Accurate Alignment Inspection System for Low-Resolution Automotive LiDAR

A misalignment of LiDAR as low as a few degrees could cause a significant error in obstacle detection and mapping that could cause safety and quality issues. In this paper, an accurate inspection system is proposed for estimating an automotive LiDAR alignment error after sensor attachment on a vehicle. The proposed method uses only a single target board at a close range to estimate the orientations and the horizontal position of the LiDAR attachment with sub-degree and millimeter level accuracy. It is a static method for the stationary target board and vehicle during the inspection. Also, it only requires one pose of the target board and does not utilize other sensors, such as a camera or GPS. The performance of the proposed method is evaluated using a test bench that can control the reference yaw and horizontal translation of LiDAR within ranges of 3 degrees and 30 millimeters, respectively. The experimental results for a low-resolution 16 channel LiDAR (Velodyne VLP-16) confirmed that misalignment could be estimated with accuracy within 0.2 degrees and 4 mm. The high accuracy and simplicity of the proposed system make it practical for large-scale industrial applications such as automobile manufacturing process that inspects the sensor attachment for the safety quality control.