Fig. 1. Diagram of system structure

Fig. 2. Calibration of grid-structured light

Fig. 3. Point-to-plane ICP

Fig. 4. Setup of measuring device

Fig. 5. Calibration images of grid-structured light

Fig. 6. Corner points of structured lights in camera coordinate system

Fig. 7. Fitted grid-structured lights

Fig. 8. Images and results of 3D point cloud measurement. (a) Original image; (b) processed image; (c) image of 3D point cloud

Fig. 9. Measurement point cloud and reference point cloud before and after coarse registration. (a) Before coarse registration;(b) after coarse registration

Fig. 10. Results of point cloud fine registration. (a) ICP registration; (b) point-to-plane ICP registration; (c) improved ICP registration

Fig. 11. Comparison of registration error and time. (a) Registration error; (b) registration time

Fig. 12. Comparison of measurement results of rotation matrix of different algorithms

Fig. 13. Measurement errors of rotation matrix and translation matrix. (a) Measurement error of rotation matrix; (b) measurement error of translation matrix