LiDAR scene projector (LSP) for the performance testing of autonomous multi-line scanning LiDAR

Multi-line scanning LiDAR with large field of view (FOV) is one of the core sensors in an autonomous vehicle. However, the lack of efficient testing methods is becoming a major bottleneck for its mass production. In this paper, we introduce a test instrument named LiDAR scene projector (LSP) for testing multi-line scanning LiDARs on a production line. The LSP is designed based on an optical architecture that employs multiple 4F optical relay systems. Through these 4F systems, light is transmitted between different optical pupils with controllable intensity, time delays, and propagation directions. A “predictive scanning” mechanism is applied in the LSP. By monitoring the scanning speed of the laser beam transmitted by the LiDAR in the current frame, the scanning law of the next frame is predicted, thereby ensuring that the laser echo beam projected by the LSP remains always parallel and opposite to the laser beam transmitted by the LiDAR under test, thereby achieving tracking scanning between the two. The LSP achieves the following main parameters: the distance simulation range is 10 ∼ 150 m, the distance resolution is 15 mm, the FOV is 15° (horizontal) × 25.4° (vertical), the angular resolution is 0.02° both in horizontal and vertical, the modulation transfer function (MTF) at 50 lp/mm is 0.44, the maximum geometric distortion is 1.50%, and the maximum simulation fidelity is 0.072. The LSP demonstrates the ability to shorten test time and improve test efficiency in LiDAR production testing, showing great application potential.