车对车正面偏置碰撞试验研究与探讨

模拟现实交通事故中的碰撞,展开车对车偏置碰撞试验,对试验中特殊的设施、准备方法、试验控制及试验结果进行研究与分析,并对如何进一步展开两车正碰试验作了探讨。     

轮胎模型刚度对前部偏置碰撞结果的影响

建立了整车碰撞模型中的轮胎模型后,通过调整模型参数,使模拟的轮胎刚度特性曲线近似于试验的轮胎刚度特性曲线,并应用于整车前部偏置碰撞模拟中,分析轮胎刚度对偏置碰撞结果的影响.结果表明,轮胎刚度对碰撞过程整车加速度、截面力、防火墙侵入量等均有一定的影响.     

重型卡车和轿车的碰撞相容性分析

随着我国经济的发展,汽车保有量也在大幅度地增加,随之而来的交通事故等各项指标均持续增长,交通安全状况日益恶化,尤其是在我国混合交通模式为主的交通环境中,常常造成卡车撞击轿车的事故,但由于卡车的质量大、碰撞高度较高,在碰撞中卡车的损伤较小,而轿车所受的伤害却是非常惨烈的。这     

基于碰撞相容性因素的车辆追尾事故深入数据分析

为详细了解北京市追尾事故车辆的分类对比情况,基于车辆碰撞相容性因素构建了追尾事故的深入数据分析模型,包括追尾事故车辆的基本类型、结构形式及几何特征对比、车辆碰撞损坏特点、车内乘员伤害情况及其相关性等方面内容。利用真实交通事故案例对车辆碰撞相容性相关因素进行统计分析,为车辆追尾事故的预防与伤害减轻等项研究提供参考,指出今后研究的侧重点。     

长城某车辆碰撞相容性研究

本文阐述了车对车碰撞相容性研究的重要性,介绍了国际上相容性研究动态,以及长城某轿车在碰撞仿真分析及实车试验中进行碰撞相容性研究的一些情况。     

基于吸能率的车辆碰撞相容性分析及优化设计

开展了车辆防撞性和碰撞相容性的设计分析,提出了一种新型相容性指标——吸能率rE并验证其合理性,该指标可望解决现有评价指标对车辆侵入程度的量化缺乏连续性和普适性的问题。然后对参数化模型进行自动更新,从而进行设计变量优化求解,最终形成一套集成设计方法。工程实例显示,提出的吸能率指标rE可实现对目标车辆攻击性程度的连续量化评估,参数化优化策略可有效提升车辆碰撞相容性和设计优化效率。     

汽车的碰撞相容性研究

阐述了汽车碰撞相容性的概念和研究目的,并用简单的模型进行了理论分析,提出了改善相容性的一些措施。     

一种应对MPDB工况碰撞相容性的车辆前端设计研究

Euro NCAP(New Car Assessment Program,欧盟新车评价规程)在2020年加入正面MPDB(Mobile Progressive Deformable Barrier,正面可变移动壁障)碰撞工况,并加入碰撞相容性评价。对MPDB碰撞工况及碰撞相容性评价规程进行了简要介绍,识别出现有某车型在MPDB工况试验后碰撞相容性的典型问题;对一种应对MPDB工况碰撞相容性同时兼顾其他典型碰撞工况的车辆前端优化设计思路与过程进行介绍说明,为其他需满足相应评价规程要求的车型提供了设计参考。     

车身钣件材料对正面偏置碰撞安全性的影响

采用正交试验方法分析车身钣件材料变更对汽车正面偏置碰撞的安全性的影响程度。建立了某车的正面偏置碰撞模型,提出了对偏撞安全性的评价指标,对多个不同钣件材料更换组合进行了仿真分析。最终得出了各钣件材料变更对各个评价指标的影响程度和排序。     

轿车正面碰撞的计算机模拟

本文采用有限元分析的方法模拟轿车正面碰撞过程,通过试验曲线验证计算机模型,最后给出车身结构改进措施.     

On the overriding issue of train front end collision in rail vehicle dynamics

A three-dimensional dynamic model of crashed vehicles coupled with moving tracks is developed to research the dynamic behaviour of the train front end collision on tangent tracks. The three-dimensional dynamic model consists of a crashed vehicle model, moving track models, a simple wheel–rail contact model, a velocity-based coupler model and the model of energy absorption and anti-climbing devices. The vector method dealing with the nonlinear wheel–rail geometry is put forward in the paper. The developed model is applicable in the scope that central collisions occur on tangent tracks at low speeds. The examples of the vehicle impacting with a rigid wall and the train front end collision are carried out to obtain the dynamic responses of vehicles. The overriding issue is studied on the basis of the wheel rise in train collisions. The results show that the second bogie of the first colliding vehicle possesses the maximal wheel rise. The wheel rise increases with the increase of vehicles. However, the number of vehicles has tiny influence on the overriding in train collisions at low speeds. On the contrary, the impact speed has significant influence on the overriding in train collisions. The wheel rise increases rapidly if the impact speed is close to the critical speed of overriding. The large wheel rise is principally generated by the great coupler force related to the rigid impact in the axial direction.     

轻型汽车前部偏置碰撞特性研究

从汽车前部偏置碰撞动量分析入手提出碰撞前后汽车运动状态间的关系，得出结论：汽车碰撞时９５％以上的能量均由汽车车体变形所吸收；碰撞后汽车的运动状态（即汽车运动的速度及角速度）与汽车碰撞位置有关，与汽车碰撞前的速度成正比。该结论通过ＡＮＳＹＳ／ＬＳ－ＤＹＮＡ３Ｄ有限元模拟计算获得验证。     

Estimation of lateral offset and drift angle for application in secondary collision avoidance system

Recent reports show that the secondary collision on the road gives much higher fatality rate than the other traffic accidents. Many studies have been carried out to prevent the secondary accidents and as a result automotive companies began to introduce brake-based secondary collision avoidance systems. To prevent the secondary accidents it is important to monitor and control the lateral deviation of the vehicle after the primary collision. An estimator for the vehicle’s lateral offset and drift angle based on the in-vehicle sensors and the camera was developed in this paper. By employing sensor fusion scheme and applying extended Kalman filter, the estimator has been designed so that it works even when the camera loses the image of the lanes due to sudden change of the vehicle’s heading angle. For validation of the estimator, simulation has been carried out on various collision scenarios. The simulation results indicated that the estimator of this paper could calculate the vehicle’s lateral deviation with robustness that may be required for application in the secondary collision avoidance systems.     

从PNGV到FreedomCAR——看美国的新一代汽车开发项目

2002年初，美国政府宣布成立一个开发下一代汽车的新项目，称为自由车项目，并取代原先的PNGV项目，本文介绍了该新项目出台的背景，并回顾了PNGV的成果。     

Unified decision-making and control for highway collision avoidance using active front steer and individual wheel torque control

ABSTRACT

Collision avoidance is a crucial function for all ground vehicles, and using integrated chassis systems to support the driver presents a growing opportunity in active safety. With actuators such as in-wheel electric motors, active front steer and individual wheel brake control, there is an opportunity to develop integrated chassis systems that fully support the driver in safety critical situations. Here we consider the scenario of an impending frontal collision with a stationary or slower moving vehicle in the same driving lane. Traditionally, researchers have approached the required collision avoidance manoeuver as a hierarchical scheme, which separates the decision-making, path planning and path tracking. In this context, a key decision is whether to perform straight-line braking, or steer to change lanes, or indeed perform combined braking and steering. This paper approaches the collision avoidance directly from the perspective of constrained dynamic optimisation, using a single optimisation procedure to cover these aspects within a single online optimisation scheme of model predictive control (MPC). While the new approach is demonstrated in the context of a fully autonomous safety system, it is expected that the same approach can incorporate driver inputs as additional constraints, yielding a flexible and coherent driver assistance system.     

Evaluation of automotive forward collision warning and collision avoidance algorithms

Collision warning/collision avoidance (CW/CA) systems target a major crash type and their development is a major thrust of the Intelligent Vehicle Initiative. They are a natural extension of adaptive cruise control systems already available on many car models. Many CW/CA algorithms have recently been proposed but the existing literature mainly focuses on algorithm development. Evaluations of these algorithms have been usually based on subjective ratings. The main contribution of this paper is the utilization of a naturalistic driving data set for the evaluation of CW/CA algorithms. We first collect manual driving data from the ICCFOT project, then process the data by Kalman smoothing, and finally identify 'threatening' and 'safe' data sets according to vehicle brake inputs and vehicle range behavior. Five CW/CA algorithms published in the literature are evaluated against the identified data sets. The performance of these algorithms is determined through a performance metric commonly used in signal detection and information retrieval under unbalanced data population.     

Evaluation of automotive forward collision warning and collision avoidance algorithms

Collision warning/collision avoidance (CW/CA) systems target a major crash type and their development is a major thrust of the Intelligent Vehicle Initiative. They are a natural extension of adaptive cruise control systems already available on many car models. Many CW/CA algorithms have recently been proposed but the existing literature mainly focuses on algorithm development. Evaluations of these algorithms have been usually based on subjective ratings. The main contribution of this paper is the utilization of a naturalistic driving data set for the evaluation of CW/CA algorithms. We first collect manual driving data from the ICCFOT project, then process the data by Kalman smoothing, and finally identify ‘threatening’ and ‘safe’ data sets according to vehicle brake inputs and vehicle range behavior. Five CW/CA algorithms published in the literature are evaluated against the identified data sets. The performance of these algorithms is determined through a performance metric commonly used in signal detection and information retrieval under unbalanced data population.     

Analysis of driver response to collision warning during car following

This paper describes research on drivers’ responses to a forward vehicle collision warning by driving simulator experiments in which 36 subjects were disposed randomly to the following three kinds of dangerous scenes while the subjects were intentionally distracted: closing to a preceding vehicle, sudden cut-in of a vehicle from an adjacent lane, and lane departure of own vehicle. The responses of the subjects to the warning against cut-in vehicles were analyzed. It is shown that the subjects could take proper evasive action, but the average brake response time was longer than those for simpler scenario tests. It is also verified that there were statistically significant effects of warning sound on the subjects’ response times.     

Fracture properties of aluminum foam crash box

This study investigates the compression property experiment to examine impact absorption when aluminum foam is applied to crash box in order to absorb impact energy in car crash with low speed. The result of compression property experiment shows that case 6, which involves the buckling that collapses into 5-layer structure, is the best model with regard to impact absorption. This study analyzes impact characteristics according to the structure of crash box which influences such factors as damage and safety of vehicles. As the simulation result can be agreed with experimental graph, all experimental data at this study are verified. These experimental results can be applied into real field effectively. It also proposes the effective design to improve impact performance by analyzing the property of crash box through its compressive test.