This study proposes a bumper-mounted LiDAR sensor system (BMLSS) to achieve 3D environmental perception and precise localization for autonomous vehicles operating under low-height sensing conditions. Conventional roof-mounted LiDAR configurations can ...
This study proposes a bumper-mounted LiDAR sensor system (BMLSS) to achieve 3D environmental perception and precise localization for autonomous vehicles operating under low-height sensing conditions. Conventional roof-mounted LiDAR configurations can suffer from near-range observation gaps, and their installation is often constrained by vehicle structures, design requirements, and aerodynamic considerations. To address these issues, the proposed system leverages geometric information from low-height, limited-FOV point clouds acquired at the vehicle bumper, aiming to realize SLAM and robust real-time localization on a real vehicle platform. The proposed framework combines SLAM-based local estimation with map-matching-based global correction to validate the applicability of the bumper-mounted configuration. To improve data quality and mitigate ground-induced interference, it performs inter-sensor spatial calibration and time synchronization, and applies preprocessing steps including ROI filtering, statistical outlier removal (SOR), and radius outlier removal (ROR), together with a preprocessing-driven targetless calibration procedure. In addition, an SLAM algorithm tailored to the bumper LiDAR setup is introduced, and an IMU–EKF-based sensor fusion module is implemented to enhance robustness beyond LiDAR-only estimation, resulting in a real-time localization system based on a 3D point-cloud map. Experimental results on a real autonomous vehicle platform show that the proposed system maintains map alignment errors within 0.05 m in the SLAM stage and achieves stable mapping and real-time localization in complex urban and curved-road environments. Moreover, map-based real-time localization achieves positioning accuracy within 1 m, demonstrating the feasibility of a cost-effective bumper-mounted LiDAR perception and localization architecture for low-speed urban driving, automated parking, and operation in narrow spaces.