Localization Methods for Tube Exploration

Aiming at the localization of lunar lava tubes, the volcanic lava cave in Haikou City, Hainan Province, was selected as the experimental area for simulated lunar lava. Localization methods including stereo vision-based method, laser scanning point cloud based method, vision fused IMU based method, laser point cloud fused IMU based method, and vision, laser point cloud and IMU fused method are applied to localization in the field areas of simulated lava tubes. The experimental results show that the accuracy of stereo vision could reach 3.59% in long-distance travelling mode, but the accuracy and robustness decreased significantly in harsh lighting conditions. Lidar could achieve a similar-level accuracy as vision-based method, reaching 1.89% in local area, but its robustness was affected by data acquisition rate and field of view. The integrated localization method using stereo vision, LiDAR, and IMU achieved robust localization results in lava tube areas with extremely harsh lighting and terrain undulations, making it the preferred choice for long-distance continuous localization. The research conclusions provide valuable reference for subsequent research on sensor configuration and localization methods for lunar lava exploration missions.