Design and Operational Assessment of a Mobile Robot for Undercarriage Inspection of Railcars

This research assesses the design and track operation of a track crawler robot (TCR) for practical and easy inspection of stationary railcars' undercarriages in an effort to detect any pending failures or assess any security risk of out-of-sight objects. The research leverages against a robot available at the Railway Technologies Laboratory (RTL) of Virginia Tech and offers improvements to the structure, drive system, imaging devices, and operator remote control to improve the speed, track maneuverability, and duty cycle of the robot. The TCR includes a drive system consisting of two AC motors that operate a track (like tank tracks). It further includes two GoPro® cameras, light system, and onboard power for approximately one hour of maximum power operation. The details of the TCR design are introduced through its operational requirements, which guided its initial design. The specific design configurations are used to derive the applicable parameters essential for track operation of the robot. The TCR's subsystems are evaluated individually to assess their strengths and weaknesses, which are then used to guide the specific tasks in improving the overall system's performance. The details of the required modifications are included for the imaging, lighting, control, frame structure, and mobility subsystems.
For each subsystem, test results are used to engineer workable solutions for overcoming the shortcomings or implementing additional functionality. The redesigned system is further evaluated through testing to assess the improvements due to modifications. Beyond laboratory tests, a final assessment of the system was done on a branch line and mainline track, both with great success.
The recorded images and operational evaluation of the TCR prove it to be a valuable inspection tool for the railroads to inspect out-of-sight undercarriage components of stationary trains in a railyard or siding, to identify any failed or nearly-failed equipment before they develop into a major or out-of-compliance issue. The TCR also promises to be useful for security agencies to easily and efficiently inspect trains entering secured areas to uncover any suspicious devices.