light seam vision inspection system

在基于结构光的焊缝视觉检测应用中,标定是实现高精度检测的关键。提出了一种基于平面投影的结构光视觉系统快速标定方法。该方法将投影仪当作一个逆向的摄像机,使用一块带有四角棋盘格作为靶标的平面标定板对投影仪进行标定。利用摄像机提取特征点在投影仪图像空间中的对应点,建立投影仪图像和靶标图像的对应关系,从而将投影仪标定转化为成熟的摄像机标定。得到标定结果后,即可以求得特征点的三维坐标。最后结合标定结果对试验焊缝板进行了三维重构。结果表明,所提出的标定方法操作过程简便、精度高,可适用于焊缝三维信息检测等场合。

In the seam surface visual inspection of structured light,calilu＇ation is the key to the accurate inspection. A projector calibration method based on projecting planar is proposed. In this method,the projector can he viewed as an inverse camera,and planar calibration object with four printed checkerboard is used to calibrate the projector.With the camera,the features of the target and the prnjeeted image are extracted,establish accurate projector image and camera image correspondence.Thereby, the projector can be calibrated using a well established camera calibration algorithm.By the result of calibration, the coordinates of characteristic spot can be obtained. In final, test wehts were measured by this structure light system and reconstructed.The method is simple, convenient,and accurate. So it can be applied to the weld 3D inspection area.