The calibration method of the external rotation axis for multi-line LIDAR

The vertical field of view of the multi-line LIDAR is usually only about 30 degrees. To increase the vertical field of view, the standard method is to add an external rotation axis to form a rotating LIDAR device. Here need to calibrate accurately the position and attitude relationship between the multi-line LIDAR and the rotation axis. In order to calibrate the external rotation axis of a multi-line LIDAR, we proposed a method in this paper. First, rotate the LIDAR clockwise about the rotation axis to record the calibration board point cloud data at different rotation angles, and the corresponding rotation angles. Then, rotate these calibration board point cloud data counterclockwise around the rotation axis. If there is no error in the rotation axis, these point cloud data of the calibration board point will coincide. Based on this principle, by minimizing the thickness of the calibration board point cloud data, the rotation axis is iteratively optimized to obtain the optimal result. The performance of this algorithm is verified on a series of real data and synthetic data. Compared with similar methods, the estimated parameters of the proposed method show that the TPC (point cloud thickness) error is reduced by 5.4%.