This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Reconstruction of Twenty Staged Collisions with PC-Crash's Optimizer
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 05, 2001 by SAE International in United States
Annotation ability available
Event: SAE 2001 World Congress
When vehicle collisions are reconstructed using a discrete kinetic time forward simulation program, many trials have to be performed to reach a point where the simulation results are close to the actual ones. The pre-impact speeds and directions of travel of each vehicle are the main variables that affect the post-impact motion of the vehicles. However, other factors, such as the exact resultant position where the impact forces are exchanged, the vehicle positions with respect to each other at impact, and the coefficient of restitution are important variables that also affect the results. When a number of impact parameters are unknown, a reconstruction can take a great deal of time.
An optimizer tool in PC-Crash is designed to minimize reconstruction time and error by automatically varying a selected number of impact parameters, comparing the resulting simulation for each combination of parameters with the actual incident. For each simulation, it calculates a weighted total error that is based on differences between the actual vehicle positions and angles and those obtained in the simulation. In each subsequent simulation, it changes values in an attempt to minimize the weighted total error. Hundreds of different combinations can be compared in a few minutes.
Twenty staged collisions were reconstructed with the optimizer tool in PC-Crash. These staged collisions had been previously reconstructed with a combination of manual linear momentum calculations combined with the trajectory model in an earlier version of PC-Crash. Differences between the reconstruction simulations and the actual collisions, and methods for minimizing reconstruction errors, are discussed.
|Data from Five Staged Car to Car Collisions and Comparison with Simulations
|Validation of PC-Crash - A Momentum-Based Accident Reconstruction Program
|The Collision and Trajectory Models of PC-CRASH
CitationCliff, W. and Moser, A., "Reconstruction of Twenty Staged Collisions with PC-Crash's Optimizer," SAE Technical Paper 2001-01-0507, 2001, https://doi.org/10.4271/2001-01-0507.
- Smith, R.A. Noga, J.T. “Examples of Staged Collisions in Accident Reconstruction” Proceedings of the ASME Winter Annual Meeting 1980
- Shoemaker, Norris E. “ R esearch I nput for C omputer S imulation of A utomobile C ollisions, Volumes II and III: Staged Collisions” U.S. Department of Transportation Report Nos. National Highway Traffic Safety Administration
- Jones, Ian S. Baum, A.S. “ R esearch I nput for C omputer S imulation of A utomobile C ollisions, Volume IV: Staged Collision Reconstructions”, National Highway Traffic Safety Administration
- Ishikawa, Hirotoshi “Computer Simulation of Automobile Collision - Reconstruction of Accidents” SAE 851729
- Ishikawa, Hirotoshi “Impact Model for Accident Reconstruction - Normal and Tangential Restitution Coefficients” SAE 930654
- Ishikawa, Hirotoshi “Impact Center and Restitution Coefficients for Accident Reconstruction” SAE 940564
- McHenry, Raymond R “Computer Program for Reconstruction of Highway Accidents” SAE 730980
- Cliff WE Montgomery DT “Validation of PC-Crash - A Momentum-Based Accident Reconstruction Program” SAE 960885
- Bailey MN Lawrence JM Fowler SJ Williamson PB Cliff WE Nickel JS “Data from Five Staged Car to Car Collisions and Comparison with Simulations” SAE 2000-01-0849
- Moser, A Steffan, H “The Collision and Trajectory Models of PC-Crash” SAE 960886
- Moser, A Steffan, H “Automatic Optimization of Pre-Impact Parameters Using Post-Impact Trajectories and Rest Positions” SAE 980373
- McHenry, B McHenry, RR “RICSAC-97 - A Reevaluation of the Reference Set of Full Scale Crash Tests” SAE 970961