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Technical Paper

Application of the Monte Carlo Methods for Stability Analysis within the Accident Reconstruction Software PC-CRASH

2003-03-03
2003-01-0488
As in most accident reconstruction cases, several parameters, like ground friction or inter-vehicle friction are not well known, as well as many vehicle or driver related parameters. ...A method was developed, which allows one to vary multiple parameters based on a Monte Carlo method. The error within the fulfillment of the target function can thus easily be used as a quality indicator for the selected initial conditions. ...Two algorithms are presented, both based on the Monte Carlo approach. The first one serves as an alternative for the optimizer tool and is included in the current version of PC-Crash.
Journal Article

Probabilistic Reanalysis Using Monte Carlo Simulation

2008-04-14
2008-01-0215
PRA calculates very efficiently the system reliability or the average value of an attribute of a design for many probability distributions of the input variables, by performing a single Monte Carlo simulation. In addition, PRA calculates the sensitivity derivatives of the reliability to the parameters of the probability distributions.
Technical Paper

Automated Accident Reconstruction

1975-02-01
750894
The Simulation Model of Automobile Collisions (SMAC) computer program was developed by Calspan Corporation as an aid with which to accurately reconstruct road accidents. Part of the overall objective of the research has been to make the system “user oriented” so that users without an engineering background can operate it with ease. ...This has necessitated developing a START program which automatically runs the SMAC program from a minimum of input data and an iteration routine designed to optimize the input values of velocities to provide a “best fit” reconstruction to the available scene data. A summary of how the START program works is given; however, emphasis is placed in the paper on the development of the iterative routine. ...For each example the results of each successive iteration are given to illustrate the manner in which the program converges to an acceptable reconstruction. This paper is based on research performed under Contract No. DOT-HS-5-01124 with the National Highway Traffic Safety Administration.
Technical Paper

The Effects of Measurement Uncertainty on the Reconstruction of Various Vehicular Collisions

2004-03-08
2004-01-1220
This paper continues a previous study of the effects of uncertainty of measurement upon accident reconstruction. The task is to identify, given the many inevitable errors of observation, the few of greatest import, so that these errors may be reduced, and to document the accuracy of the associated reconstruction. ...In that paper, Finite Difference Analysis (FDA) was reviewed and with the aid of the new data was applied to automotive accident reconstruction. FDA includes identification of “the vital few among the trivial many” (a Pareto analysis) as a guide to the benefits of investigative efforts both past and pending. ...The task is to identify, given the many inevitable errors of observation, the few of greatest import, so that these errors may be reduced, and to document the accuracy of the associated reconstruction. Until recently, it was not for lack of method that such studies could not be properly performed, but for lack of good data on uncertainty of measurement.
Technical Paper

Ground Vehicles Accident Reconstruction using a Procedure based on Genetic Algorithms

2008-10-07
2008-36-0096
In this kind of problems we find the scientific approach of the ground vehicle accident reconstruction. Another theme directly related it is the collisions analysis, as in the context of an accident reconstruction, or in the context of the vehicle crashworthiness, associated to it structural integrity and their occupants' passive safety. ...Another theme directly related it is the collisions analysis, as in the context of an accident reconstruction, or in the context of the vehicle crashworthiness, associated to it structural integrity and their occupants' passive safety. ...This is another effort in the sense of gives a scientific approach to the accident reconstruction and collisions analysis problems, protected and developed by the PUC-Rio Vehicular Systems Group.
Technical Paper

Acoustical Optimization Using Quasi-Monte Carlo Methods and SEA Modeling

2005-05-16
2005-01-2431
For many complicated design challenges, including those involving sophisticated computer simulations and modeling, it is vital to have a systematic and efficient method for exploring available design spaces and finding optimal or near-optimal design solutions. A simple method for relatively quick and straight-forward sampling and subsequent evaluation of design spaces is proposed. No special optimization software or expertise in optimization is required.
Journal Article

Nonlinear Optimization in Vehicular Crash Reconstruction

2015-04-14
2015-01-1433
This paper presents a reconstruction technique in which nonlinear optimization is used in combination with an impact model to quickly and efficiently find a solution to a given set of parameters and conditions to reconstruct a collision. ...These parameters and conditions correspond to known or prescribed collision information (generally from the physical evidence) and can be incorporated into the optimized collision reconstruction technique in a variety of ways including as a prescribed value, through the use of a constraint, as part of a quality function, or possibly as a combination of these means. ...These parameters and conditions correspond to known or prescribed collision information (generally from the physical evidence) and can be incorporated into the optimized collision reconstruction technique in a variety of ways including as a prescribed value, through the use of a constraint, as part of a quality function, or possibly as a combination of these means. This reconstruction technique provides a proper, effective, and efficient means to incorporate data collected by Event Data Recorders (EDR) into a crash reconstruction.
Technical Paper

Optimization Techniques Applied to the Problem of Ground Vehicles Accidents Reconstruction

2005-11-22
2005-01-4063
In this kind of problem we have as an example the scientific approach of the ground vehicle accident reconstruction. Another directly related theme is collisions analysis, either in the context of an accident reconstruction, or in the context of the vehicle crashworthiness, associated to its structural integrity and their occupants’ passive safety. ...Another directly related theme is collisions analysis, either in the context of an accident reconstruction, or in the context of the vehicle crashworthiness, associated to its structural integrity and their occupants’ passive safety.
Technical Paper

An Optimization of Small Unmanned Aerial System (sUAS) Image Based Scanning Techniques for Mapping Accident Sites

2019-04-02
2019-01-0427
Small unmanned aerial systems have gained prominence in their use as tools for mapping the 3-dimensional characteristics of accident sites. Typically, the process of mapping an accident site involves taking a series of overlapping, high resolution photographs of the site, and using photogrammetric software to create a point cloud or mesh of the site. ...These objects represent items commonly found at accident sites. The accident site was then documented with several different unmanned aerial vehicles at differing altitudes, with differing flight patterns, and with different flight control software. ...A mock accident site was created that included a stopped vehicle, a bicycle, and a ladder. These objects represent items commonly found at accident sites.
Technical Paper

Input Force Reconstruction for Vehicle Durability

1996-02-01
960568
In vehicle durability, the determination of accurate input forces can lead to a greater reliance on numerical simulations using analytical models and reduce the need for more expensive and time consuming experimental testing. Traditionally, the input forces are directly measured using load cells. However, in many instances, the direct measurement of force by load cells is either impossible or inaccurate, such as in the case of vehicle body and engine mount loads. To improve the techniques on automobile durability analysis, there is a need to be able to construct the input forces indirectly; i.e., to calculate the input forces by measuring the subsequent structural responses. In essence, the instrumented structure becomes its own load cell. The current study attempts to calculate the body mount loads of a light truck vehicle using the proposed technique. A finite element model of a vehicle body structure is used to locate the areas of load sensitivity.
Technical Paper

IMPACT—Integrated Multiple Program for Accident Crash Trauma

1984-04-01
840868
In general, no single crashes or types of collision are taken into consideration for the optimization, rather a simulated accident world is set up, which is composed of vehicles of different masses, of several types of collision and various speeds.
Technical Paper

Validation of a Model-based Motion Reconstruction Method Developed in the REALMAN Project

2005-06-14
2005-01-2743
Realistic motion reconstruction is the first step for ‘human like’ motion simulation by a digital human. In a recent European research project REALMAN (IST 2000-29357), a model-based motion reconstruction method from external marker trajectories was developed. ...In a recent European research project REALMAN (IST 2000-29357), a model-based motion reconstruction method from external marker trajectories was developed. It consists of two steps. ...The purpose of this paper is to present a validation study of this motion reconstruction method. Its advantages and limitations will also be discussed. Validation was made on two types of seated arm reaching movements carried out at INRETS: seat belt reaches and generic reaches.
Journal Article

Sampling-Based RBDO Using Score Function with Re-Weighting Scheme

2013-04-08
2013-01-0377
In order to alleviate the computation burden, score function together with the Monte Carlo method was used to compute the stochastic sensitivities of reliability functions. In literature, re-weighting schemes were shown to converge faster than the regular Monte Carlo method. ...In literature, re-weighting schemes were shown to converge faster than the regular Monte Carlo method. In this paper, a reweighting scheme together with score function is employed to perform sampling-based stochastic sensitivity analysis to improve the computational efficiency and accuracy.
Technical Paper

Diesel Combustion and Transient Emissions Optimization Using Taguchi Methods

1993-03-01
930600
The optimization of diesel engine design parameters for low emissions using Taguchi Methods is described in this paper. Monte Carlo simulation was performed to predict production emissions distributions. A multi-cylinder development engine equipped with hydraulically-actuated electronically-controlled unit injector (HEUI) fuel system was used for the EPA HD transient cycle tests. ...Taguchi methods were found to be effective in simultaneously optimizing multiple combustion parameters and identifying the effect of each parameter on transient cycle emissions. Monte Carlo simulation proved to be a useful statistical tool for predicting production emissions variability.
Technical Paper

An Excel Based Robust Design Tool for Vehicle Structural Optimization

2004-03-08
2004-01-1124
The RBDO process starts from running simulation at DOE sampling data points, generating surrogate models (response surface) and performing robust and reliability based design optimization on the surrogate models by using Monte Carlo simulation. This paper presents a RBDO framework in Excel enviroment. Within this framework, the engineer can perform DOE sampling, surrogate modeling, robustness assessment, Monte Carlo simulation, robust design and reliability-based optimization with any type of distribution. ...Within this framework, the engineer can perform DOE sampling, surrogate modeling, robustness assessment, Monte Carlo simulation, robust design and reliability-based optimization with any type of distribution.
Technical Paper

A Probabilistic Approach to Multivariate Constrained Robust Design Simulation

1997-10-01
975508
The approach previously proposed by the authors, linking Response Surface Methodology with Monte Carlo Simulations, has revealed itself to be cumbersome and at times impractical for multi-constraint, multi-objective problems. ...The paper critically reviews the combined Response Surface Equation/ Monte Carlo Simulation methodology and compares it against the Advanced Mean Value (AMV) method, one of several Fast Probability Integration techniques. ...The Advanced Mean Value method shows significant time savings over the Response Surface Equation/Monte Carlo Simulation method, and generally yields more accurate CDF distributions. The paper also illustrates how by using the AMV method for distribution generation, robust design solutions to multivariate constrained problems may be obtained.
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