Technology Digests / Laser Broken Rim Detector (BRD) – Part II

TD22-019

August 1, 2022
Authors
  • Silvia Galvan-Nunez
  • Anish Poudel
  • Brian Lindeman
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Key Findings

  • MxV Rail has successfully tested a second prototype laser broken rim detector (BRD) system. Statistical approaches were used to estimate the probability of hits (POH) and probability of detection (POD), both of which demonstrated the capability of the BRD system.
  • There was no clear distinction of the effect of speed in the POH and POD values.
  • Although the mean POD typically increased as the flaw length increased, there were several exceptions at speeds greater than 40 mph.
  • Similar to other systems tested, false positive readings ranged between 0 and 20 percent with an average FPR of 9 percent for all test runs. Further development is needed to reach an acceptable balance between false positive rate and POD (or POH) rates.

Laser Broken Rim Detector (BRD) – Part II

MxV Rail (formerly TTCI) collaborated with Canadian National Railway (CN) and commercial vendors to evaluate next generation optical broken wheel detectors capable of inspecting the broken wheels in the train at speeds up to 70 mph. A previous Technology Digest 1 reported the testing and results obtained from one such prototype system. The work reported here focuses on a second similar prototype system, known as the laser broken rim detector (BRD) system. The prototype system tested demonstrated a good capability of detecting broken wheels but suffered from high false positive rate. Further development and testing is recommended to reach an acceptable balance between false positive rate  and POD/POH rates. The overall objective of this research and testing included demonstrating and evaluating the capability of such systems to detect broken rims at track speeds over a wide range of testing conditions. All testing was conducted at the Transportation Technology Center, Pueblo,…