Perception Limitation of LiDAR Sensor in Autonomous Vehicles Under Rainfall Condition

Abstract:

A study was made of the performance limitations of LiDAR under rainfall conditions. Based on the artificial rainfall facility in a proving ground， we collected point cloud data from a mechanical rotating LiDAR and a hybrid solid-state LiDAR separately. By constructing a metrics set including five objective indicators， the degree of influences of rainfall conditions on two kinds of LiDAR were compared and analyzed. The test results show that the point cloud number decreases， the reflectivity is weakened， but the information entropy of reflectivity increases.The signal-to-noise ratio reduces. The fogging phenomenon of rainfall significantly deteriorates the performance of the LiDAR. Within 20~40m， a 91.49% reduction of the average point cloud number and a 96.77% reduction of the average reflectivity of the mechanical rotating LiDAR are found. In comparison， the hybrid solid-state LiDAR with a longer wavelength and non-repetitive scanning has better penetrability under rainfall， resulting in a relatively stable number of point clouds. However， the point cloud of the hybrid solid-state LiDAR will contain more raindrop echoes with lower reflectivity， so a more effective noise filtering algorithm is necessary for application.