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Speedometers and Collision Reconstruction
Technical Paper
2017-01-1412
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Various mechanisms have been used to drive speedometers and other instrument gauges. This paper reviews the mechanisms used; in particular investigates the ability of stepper motors which have become the most common instrument motor in the last decade to freeze at the apparent reading prior to impact. Stepper motors require power to drive the needle to any indicated position, including having to return it to zero. Hence if power to the instrument is lost as a result of a collision, there is no power to move the needle and it should be left at the reading shown at the moment the power was lost. However, not all stepper motor instruments are the same and before accepting the reading, a number of criteria need to be considered to give a level of confidence in the result. As part of recent ITAI (Institute of Traffic Accident Investigators) crash test events in the UK, a number of instrument clusters were installed in vehicles to simulate both frontal and side impacts. Impact speeds were recorded up to 75mph (120Kph). The results show that some instrument types will hold their pre-impact position even during high speed side impacts while others produce erratic readings.
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Citation
Goddard, C. and Price, D., "Speedometers and Collision Reconstruction," SAE Technical Paper 2017-01-1412, 2017, https://doi.org/10.4271/2017-01-1412.Data Sets - Support Documents
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References
- http://www.coregravity.com/assets/images/all_phase_stepper_motor.JPG
- ISO 7637-2: 2004(E) Road Vehicles – Electrical disturbances from conduction and coupling
- David Price
- ITAI Contact 77 April 2004
- Hague D Accuracy of retained Speedometer Readings Proceedings of the 11th Institute of Traffic Accident Investigators International Conference Birmingham 2014
- Anderson R.D Post Collision Speedometer Readings and Vehicle Impact Speeds, Collision 5 2 32 41 2010
- Kuranowski A Reliable determination of impact velocity on the basis of indications of the speedometer stopped after the collision Proceedings of the 6th International Scientific Conference Transbaltica 2009
- Wang , Q. and Gabler , H.C. Accuracy of Vehicle Frontal Stiffness Estimates for Crash Reconstuction Proceedings of the Twentieth International Conference on Enhanced Safety of Vehicles, Paper No. 07-0513 Lyons, France June 2007
- Dipl.-Ing. Marvin Lammert Vehicle Accelerations and Times of Impact based on a Data Analysis of Accident Data Recorders Proceedings of the 22nd Annual Conference EVU
- Yuan Q , Li Y , Xing S & Lv Y Correlation Between Residual Speedometer Needle Reading And Impact Speed Of Vehicles In Traffic Accidents International Journal of Automotive Technology 16 6 1057 1063 2015