针对大尺寸物体形貌视觉测量中三维数据拼接问题提出了一种基于平面圆靶标的三维数据拼接方法。该方法将平面圆靶标放置在被测物前，三维测头分别在相邻两个测量位置拍摄平面圆靶标，然后以平面圆靶标为中介，利用圆特征边缘点集对应，实现前后两个测量位置的三维数据拼接。经实物实验验证，在x、y、z轴方向的拼接精度分别为0.067、0.035、0.134 mm，与相同实验条件下方格靶标法的精度相当。在被测物存在部分遮挡的情况下，方格靶标法因为角点误匹配而导致三维数据拼接失败，而本文方法可实现数据拼接在x、y、z轴方向的拼接精度分别为0.062、0.037、0.168 mm。

A three-dimensional (3D) data registration method based on planar circular target is proposed to solve the problem of 3D data registration in the vision measurement of large-scale object surface profile. With the planar circular target placed in front of the measured object, 3D vision system takes photographs of planar circular target at adjacent measurement positions. Then the planar circular target is used as an intermediary, and registration of 3D measurement data from adjacent measurement positions is achieved by establishing correspondence between edge points in circle. As shown in experiments, the data registration root mean square (RMS) error of x, y and z, with considerable accuracy of the planar grid target method, is 0.06, 0.03 and 0.134 mm respectively. When the measured object is partly occluded, the data registration RMS error of x, y and z is 0.06, 0.03 and 0.168 mm respectively. While the method of planar grid target fails to registration because of mismatch of 3D grid data.