Computerized crash reconstruction of real world crashes using optimization methodology

Hasija, Vikas; Takhounts, Erik G.; Ridella, Stephen A.

Affiliations

Abstract

Computerized crash reconstruction of real world crashes involves dealing with a lot of unknown parameters and as such the reconstruction problem cannot be solved deterministically as was shown using a parametric methodology presented in our previous ESV paper titled “Computational Analysis of Real World Crashes: A Basis for Accident Reconstruction Methodology.” This paper introduces a modified version of the parametric methodology, which involves using an optimization scheme to derive an optimal solution for the reconstruction problem in a given range of unknown parameters. Real world crashes were selected from the CIREN database and were solved using the proposed methodology. Human-Vehicle-Environment (HVE) software was used to generate the crash pulse where EDR data were missing. The problem was set up in MADYMO. During the set up, the unknown parameters were identified. ModeFRONTIER software was used for optimization. The identified unknown parameters were treated as design variables. The objective function and the constraints were defined such that they minimize the differences in injuries and occupant-vehicle contacts between the real world data and the model prediction. Since the objective function has a great effect on the final solution, a normalized form of the objective function, weighted based on the AIS level of the injuries sustained by the occupant, was formed in this study. A genetic algorithm with Sobol DOE (Design of Experiments) was used for optimization. Results of the simulations showed that the optimal solution correctly predicted both the occupant-vehicle contacts and the injuries sustained by the occupant. By viewing the occupant motion inside the vehicle during the crash, better occupant protection systems can be devised. Correlation studies were also carried out to find the critical parameters affecting the solution. In addition, a best case scenario study was carried out to find, using optimization, the design changes that could help mitigate all or some of the injuries sustained by the occupant.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0415.pdf

Cited Works (9)

Year	Entry
1999	Eppinger R, Sun E, Bandak F, Haffner M, Khaewpong N, Maltese M, Kuppa S, Nguyen T, Takhounts E, Tannous R, Zhang A, Saul R. Development of Improved Injury Criteria for the Assessment of Advanced Automotive Restraint Systems - II. Washington, DC: National Highway Traffic Safety Administration (NHTSA); November 1999.
2007	Hasija V, Takhounts EG, Ridella SA. Computational analysis of real world crashes: a basis for accident reconstruction methodology. In: Proceedings of the 20th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 18-21, 2007; Lyon, France.
2006	Salzar RS, Bass CRD, Kent R, Millington S, Davis M, Lucas S, Rudd R, Folk B, Donnellan L, Murakami D, Kobayashi S. Development of injury criteria for pelvic fracture in frontal crashes. Traffic Inj Prev. September 2006;7(3):299-305.
2005	Franklyn M, Fildes B, Zhang L, Yang K, Sparke L. Analysis of finite element models for head injury investigation: reconstruction of four real-world impacts. Stapp Car Crash J. 2005;49:1-32. SAE 2005-22-0001.
1989	Viano DC, Lau IV, Asbury C, King AI, Begeman P. Biomechanics of the human chest, abdomen, and pelvis in lateral impact. Accid Anal Prev. 1989;21(6):553-574.
2003	Pellman EJ, Viano DC, Tucker A, Casson IR, Waeckerle JF. Concussion in professional football: reconstruction of game impacts and injuries. Neurosurgery. October 2003;53(4):799-814.
2006	Marjoux D, Baumgartner D, Deck C, Willinger R. Head injury prediction capability of the HIC, HIP, SIMON and ULP criteria. In: Proceedings of the 2006 International IRCOBI Conference on the Biomechanics of Impact. September 20-22, 2006; Madrid, Spain.143-157.
2008	Takhounts EG, Ridella SA, Hasija V, Tannous RE, Campbell JQ, Malone D, Danelson K, Stitzel J, Rowson S, Duma S. Investigation of traumatic brain injuries using the next generation of Simulated Injury Monitor (SIMon) finite element head model. Stapp Car Crash J. 2008;52:1-31. SAE 2008-22-0001.
2001	Kuppa S, Wang J, Haffner M, Eppinger R. Lower extremity injuries and associated injury criteria. In: Proceedings of the 17th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 4-7, 2001; Amsterdam, The Netherlands.