基于自由靶标的线结构光视觉测量系统标定研究

Calibration of line structured-light vision measurement system based on free-target

针对现有的线结构光视觉测量系统现场标定方法存在效率低、操作复杂等不足,提出了一种基于自由移动平面靶标的标定方法。该方法以平面靶标作为标定对象,首先采用张正友的方法标定出了摄像机内部参数,然后引入了线结构光和自由移动平面靶标,以各种位姿下靶标内的激光条纹与棋盘格角点边线交点作为特征点,求取了特征点在摄像机坐标系下的坐标,并拟合出了结构光面平面方程,从而完成了整个测量系统的标定。试验结果表明,采用上述方法标定后的线结构光视觉测量系统测量误差小于1%,达到了较高的标定精度,能够满足使用要求。

Aiming at the problem of existing line structured light vision measurement system calibration method such as low efficiency,complex operation,a approach of calibration based on free plane targets was proposed. This method took planar target as a calibration object.First,according to the two-dimensional plane calibration theory of Zhang,the internal and external parameters of the camera was calculated.Then the line structured-light and free planar target were introduced,with taking intersection-points of laser stripe and checkerboard border in a variety of target positions as feature points,the coordinates of the feature points in the camera coordinate system were calculated,and structure-light equation of plane to complete the whole measurement system calibration was fitted. The results indicate that the line structured light vision measurement system measurement error is less than 1% by the above methods of calibration,and reaches the high calibration precision.