针对结构光自扫描测量系统参数标定问题,提出了一种基于共面法的高精度标定方法,能够同时标定系统的内外参数。建立了相机和系统模型,采用张正友方法标定相机和平面棋盘靶标内外参数,针对系统标定需求完成了靶标位置规划,在同一光平面下变换靶标位姿获取共面光条中心点,利用多组中心点数据分别求解各光平面方程。由于多个平面交线不唯一,定义了优化目标函数对振镜转轴在相机坐标系下的表达进行优化求解,求得振镜坐标系与相机坐标系的转换矩阵完成标定。该方法标定过程简单,算法运算量小,便于现场标定。结果表明,标定方法具有较高精度,能够满足测量要求。
For the issue of structure- light auto- scanning measurement system parameters calibration, a high precision calibration method based on coplanarity is proposed, and the internal and external parameters of the system are calibrated simultaneously. The camera model and the system model are established. The intrinsic and extrinsic parameters of camera and the planar chessboard target are calibrated with the Zhang method. In view of the system calibration requirements, the target location planning is completed, and the position and orientation of the target is changed in the same light plane to obtain coplanar light stripe center points. The light plane equations are solved separately in several light stripe center point data groups. Considering that cross lines of several light planes are more than one, an optimized objective function is defined to solve and optimize the galvanometer shaft expression in the camera coordinate system. The transformation matrix from galvanometer coordinate system to camera coordinate system is obtained. The calibration process is simple, and computation of the algorithm is small. It′s suitable for calibration on spot. Results show that the high precision calibration method is able to meet the requirement.