Underground Localization Performance Test Report (GNSS/LiDAR/UWB)

Underground localization presents unique challenges due to the absence of reliable GNSS signals, dynamic environmental conditions (e.g., shifting debris, poor lighting, metallic reflections), and constrained infrastructure limiting anchor deployment. The test report systematically evaluates how tightly integrated sensor modalities—primarily LiDAR for geometric mapping and odometry, UWB for centimeter-accurate short-range ranging to fixed anchors, and opportunistic GNSS (at portal ingress/egress)—compensate for each other’s weaknesses. Core testing involves deploying high-fidelity ground-truth systems (e.g., robotic total stations, survey-grade RTK-GNSS at accessible zones, or pre-mapped inertial reference trajectories) alongside the candidate localization stack across representative underground routes (ramps, stopes, intersections) under varying operational loads and environmental stressors. Performance is analyzed statistically over time—reporting mean/median 3D position error, CEP (Circular Error Probable), trajectory divergence, and failure modes (e.g., UWB anchor loss-induced drift, LiDAR feature starvation in smooth-walled tunnels). Crucially, the report links localization fidelity to downstream AHS safety-critical functions: path tracking error budgets, collision avoidance margins, and docking precision for autonomous loading/unloading—thereby informing system certification, redundancy design, and maintenance intervals.