Evaluation of Mobile Platforms for Automation of Metro Tunnel Inspections

Abstract: Metro tunnel inspections face growing demands from urbanization and tight maintenance windows, yet manual and time-consuming inspection methods remain. While rail-bound vehicles, wheeled and tracked robots,´quadruped robots, and Unmanned Aerial Vehicles (UAVs) show promise for inspection tasks, no systematic evaluation addresses metro-tunnel specific constraints like track geometries, tunnel access and inspection windows for mobile platform choice. This paper reviews inspection platforms, derives evaluation criteria from literature, operator interviews, and observations, and quantitatively compares platforms across sensing, payload, speed, runtime, deployment, and locomotion. Results identify optimal use-cases for each system, guiding deployment strategies for automated metro-tunnel inspections.