针对现有线结构光传感系统标定过程中对设备要求高、标定过程繁琐等问题,提出一种基于三点透视模型的快速标定方法。引入一个可自由移动的平面靶标,靶标上只需要共线且相互位置确定的3个特征点,利用共线三点建立三点透视数学模型,根据3个特征点以及光条纹在摄像机像面的成像信息,获取了光平面上标定点在摄像机坐标系下的坐标。平面靶标在视觉范围内任意移动几个位置,得到光平面上多个标定点坐标,从而确定光平面方程。实验证明,该方法平均相对测量误差约为0.72%,标定时不需要昂贵的辅助调整设备,也不需要求解坐标系之间的转换矩阵,简单、快速,适合现场标定。
In order to solve the calibration problems in line structured light sensor systems such as requirements for high accuracy calibration models, complicate calibration procedures and so on, a calibration method based on perspective-three-points was proposed. A calibration model was established by introducing a planar target that could move freely with three collinear and known mutual location points. The calibration point coordinates in a camera coordinate system could be calculated by using the imaging information of three points and the light stripes on image plane of the camera. The spatial pose between the camera and the light plane could be calibrated by moving the reference plane at several arbitrary places in the sensor range. Experiments show that relative accuracy of the sensor is about 0.72%. The method is suitable for the field calibration,for it has advantages in its simple and flexible calibration, the cost of calibration equipment, and not to calculate the transformation matrix among different coordinate systems.