Ruhl Forensic Leader in Forensic Technology

Publications

Technical Papers


SAE 1999-01-3782
A Prototype Computer Based Test System to Test Commercial Vehicle Air Brake Systems: Application and Test Results

Craig V. Robertson
Ruhl and Associates - Forensic, Inc.
Roland L. Ruhl
University of Illinois at Urbana-Champaign
Philip J. Smith
Ruhl and Associates - Forensic, Inc.

This paper describes a practical and efficient approach for determining complete transient, as well as steady state response of tractor-trailer air brake systems by recording pushrod displacement and air brake service line pressure as a function to time. The test hardware utilizes easy to fabricate "clip on" transducers to measure pushrod stroke length. Data acquisition is via LABVIEW(. All transducers are easy to temporarily affix to any tractor-trailer and require no alteration to the vehicle. A complete system check takes less time than manually measuring pushrod stroke as required under FMCSA. This system with one treadle application and release gives digital timing and displacement history of all brakes. Useful information includes: application and release profiles (pushrod velocity), shoe compliance upon seating and crack pressure release points for both tractor and trailer relay valves. The authors believe this testing protocol will be useful to Fleet Managers and Maintenance Personnel, Law Enforcement specializing in Commercial Vehicle Inspection and Accident Investigators who need information on brake system performance.

Copyright 1999 Society of Automotive Engineers, Inc.

Society of Automotive Engineers
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Technical Papers

SAE 2013-01-0785
The Accuracy of Pedestrians in Estimating the Speed of a Moving Vehicle

SAE 2010-01-0046
Observed Errors in Distance Estimation

SAE 2007-01-0758
The Experimental Study of the Air Flow Produced by Road Vehicles and its Potential Destabilizing Effect on Nearby Pedestrians

SAE 2006-01-3557
Usable Models for Free and Forced Cooling of Commercial Vehicle Drum Brakes

SAE 2006-01-3556
Comparison of Established Heavy Brake Heating / Cooling Models with HVE Brake Designer in a Real Mountain Accident

RF2005-01
Commercial Vehicle Onboard Electronics - Global Positioning Systems, Engine Control Modules and Safety Systems and Devices

IMECE2004-59566
Analysis of a Common Cause Hypothesis in a Forensic Product Defect Analysis

SAE 2004-01-2717
Safety Concerns in Automatic Control of Heavy-Duty Articulated Vehicles

SAE 2003-01-3393
Numerical Methods for Evaluating ECM Data in Accident Reconstruction and Vehicle Dynamics

SAE 2003-01-3363
Development of a Dynamic Model of an Air-ride Seat for On-highway Trucks

SAE 2003-01-3419
Simulation of Intelligent Convoy with Autonomous Articulated Commercial Vehicles

SAE 2002-01-3104
Factors Affecting the Friction Coefficients Between Wooden and Plastic Pallets and the Wooden Floor Of A Van-type Semi-trailer

SAE 2002-01-1566
Overview of Carat-4, a Multi-body Simulation and Collision Modeling Program

SAE 2001-01-2755
Factors Affecting the Friction Coefficients Between Wooden Pallets and the Wooden Floor of a Van-type Semi-trailer

SAE 2000-01-3476
Fluid Load Analysis Within the Static Roll Model

RF2000-01
The Post-Kumho Exclusion of a Traffic Accident Reconstruction Expert

SAE 1999-01-3782
A Prototype Computer Based Test System to Test Commercial Vehicle Air Brake Systems: Application and Test Results

SAE 1999-01-3732
Dynamics and Roll Stability of a Loaded Class 8 Tractor-Livestock Semi-Trailer

SAE 973261
Prediction of Steady State Roll Threshold for Loaded Flat Bed Trailers - Theory and Calculation

SAE 971033
Ventilated Brake Rotor Air Flow Investigation

SAE 900106
Skidmark Signatures of ABS-Equipped Passenger Cars

SAE 880066
Combining Scene Data with Trajectory Information for Effective Accident Simulation