设计了一种以两轴数控转台为载体的双目立体视觉测量系统。讨论了系统多视角测量数据的拼合原理和实现方法,提出了一种对数控转台两个旋转轴准确标定的方法。该方法首先在转台上粘贴3个以上的圆形标记点并让转台的待标定轴正向旋转,从多个位置测量圆形标记点,获取标记点中心的三维坐标。根据任意两个位置获取的标记点中心坐标点集就能计算出待标定轴的位置,利用多个位置的冗余约束优化确定轴线在世界坐标系下的最终位置从而进一步提高标定精度。在对转台的两个转轴做出精确标定的基础上,实现对转台上放置的被测物体的多视角自动拼合测量。该系统能快速、有效地完成产品表面点云测量,解决了在产品上粘贴标记点实现多视角点云数据拼合时导致的表面数据丢失及多次测量之间数据重叠率不易控制等问题。
A measurement system of binocular stereo vision that uses the two-axis NC turntable is designed. The multi-view measurement data registration principle and implementation are discussed, and the method for accurate calibration of the two rotational axes of the NC turntable is than three circular markers are pasted on the turntable; 2) proposed. The core of this method consists of: 1 ) more the turntable's axis to be calibrated is made to rotate in a positive direction; 3) the circular markers are measured from several positions, thus obtaining the 3D coordinates of the center of the circular markers; 4) the position of the axis to be calibrated can be calculated from any two of the coordinate point sets of the center of the circular markers; 5 ) with the redundant constraints of the several posi- tions, the final position of the axis in the world coordinate system is determined, thus further improving the calibra- tion accuracy. The multi-view automatic registration of the object to be measured is implemented though accurately calibrating the two axes of the turntable. Experiments are performed to assess the calibration accuracy with our method; the experimental results show that, the measurement system designed with our method can measure the point cloud on the surface of a product quickly and effectively, and can solve the problem of data loss and the diffi- culty in controlling the data overlap caused by multiple measurements.