针对现有线激光单目视觉传感器参数标定方法中靶标移动需要精密机械控制或可自由移动靶标摆放位姿受约束等不足, 提出一种靶标可自由移动且摆放位姿无约束的新标定方法。根据靶标特征点的成像点所构成向量簇的叉积方向集合的射影不变性, 对成像点排序, 建立靶标特征点与其成像点的对应关系; 由光刀中心拟合直线与靶标特征点的成像点所构成包络求交, 提取光平面特征点, 并根据交比不变原理计算其三维坐标; 最优化拟合计算单目摄像机内外参数及线激光投射器光平面参数, 实现传感器参数的精确标定。试验表明, 该标定方法操作自由、步骤简便, 具有较理想的标定精度。

A new calibration method of line laser monocular vision sensor based on a new free position and orientation planar target is proposed for the deficiencies in existing methods. Projective invariance of a set of vector product orientations are applied to sort the image control points and then calculate the correspondence between image control points and target control points. Laser control points in each image are extracted by calculating the intersection points of laser stripe and ordered straight lines connecting control points. 3D coordinates of the laser points in camera coordinate frame are calculated by cross ratio invariance principle. Therefore the sensor is precisely calibrated with the optimization calculation of camera parameters and laser plane parameters. Verified by experiments, this calibration method has high-freedom operation, simple calibration process and ideal calibration accuracy.