As of October 1, 2016, the SWUTC concluded its 28 years of operation and is no longer an active center of the Texas A&M Transportation Institute. The archived SWUTC website remains available here.

167141-1 Report Abstract

Developing a Diagnostic System for Air Brakes Used in Commercial Vehicles

Shankar C. Subramanian, Swaroop Darbha and K. R. Rajagopal, Texas A&M University, March 2006, 92 pp. (167141-1)

The safe operation of vehicles on roads depends amongst other things, on a properly functioning brake system. Air brake systems are widely used in commercial vehicles such as trucks, tractor-trailers and buses. In these brake systems, compressed air is used as the energy transmitting medium to actuate the foundation brakes mounted on the axles. In this report, a model-based diagnostic system for air brakes is presented. This diagnostic system is based on a nonlinear model for predicting the pressure transients in the brake chamber that correlates the brake chamber pressure to the treadle valve (brake application valve) plunger displacement and the pressure of the air supplied to the brake system. Leaks and “out-of-adjustment” of push rods are two prominent defects that affect the performance of the air brake system. Diagnostic schemes that will monitor the brake system for these two defects are presented. These schemes are corroborated with experimental data obtained from the brake testing facility constructed at Texas A&M University.

Keywords: Modeling, Air Brake Systems, Commercial Vehicles, Diagnostic System

ENTIRE REPORT (Adobe Acrobat File – 3.3 MB)