A valuation of the environmental performance of vehicles: an analysis and comparison of two methodologies

The European Clean Vehicle Directive was introduced in 2009 to create an obligation on public authorities to take into account the impact of energy consumption, carbon dioxide (CO₂) emissions and pollutant emissions into their purchasing decisions for road transport vehicles. This should stimulate the market for clean and energy-efficient vehicles and improve transport's impact on environment, climate change and energy use. Therefore the so-called ‘Operational Lifetime Cost’ of a vehicle is calculated, divided into the cost for energy consumption, CO₂ and pollutant (nitrous oxide, particulate matter, non-methane hydrocarbons) emissions. In Belgium, a different methodology has been developed to calculate the environmental impact of a vehicle, called ‘Ecoscore’, based on a well-to-wheel approach. More pollutants are included compared to the Clean Vehicle methodology, but also indirect emissions are taken into account. In this paper, both methodologies are compared and used to analyze the environmental performance of passenger cars with different fuel types and from different vehicle segments. Similar rankings between both methodologies are obtained; however, the large impact of energy use (and CO₂ emissions) in the Clean Vehicle methodology disadvantages compressed natural gas cars, as well as diesel cars equipped with particulate filters, compared to the Ecoscore methodology.     

Fully autonomous vehicles: analyzing transportation network performance and operating scenarios in the Greater Toronto Area,Canada

Fully autonomous vehicles (AVs) have the potential to considerably change urban mobility in the future. This study simulates potential AV operating scenarios in the Greater Toronto Area (GTA), Canada, and assesses transportation system performance on a regional level. For each scenario, the base capacities of certain types of road links are modified to simulate the theoretical increase in throughput enabled by AV driving behavior. Another scenario examines driverless parking operations in downtown Toronto. Simulation results indicate that the increased attractiveness of freeways relative to other routes leads to slightly increased average travel distance as vehicles divert to access higher capacity road links. Average travel time is found to decrease by up to one-fifth at the 90% AV market penetration level. Concurrently, localized increases in congestion suggest that proactive transportation planning will be needed to mitigate negative consequences of AV adoption, especially in relation to induced demand for personal automobile travel.     

铁路客车动态管理信息系统研究

在分析现行铁路客车运用、检修管理现状的基础上，提出了实行铁路客车现代化管理的必要性，详细介绍了所开发的铁路客车动态管理信息系统的设计原则、设计方法、主要功能及特点。     

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利用安装GPS设备的浮动车采集动态交通信息，具有数据精度高、覆盖范围广、实时性强等优点。阐述了基于浮动车的交通信息采集系统的原理和组成，针对目前浮动车采样周期主要凭主观经验确定的问题，提出了采样周期优化的理论方法：将浮动车瞬时速度当作随机信号，利用傅立叶变换对其进行频域分析，然后依据Shannon采样定理，确定浮动车的优化采样频率。结果表明：本文方法确定的采样周期可以获得较高的数据采集精度，满足实用要求。     

浅谈南京地铁列车事件记录仪

地铁车辆逐年递增,运营中的地铁列车性能、安全等问题必须高度重视,在地铁车辆上安装事件记录仪非常必要,介绍列车事件记录仪在南京地铁1号线、2号线上的应用。     

40t轴重矿石车的结构稳定性分析

介绍了40 t轴重矿石车的线性及非线性结构稳定性分析,在线性计算中求得屈曲特征值系数,在非线性计算中使用几何非线性及材料非线性进行多载荷步分析,求出精确失稳载荷。采用载荷-位移曲线及载荷-应力曲线判定车体结构的稳定性情况,并就车体稳定性提出了解决方案。     

城市客运车辆舒适性参数的研究

本文从人机工程学观点和车辆的环境因素出发,研究了车内的温度、通风、照明、色彩、噪声、振动、超重等问题对人体的影响,为客运车辆设计时选择舒适性参数提供了依据.     

系列化25型铁路客车CAD系统研制

研制了系列化２５型铁路客车ＣＡＤ系统，利用该系统能够对２５型铁路客车自动进行方案设计，技术设计，施工设计和工程数据库的管理等工作１。中介绍了该系统的组成，主要功能，特点及设计方法。     

空车调整最小费用的合理分摊

借助多人合作对策的思想建立了铁路空车调整问题中最小费用合理分摊的数学模型，给出了建立理想分摊向量和特征函数的一种方法，并提供了具体解法，比较有效地解决了空车调整中最小费用的合理分摊问题，为最优调运方案的实际实施提供了前提和保障。     

接触网检测车振动补偿研究

针对接触检测车实际工况,分析了检测车车体振动的动力学特性,建立了基于运动规律的数学模型,论述了训练样本得出检测车拉出值振动补偿函数的原理和方法。