Fig. 1. Relative position of lidar coordinate system and vehicle coordinate system

Fig. 2. Uncalibrated lidar coordinate system

Fig. 3. The second step calibration algorithm principle. (a) Clustering center of calibration rod; (b) multi-frame same calibration rod clustering center with reference to the lidar coordinate system

Fig. 4. Calibration error

Fig. 5. Ground levelness function f value

Fig. 6. Extraction of ground point cloud

Fig. 7. Results of the first step calibration

Fig. 8. Scene of the second step calibration

Fig. 9. Calibration pole extraction and clustering

Fig. 10. Results of the second step calibration