一种大尺寸视觉测量系统标定方法

Aiming at the calibration problem of distance between base coordinate system and the vision sensor coordinate system, a high-precision calibration method was proposed. Firstly, an intermediate coordinate system was established with a laser tracker. And then, the least squares point set registration error was used to calibrate the relationship between the coordinate system of the laser tracker and the coordinate system of the vision sensor. The least square average rigid body transformation matrix was used to calibrate the relationship between the laser tracker coordinate system and the base coordinate system. Finally, the coordinate relationship between the measurement base coordinate system and the vision sensor coordinate system was established by coordinate transformation to carry out the measurement of spatial phase angle accurately for large size workpieces. Simulation results show the effectiveness of the least squares point set registration method in solving coordinate system relations, and validate the registration error of least squares point set registration method is related to the size of registration point set, sensor accuracy and sensor pose relationship. Test results show that the calibration method can accurately and reliably measure the spatial angle of large-sized workpieces, and the measurement standard deviation can reach up to 0.007 5°, fully meeting the process requirement.