A simple algorithm for analyzing uncertainty of accident reconstruction results

Proceedings of the Institution of Mechanical Engineers, Part D:

Hua

et al. 2018

Self Cite

In order to obtain a more accurate interval of an accident reconstruction result, two modified experiment design methods were proposed. The first is based on the orthogonal design (OD) and it is named as the orthogonal-based design (OBD), while the other is based on the uniform design (UD) and it is named as the multi-response surface-uniform design (MUD). Furthermore, some conclusions are given according to seven numerical cases: results obtained from the Latin hypercube sampling design (LHS) are the worst, while those obtained from the UD are the last but one, and all are worse than the results obtained from the OBD and the MUD. Furthermore, some conclusions about the number of simulation runs of each design of experiment (DOE) can be given: if the second order response surface model is selected, the number of simulation runs of the LHS is the same as the UD, and all are lesser than the number of simulation runs of the OBD and the MUD in most cases. As for the OBD and the MUD, the number of simulation runs of the OBD is lesser than the number of simulation runs of the MUD, but the MUD can be applied more widely than the OBD. Finally, a true vehicle-pedestrian accident case is given, Pc-Crash was used to reconstruct the accident based on all traces provided by the police, and the interval of the impact velocity of the vehicle was calculated using the OBD, results showed that the research is meaningful in practice.

Section: The Orthogonal Designmentioning

confidence: 99%

Section: The Orthogonal Designmentioning

confidence: 99%

Section: Numerical Casementioning

confidence: 99%

Section: Numerical Casementioning

confidence: 99%

See 2 more Smart Citations

Design of experiment in analyzing uncertainty of simulation results in accident reconstruction

Proceedings of the Institution of Mechanical Engineers, Part D:

Hua

et al. 2018

Self Cite

“…In order to make the reconstructed result more precise and reliable, lots of reconstruction methods are proposed, such as methods based on the braking distance of the vehicle [2,3], the throw distance of the pedestrian [3][4][5], the deformation of the vehicle [6,7], the injury of the human body [8][9][10], simulations (almost all traces), videos and data from some attached active safety equipment [8,[11][12][13][14][15][16][17][18]. Accordingly, many uncertainty analysis methods are also proposed [2,[19][20][21][22][23][24][25][26]. By using these proposed methods, the reconstructed results can be obtained from the uncertain information of traces.…”

Section: Introductionmentioning

confidence: 99%

Methods for fusing uncertain results obtained from different models in accident reconstruction

Forensic Sciences Research

2020

Self Cite

Considering that almost all existing solutions of fusing different reconstructed results require experts' opinions and the issue of how to fuse probabilistic results and mixed results has not been discussed. Two solutions are proposed. The first is based on the Monte Carlo Method (FMCM), while the second is based on the Sub-Interval Technique (FSIT). The method based on FMCM generates sample points according to the distribution of each uncertain result firstly, and then gives out the cumulative distribution function of the final fused result by statistical analysis. The method based on FSIT gets the result fusion interval set according to lower and upper bounds of all interval results and a given length d of each sub-interval firstly, and then calculate the weighted matrix of the result fusion interval. As a result, the cumulative distribution function of the final fused result can also be given out by statistical analysis. Finally, three real accidents are given to demonstrate the methods of FMCM and FSIT, the results of which show that both work well in practice. ARTICLE HISTORY

A case-oriented approach for analyzing the uncertainty of a reconstructed result based on the evidence theory

Cai

et al. 2018

Int J Legal Med

Uncertainty analysis is an effective methodology to improve the reliability of an accident reconstruction result. Many existing methods can be employed in this field, which can confuse a practicing engineer who does not know these methods well. To make the selection easier, a case-oriented approach was proposed based on the evidence theory. Users only need to input uncertain traces and a selected accident reconstruction model to calculate the uncertainty of reconstructed results using the proposed approach. Three basic steps of the case-oriented approach are as follows: first, all types of input traces should be transformed into their evidence form; then, focal elements of the reconstructed result and their corresponding basic probability assignment (BPA) need to be calculated; finally, the belief function (Bel) and plausibility function (Pl) of the reconstructed results are calculated. Three common conditions, which are accidents with all interval traces, accidents with all probabilistic traces, and accidents with interval and probabilistic traces, were discussed based on the basic steps of the case-oriented approach. Furthermore, methods for how to transform different traces to their evidence form, how to calculate the interval of the response efficiently, and how to fuse high conflict evidence were presented. Numerical cases showed that the approach worked well in all conditions. Finally, a vehicle collisions accident case was presented to demonstrate the application of the proposed approach in practice.