Evaluation of Transit Vehicle Brake Inspection through Ultrasonic Emissions Analysis

Advanced warning of brake problems can lead to benefits in increased transit safety and operating efficiencies. Transit safety will be improved through fewer accidents and injuries due to brake failures.

The TRB IDEA (Innovations Deserving Exploratory Analysis) Program's Transit IDEA Final Report 94: Evaluation of Transit Vehicle Brake Inspection through Ultrasonic Emissions Analysis details a new approach for improving transit safety by analyzing ultrasonic sounds emitted by braking. Vehicle brakes emit ultrasonic energy (acoustic frequencies above what humans can hear) as part of the friction process; the spectra of these sounds are highly dependent on the mechanical condition of the brake and can be used to detect problems.

The sensors can be automated to provide daily analysis of brakes for every vehicle and issues alerts if problems are detected. The data can be used to optimize maintenance schedules based on the conditions of the brakes.