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Comparison of Calculated Speeds for a Yawing and Braking Vehicle to Full-Scale Vehicle Tests
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 16, 2012 by SAE International in United States
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Accurately reconstructing the speed of a yawing and braking vehicle requires an estimate of the varying rates at which the vehicle decelerated. This paper explores the accuracy of several approaches to making this calculation. The first approach uses the Bakker-Nyborg-Pacejka (BNP) tire force model in conjunction with the Nicolas-Comstock-Brach (NCB) combined tire force equations to calculate a yawing and braking vehicle's deceleration rate. Application of this model in a crash reconstruction context will typically require the use of generic tire model parameters, and so, the research in this paper explored the accuracy of using such generic parameters. The paper then examines a simpler equation for calculating a yawing and braking vehicle's deceleration rate which was proposed by Martinez and Schlueter in a 1996 paper. It is demonstrated that this equation exhibits physically unrealistic behavior that precludes it from being used to accurately determine a vehicle's deceleration rate. Finally, the paper moves on to consider an equation that is attributed to the CRASH program in the 2010 edition of Traffic Crash Reconstruction by Lynn Fricke. This equation is nearly as simple as the Martinez and Schlueter equation, but its behavior is more reasonable.
The BNP/NCB and the CRASH models are then used to calculate vehicle deceleration rates and speeds for two full-scale vehicle tests run by the authors, both involving yawing and braking vehicles. Braking levels for the vehicles in these tests were calculated using analysis of tire mark striations. The results of these speed calculations are compared to the measured speeds for each of those full-scale tests.
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CitationCarter, N., Beauchamp, G., and Rose, N., "Comparison of Calculated Speeds for a Yawing and Braking Vehicle to Full-Scale Vehicle Tests," SAE Technical Paper 2012-01-0620, 2012, https://doi.org/10.4271/2012-01-0620.
- Bakker, E. Nyborg, L. Pacejka, H. “Tyre Modelling for Use in Vehicle Dynamics Studies,” SAE Technical Paper 870421 1987 10.4271/870421
- Brach, R. Brach, R. “Modeling Combined Braking and Steering Tire Forces,” SAE Technical Paper 2000-01-0357 2000 10.4271/2000-01-0357
- Brach, R.M. Brach, R.M. “Vehicle Accident Analysis and Reconstruction Methods,” SAE International 978-0768007763 2005
- Brach, Raymond M. Brach, R. Matthew “Tire Models used in Accident Reconstruction Vehicle Motion Simulation,” XVII Europäischen für Unfallforschung und Unfallanalyse (EVU) - Conference Nice, France 2008
- Brach, R. Brach, R. “Tire Models for Vehicle Dynamic Simulation and Accident Reconstruction,” SAE Technical Paper 2009-01-0102 2009 10.4271/2009-01-0102
- Martinez, J. Schlueter, R. “A Primer on the Reconstruction and Presentation of Rollover Accidents,” SAE Technical Paper 960647 1996 10.4271/960647
- Marine, M. Wirth, J. Thomas, T. “Characteristics of On-Road Rollovers,” SAE Technical Paper 1999-01-0122 1999 10.4271/1999-01-0122
- Fricke, Lynn B. Traffic Crash Reconstruction Second Northwestern University Center for Public Safety 2010
- Beauchamp, G. Hessel, D. Rose, N. Fenton, S. et al. “Determining Vehicle Steering and Braking from Yaw Mark Striations,” SAE Int. J. Passeng. Cars - Mech. Syst. 2 1 291 307 2009 10.4271/2009-01-0092
- Cliff, William E. Bowler, James J. “The Measured Rolling Resistance of Vehicles for Accident Reconstruction,” Society of Automotive Engineers Paper Number 980368 1998
- Daily, John Shigemura, Nathan Daily, Jeremy “Fundamentals of Traffic Crash Reconstruction,” Institute of Police Technology and Management 1884566634 2006