货车-两轮车前碰撞事故中骑行者运动学响应及损伤分析

为探究货车-两轮车前部碰撞事故中参与双方速度对骑行者运动学响应与损伤的影响,基于MADYMO软件开展事故重建并进行了分析。建立了货车和两轮车的多体碰撞模型,对一起货车前部碰撞两轮车事故进行了事故重建;使用验证后的模型进行了25组不同速度下的全因子仿真试验;分析了不同碰撞速度和骑行速度对骑行者运动学响应和损伤的影响。研究结果表明,骑行者身体旋转幅度会随着两轮车及货车车速的升高而增加;当货车速度超过 20 km/h时,骑行者头部损伤指标 （Head Injury Criterion,HIC） 与胸部3 ms加速度将超过阈值;而当货车速度超过25 km/h时,骑行者下肢接触力也超过阈值;货车速度处于 30～40 km/h时,相同货车速度下,骑行者头部 HIC值出现随着两轮车速度的增加而升高的趋势,而胸部加速度出现相反的趋势。     

Development of a generalised equivalent estimation approach for multi-axle vehicle handling dynamics

This paper devotes analytical effort in developing the 2M equivalent approach to analyse both the effect of vehicle body roll and n-axle handling on vehicle dynamics. The 1M equivalent vehicle 2DOF equation including an equivalent roll effect was derived from the conventional two-axle 3DOF vehicle model. And the 1M equivalent dynamics concepts were calculated to evaluate the steady-state steering, frequency characteristics, and root locus of the two-axle vehicle with only the effect of body roll. This 1M equivalent approach is extended to a three-axle 3DOF model to derive similar 1M equivalent mathematical identities including an equivalent roll effect. The 1M equivalent wheelbases and stability factor with the effect of the third axle or body roll, and 2M equivalent wheelbase and stability factor including both the effect of body roll and the third-axle handling were derived to evaluate the steady-state steering, frequency characteristics, and root locus of the three-axle vehicle. By using the recursive method, the generalised 1M equivalent wheelbase and stability factor with the effect of n-axle handling and 2M equivalent generalised wheelbase and stability factor including both the effect of body roll and n-axle handling were derived to evaluate the steady-state steering, frequency characteristics, and root locus of the n-axle vehicle. The 2M equivalent approach and developed generalised mathematical handling concepts were validated to be useful and could serve as an important tool for estimating both the effect of vehicle body roll and n-axle handling on multi-axle vehicle dynamics.     

Feedback control strategy of a new car-following model based on reducing traffic accident rates

ABSTRACT

To reduce the traffic accident death rate effectively and alleviate the traffic congestion phenomenon, this study proposes a new type of car-following model under the influence of drivers’ time-varying delay response time. Based on Lyapunov function theory, this paper reduces the traffic accident rate problem to the stability issues of the new model. By constructing suitable Lyapunov functions and using the linear matrix inequality method, the stability problem of the new car-following model is studied. The model, under the action of the controller, can effectively restrain traffic congestion. Using the traffic accident rate model proposed by Solomon, compared with the car-following model without the controller, the model under the controller shows a stronger convergence. This also means that the traffic congestion phenomenon has been effectively suppressed while greatly reducing the mortality rate of traffic accidents.     

一种城轨列车的混合动力能量优化控制

近年来,基于质子交换膜燃料电池的混合动力机车越来越受到机车业界的重视。在能量系统中燃料电池充当主要动力源,锂电池和超级电容充当能量支持和存储系统。将系统瞬时氢耗分为燃料电池瞬时氢耗、蓄电池和超级电容等效瞬时氢耗两个部分,建立数学模型,并提出系统瞬时氢耗最小时的能量管理策略,控制着重于计算最佳的燃料电池功率,最大限度地减少混合动力车的氢气消耗。通过仿真测试该能量管理策略对系统能量的优化程度,并与基于经典的比例积分控制策略进行比较。仿真结果表明,在整个驾驶循环期间,节省约5%的氢气消耗。     

承德市道路交通事故易发多发点段分析及治理措施

对承德市境内国道、省道、高速公路辅线的交通事故多发路段、事故多发点进行了详细的分析,根据交通环境、道路状况提出了相应的治理措施。     

沙漠公路交通事故特征及成因分析

自塔克拉玛干沙漠公路1995年全线通车以来,由于沙漠公路特殊的交通环境,交通事故不断发生,并且有逐年增长的趋势。在沙漠公路交通事故统计数据的基础上,对沙漠公路交通事故特征和事故发生原因进行了分析,为沙漠公路营造更加安全的道路交通环境提供了理论依据。     

��ͨ�¹�ǰ�յ�ɢ��������ģ���о�

交通事故现场遗留散落物对事故再现分析有着非常重要的意义。本文在干燥沥青路面进行不同车速下的汽车前照灯模拟碰撞试验，应用VC2000PC加速度计实时测量车辆运动参数，通过分析散落物碎片分布场的形态，选择性提取前照灯碎片分布场的特征参数，构建对应事故再现模型，并对模型的有效性和可行性进行了探讨。     

重庆市交通事故预防和治理机制

在对重庆市道路交通管理及法制建设、具体措施、全面调研的基础上,进一步提出了道路交通事故预防和综合治理的对策.     

等值线法在超声法检测推定混凝土质量中的应用探讨

介绍了应用等值线法检测推定混凝土质量的分析方法,及其推断解释原理,结合工程实例,具体论述了采用该方法的过程及如何运用其判定混凝土质量,并介绍了相关的注意事项。     

基于GIS的城市快速路交通诱导系统研究

介绍了基于GIS的城市快速路交通诱导系统，对系统的功能、结构以及系统的实现进行了详细的介绍，重点介绍了交通状况评价、行程时间预测、异常事故的检测以及交通诱导信息的发布。最后，举例介绍了系统的应用。