Automatic Inspection System for Automotive LiDAR Alignment Using a Cubic Target

This study aimed to develop an automatic and accurate inspection system for LiDAR alignment for application in the automobile industry. The proposed inspection system is a one-shot and static method that uses only a single cubic-shaped target at a close range of less than 2 m. The LiDAR pose from the target frame, and consequently from the vehicle body, is estimated by using the 3D positions of the vertices of the cubic target. Instead of directly extracting the vertices from the point cloud data, the points are estimated accurately through a series of processes that find the best-fit orthogonal planes and their intersections. The proposed method can be efficiently applied to low-resolution LiDAR and provides higher accuracy and precision than a similar static inspection method that uses a planar target (Oh et al., 2021). Experimental evaluation of the proposed method with a low-resolution LiDAR (Velodyne VLP-16) resulted in measurement errors of less than 0.04 degrees and 1 mm for rotation and translation alignment, respectively. Therefore, the designed inspection system is practical for in-factory applications because of its one-shot static methodology that uses only a simple cubic target and detection of the alignment error with high accuracy.