基于轮胎印迹的事故再现方法研究

首先建立了相机的三维摄影测量模型,用于轮胎印迹的准确勘测和建模。然后建立了车辆运动及碰撞过程中的动力学模型,用以模拟车辆在碰撞前、碰撞过程及碰撞后的运动轨迹,和摄影测量得到的轮胎印迹模型比较,采用轨迹优化的方法实现交通事故在计算机上的三维模拟再现。最后通过在典型事故再现中的应用阐述此方法的应用价值。     

基于动量定理的汽车单次三维碰撞运动状态参数计算模型

为了给汽车单次三维碰撞事故的碰撞车速推算提供算法,并为汽车运动轨迹再现提供初始条件,在借鉴已有的二维碰撞运动状态参数计算模型的基础上,将碰撞冲量推广至三维空间。以动量定理为理论基础,结合PC-Crash事故再现软件的碰撞分析方法,提出了汽车三维运动临界条件,推导了汽车三维运动状态参数计算模型。以实际事故案例为研究对象,将基于上述模型开发的事故再现分析系统的计算结果与PC-Crash软件计算结果进行了对比,并将事故再现分析结果与实际案例中车辆翻滚方式进行了对比。结果表明:所提出的汽车单次三维碰撞运动状态参数计算模型能够有效计算汽车三维碰撞速度参数与角速度参数。     

大客车对行人碰撞事故再现研究

利用数值模型仿真试验,研究再现大客车与行人碰撞事故的方法。并将该方法应用到一次真实交通事故中去,初步验证了该模型和方法的可行性。将行人抛距分析方法引入事故再现分析,并结合仿真结果,建立新的适合该类事故的行人抛距与车速关系模型。     

推算汽车碰撞速度的两种图解法

本文根据动量平衡和动量守恒定律的基本原理，提出了两种推算碰撞前汽车动量或碰撞速度的图解方法，这两种图解方法绘制简单，适合编程由计算机制作，为交通事故再现推测碰撞速度提供了一种简单实用的方法。     

Human body modelling for traffic accident analysis

A traffic accident is a complex phenomenon with vehicles and human beings involved. During a collision, the vehicle occupant is exposed to substantial loads, which can cause the occupant injuries that depend on the level of passive safety, as well as on the occupant's individual characteristics. Correct estimation of injury severity demands a validated human body model and known impact conditions. A human body modelling procedure for the purpose of accident analysis is introduced. The occupant body has been modelled as a multibody system with rigid body segments connected. Geometrical and inertial properties of individual body segments were estimated using computed tomography. Frontal impact conditions were simulated on a sled test facility, while the human body dynamic response was measured. Comparison of experimental data and computer simulation revealed an influence of joint resistive properties on the occupant motion in collisions. The difference between measured and simulated response was minimised using optimisation method. Individualised human body modelling procedure enabled better prediction of the occupant motion during vehicle collision and thus more precise estimation of possible injuries in real-life traffic accidents.     

Energy loss in vehicle collisions from permanent deformation: an extension of the ‘Triangle Method’

The paper presents an extension of the ‘Triangle Method’, to evaluate the energy loss in road accidents. The improvement of the method allows to evaluate the energy loss by both the colliding vehicles in car to car impacts, considering the main possible configurations of accident. The limits of applicability of the method are those of the Campbell's method [K.E. Campbell, Energy basis for collision severity, SAE paper 740565, Society of Automotive Engineers, Inc., Warrendale, Pennsylvania, 1974; A.G. Fonda, Principles of crush energy determination, SAE 1999-01-0106, Society of Automotive Engineers, Inc., Warrendale, Pennsylvania, 1999; N.S. Tumbas and R.A. Smith, Measurement protocol for quantifying vehicle damage from an energy basis point of view, SAE paper 880072, Society of Automotive Engineers, Inc., Warrendale, Pennsylvania, 1988; G.A. Nystrom, G. Kost, and S.M. Werner, Stiffness parameters for vehicle collision analysis, SAE paper 910119, Society of Automotive Engineers, Inc., Warrendale, Pennsylvania, 1991; J.A. Neptune, G.Y. Blair, and J.E. Flynn, A method for quantifying vehicle crush stiffness coefficients, SAE paper 920607, Society of Automotive Engineers, Inc., Warrendale, Pennsylvania, 1992]. The advantage over the usual methods are that the method does not require the knowledge of the stiffness of the vehicles and only two parameters are needed to define the damage geometry. The latter can be easily evaluated by visual inspection on a suitable photographical documentation of the damages, without the need to perform any direct measurement on the vehicles. Furthermore, the method can be used also in the very frequent cases in which some of the damage data about one of the vehicles are missing or in accidents involving lateral parts of the vehicle as zones near the wheels or the front, that have different behaviour from that tested in the classical crash tests. The error analysis developed shows that the errors due to the application of the extended method are negligible and fall in the range generally considered acceptable in road accident reconstruction.     

基于不确定度理论的汽车与自行车侧面碰撞速度估算

基于不确定度理论,针对汽车-自行车侧撞事故的速度计算模型建立了相应的不确定度分析方法.结合事故再现模型,运用方差合成理论并考虑自行车抛距与行人抛距间的相关性,将各标准不确定度分量进行合成,最终得到车速估算的合成标准不确定度和扩展不确定度,由此给出较合理的车速估算结果.通过一个典型事故分析案例,验证了该方法的正确性.     

交通事故再现过程中车辆模型的读取与控制

为了实现交通事故再现过程中对车辆三维模型的读取与控制,本文运用三维建模软件（3DMAX）对车辆进行建模,在VC＋＋及OpenGL环境下读取并重绘模型,通过程序对模型进行控制。     

基于PC-Crash的轿车-行人高速碰撞仿真模型

利用PC-Crash模拟高速条件下轿车与行人后部的碰撞过程,试验假人选择PC-Crash标准成年假人模型,碰撞后汽车驾驶员未采取紧急制动措施,仍然按照碰撞时刻的车速行驶,试验车速区间选择75~155 km/h。研究了不同碰撞车速下行人的第一落地点和最终静止点抛距变化规律,分析了行人头部在事故中所受到的碰撞接触力的变化规律,在此基础上建立汽车行人高速碰撞模型并进行对比验证。     

Vehicle Motion Analysis in Relation to Vehicle Safety

The influence of vehicle handling on the possible avoidance of accident situations is discussed. lit is shown that accident reconstruction at present does not provide the necessary information to relate the cause of accidents to the lack of road worthiness of vehicles. It follows that the vehicle behavior in proximity of its performance limit must be determined in order to infer its accident avoidance potential.

The paper presents a review of the state-of-the-art of vehicle modeling, simulation of vehicle maneuvers and full scale testing. The application of the direct method of the stability theory is suggested as a possible means of obtaining performance limit envelopes which are necessary for establishing standards of the performance of vehicles.     

IMAGE MODELER的汽车碰撞变形区域的三维重建

汽车碰撞变形区域的测量是交通事故处理及事故再现的重要工作,利用基于图像的三维建模软件Image Modeler．可以直接通过按照一定原则拍摄的二维照片,恢复和重构三维模型,有利于提高变形车辆测量的效率和精度。文章介绍了基于二维照片的三维建模基本原理,阐述了利用该技术实现汽车碰撞变形区域三维重建的过程,实验表明,此方法能提供详细的汽车碰撞变形区域描述,对交通事故的公平处理和科学研究提供有力的参考。     

基于有限元模型的汽车-行人碰撞事故重构研究

利用Hypermesh和Pamcrash软件,建立第50百分位行人下肢有限元模型和简化的厢式货车有限元模型,重构厢式货车倒车时与行人碰撞的交通事故案例,通过将模拟得到的行人损伤情况,比较韧带和骨骼的损伤,与医院给出的伤者诊断结果进行对比来确定初始参数,得出有限元仿真模拟碰撞事故的有效方法.结果表明,通过有限元仿真进行碰...     

汽车滚翻事故的再现分析方法

汽车滚翻事故的再现分析是一个复杂的过程,需要仔细考察汽车滚翻过程的3个阶段,包括侧滑阶段、侧翻阶段和翻滚阶段.论述了各阶段再现分析常用的模型和方法,介绍了一般计算方法或再现步骤,以及二维和三维再现的目标和技术要点,使用计算机辅助事故再现.再现分析滚翻事故中汽车运动过程及其瞬时速度和空间姿态,能够为事故处理和责任认定提供科学依据,并有助于改进车身机构和车内被动安全装置的设计.     

Vehicle Motion Analysis in Relation to Vehicle Safety

SUMMARY

The influence of vehicle handling on the possible avoidance of accident situations is discussed. lit is shown that accident reconstruction at present does not provide the necessary information to relate the cause of accidents to the lack of road worthiness of vehicles. It follows that the vehicle behavior in proximity of its performance limit must be determined in order to infer its accident avoidance potential.

The paper presents a review of the state-of-the-art of vehicle modeling, simulation of vehicle maneuvers and full scale testing. The application of the direct method of the stability theory is suggested as a possible means of obtaining performance limit envelopes which are necessary for establishing standards of the performance of vehicles.     

汽车正面碰撞事故车速预测模型仿真研究

为了能有效准确地根据事故现场情况预测出碰撞前车辆的运行车速情况,文章利用反推算法,遵循相关物理定律,构建正面碰撞事故中车辆相关参数及道路条件与车速的函数关系,并基于Visual Basic平台搭建车速预测模型并进行实测验证。结果表明,所构建模型的误差率较低,所构建模型、系统是正确高效的,可用于正面碰撞事故的车速预测研究工作。     

A fuzzy approach to reconstructing vehicle–pedestrian collisions

Vehicle–pedestrian collision is one of the most frequent and most severe types of road accident. Many models, both theoretical and empirical, have been developed over the last 30 years to reconstruct this type of impact, but not all of them yield accurate results, with a spread averaging about ±10?km/h. Many multibody software systems have been developed as well. They are very accurate and, when all of the parameters required by the software are available, they are the best methods to reconstruct the collision. However, complete knowledge of the precise dynamics of pedestrian motion throughout the trajectory is not necessary. For a court expert, the data on conditions of pre-impact, impact and rest position are usually sufficient to make an adequate survey. The fuzzy approach presented in this paper is used to calculate the velocity of the impacting vehicle, considering the main parameters, all collectable at the scene of the accident, with a precision of about 3?km/h. Accordingly, this methodology represents a suitable tool for the purpose of accident reconstruction.     

道路交通事故分析发展研究

近些年,我国交通事故量一直居高不下,而事故发生时车辆运行速度是分析事故原因、认定事故责任的重要内容,涉及保险理赔、法院审判等各个环节。目前分析事故原因,进行事故再现的主要途径是委托具有相关资质的事故鉴定机构进行速度重建,使用的方法主要有基于经验公式的事故重建、基于视频图像技术的事故重建、基于车载记录数据的事故重建和基于模拟软件的事故重建。文章主要介绍了交通事故分析的基本方法和发展方向。     

结合伤情的事故再现新方法研究

采用FC-Crash对道路交通事故进行重构已是比较成熟的方法,从中可以获取事故车辆的三维加速度与角加速度波形,但无法模拟出乘员的伤情指标,而Madymo软件是建立包含车体、安全带、安全气囊、假人在内的约束系统模型,在给定的加速度下可以计算出人员的伤害指标。故将PC—Crash与Madymo进行耦合计算,即可获得事故车辆在事故过程中的运动参数,再现驾乘者的运动响应,进而得到人员的伤情指标。这一新的事故再现方法的研究结果表明:PC-Crash与Madymo的耦合计算可较为准确地再现事故车辆的减速和旋转运动状态,以及驾乘人员的响应运动状态,对结合致伤机理深入分析事故原因具有重要的意义,也可为交通事故鉴定提供新思路。     

电动二轮车驾驶人头部损伤再现不确定性方法

为了减少交通事故中不确定性信息在受伤害者损伤再现中造成的不利影响,采用拉丁超立方(LHS)试验设计和响应面蒙特卡洛相结合的方法对电动二轮车驾驶人头部损伤再现进行损伤不确定性分析。首先采用多体系统动力学方法对具有详细事故信息(含视频信息)和损伤记录的2起电动二轮车事故中的汽车碰撞速度进行再现和不确定性分析,并对比事故信息(视频信息、最终位置、电动二轮车驾驶人的运动学),进而验证事故再现结果的有效性。在此基础上,应用有限元方法将获得的电动二轮车驾驶人头部碰撞的边界条件加载至THUMS人体头部有限元模型,分析电动二轮车驾驶人头部损伤参数的不确定性与简明损伤准则AIS累计频率的分布关系,并对比电动二轮车事故案例中电动二轮车驾驶人的头部损伤法医鉴定记录。研究结果表明:蒙特卡洛不确定性分析方法能够较准确地预测电动二轮车事故中的汽车碰撞车速,采用该分析方法获得的电动二轮车驾驶人头部损伤等级与法医鉴定的脑部损伤记录高度吻合;蒙特卡洛不确定性分析方法可以适用于评估电动二轮车事故中电动二轮车驾驶人的头部损伤等级,研究结果可为电动二轮车驾驶人头部损伤研究提供理论依据和实证方法。     

变形车辆自标定三维重建的建模研究

变形车辆测量是道路交通事故再现的重要基础性工作。建立基于普通数码相机的事故变形车辆自标定三维重建模型,可以避免在现场设置标定物,有利于提高变形车辆的勘测效率和三维重建设备的使用方便性。研究了基于基础矩阵估计的事故变形车辆摄影图像自标定三维模型,并分析了其实现过程。实验表明,自标定三维重建能为事故再现提供详细的车辆变形描述。