On the Application of LIDAR Sensors for Track Geometry Monitoring

Abstract

The applicability of Doppler based, Light Detection and Ranging (LIDAR) sensors for track geometry monitoring is investigated in this article. The optimum configuration of the LIDAR lenses, suitable for effective lateral track geometry measurements, is presented. In the proposed embodiment, two low-elevation LIDAR optics are employed with their beams reflected off of the rail gage face on each side to capture speed signals from both rails individually. A processing technique is developed based on the frequency bandwidth dissimilarities between the vehicle speed and track geometry irregularity to separate the two from each other. LIDAR system is body-mounted to a geometry inspection car and tests are carried out on revenue service track. The results indicate that LIDAR optics can provide a reliable track monitoring instrument for use over substantial track mileage in inclement weather and harsh track conditions with minimal operator supervision.