Smart Infrared Brake Inspection Systems identify trucks with faulty systems. Of the vehicles flagged as having thermal issues, 86 percent were found to have a violation and 83 percent of those vehicles were placed out-of-service.

A field operational test for commercial motor vehicle inspection enforcement.

Date Posted

Smart Infrared Inspection System Field Operational Test

Summary Information

The Smart InfraRed Inspection System (SIRIS) is designed to assist inspectors in identifying vehicles with defective wheel components. As a commercial motor vehicle (CMV) approaches a weigh station, infrared cameras mounted at the roadside measure the temperatures of brakes, tires, and wheel bearings. The thermal images collected are automatically processed by SIRIS and presented to enforcement personnel within the inspection station. Vehicles displaying potential defects are automatically flagged and enforcement staff are notified.

The main goal of the field operational test was to evaluate the performance of the SIRIS prototype and determine if the system was viable for CMV enforcement. From March 2010 to September 2010, the Oak Ridge National Laboratory facilitated the field test at the Greene County Inspection Station (IS) located on I-81 in Greeneville, Tennessee.

During the testing period, all CMVs traveling on I-81 South were diverted onto a high-speed bypass lane. Sample sets of four consecutive CMVs were directed onto another lane that headed towards the pit-scale. These trucks were required to brake, reduce speed, and pass by the SIRIS camera. One vehicle in each sample set was then to receive a full Level-1 inspection and have their brakes evaluated using a Performance-Based Brake Tester (PBBT) machine. Enforcement personnel conducting the inspections were not allowed to view the SIRIS data before each inspection. CMVs found to have defects were subject to normal enforcement protocols.

Overall, 413 vehicles were randomly selected from the mainline and 384 of them were successfully scanned by the SIRIS. To evaluate performance, the SIRIS data were compared to the inspection data.

  • Thirty-six (36) of the 384 vehicles scanned by SIRIS displayed a potential brake or tire violation.
  • All 36 of the vehicles flagged were subjected to a Level-1 inspection which resulted in 30 (83.3 percent) of these vehicles being placed out-of-service for a related violation, and 31 (86.11 percent) identified as having a flaw of some type relative to brakes, tires, or wheel bearings.
Although the majority of brake violations were due to insufficient brake linings and brakes being out of adjustment, a SIRIS brake flag does not necessarily mean a brake violation. Since the SIRIS uses temperature data to determine if a wheel needs to be inspected, a brake flag could be a sign of another problem that is preventing the brake from performing optimally (e.g., flat tire shifted weight causing brake to exert more force to stop).
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