城市轨道交通车辆蓄电池亏电故障原因分析与维护策略

随着我国科学技术的飞速发展,城市轨道交通车辆已经成为了现代交通中的重要组成部分。本文以某市地铁1号线0215列车为例,就城市轨道交通车辆蓄电池亏电故障原因分析和维护策略展开探讨。     

城市轨道交通车辆段规划设计研究

以城市轨道交通车辆段规划设计为切入点,从地理位置选择、基础设施布局、车辆进出口设计、检修设备配置、安全防护和环境保护措施等方面出发,提出一系列设计策略和原则,旨在为城市轨道交通车辆段规划提供参考,促进城市轨道交通的可持续发展,进一步满足民众高效、安全、环保的出行需求。     

我国城市轨道交通车辆的发展

介绍城市轨道交通车辆选型的历史与发展，车辆选型其国产化进程及采取的策略。     

城轨车辆电气调试常见故障问题分析及应对策略

为了保证城轨车辆安全运行,首先介绍我国城市轨道交通车辆的电气系统故障的成因,并对其故障类型进行分析,并提出相应的应对城轨车辆电气调试故障对策,以期为同类型工作提供参考。     

城市轨道交通车辆日检维护策略探究

在保证城市轨道交通车辆可靠维修质量前提下,为了进一步实现降低成本、提高效率,本文基于可靠性理论,期以通过对上海地铁某线路各系统部件进行可靠性分析,从影响部件潜在失效的措施优先级角度入手,对设备风险、运营影响等方面等级进行再次定义,并在此基础上,以该分析基础对日检手册各项点进行全面地风险分析,从而最终确定各检查项点的风险等级,根据风险等级确定城市轨道车辆运行状态和潜在风险,评估并优化城市轨道车辆日检维护策略,期以实践后表明该方法的可行性,为今后城市轨道车辆日检维修策略的制定及优化提供参考.     

城市轨道交通工程设计中车辆选型的研究

以深圳地铁3号线为例,阐述在城市轨道交通工程设计中车辆的选型,以及如何确定轨道交通制式、车辆最高运行速度、车辆编组、车辆动拖比、车辆受流方式、制动电阻设置等主要技术原则。     

中低速磁浮交通应急响应预案研究

中低速磁浮列车作为全新的城市轨道交通制式,诸多优点契合了城市发展需要,不过,在中低速磁浮列车由试验线走向商业运营的过程中,紧急疏散和应急救援系统还没有形成一套完整的体系。文章通过对国内外城市轨道交通系统事故应急预案进行调研,针对国内中低速磁浮列车日常运营中的动力丢失故障、悬浮功能故障、车辆电气设备故障及车辆冲突故障等问题,同时结合地铁、跨座式单轨交通在车辆故障情况下的紧急疏散和应急救援模式,开展乘客的紧急疏散和应急救援以及车辆自身的应急救援方案研究,提出了相应的较为通用的应急响应预案。     

上海市若干轨道交通线车辆基地选址特点

讨论城市轨道交通车辆基地场址选择问题,通过上海市轨道交通4号线、2号线、8号线、6号线车辆基地场址的选择过程及特点介绍,总结车辆基地场址选择过程中应注意的事项,为其他轨道交通线路车辆基地的选择提供参考。     

城市轨道交通供电系统安全管理及设备维护措施分析

城市轨道交通供电系统是保障城市轨道交通安全、高效运行的关键。为了确保供电系统的安全性和可靠性,对城市轨道交通供电系统进行介绍,并对城市轨道交通供电系统安全管理及设备维护措施进行分析,以期为相关工作人员提供参考。     

城市轨道交通列车晚点成因分析及对策

为了解决城市轨道交通列车晚点问题,城市轨道交通列车晚点成因分析,对城市轨道交通行车调整方式进行探究,提出城市轨道交通列车晚点的控制对策以供参考。     

Life cycle emissions and cost model for urban light duty vehicles

The growth of vehicle sales and use internationally requires the consumption of significant quantities of energy and materials, and contributes to the deterioration of air-quality and climate conditions. Advanced propulsion systems and electric drive vehicles have substantially different characteristics and impacts. They require life cycle assessments and detailed comparisons with gasoline powered vehicles which, in turn, should lead to critical updates of traditional models and assumptions. For a comprehensive comparison of advanced and traditional light duty vehicles, a model is developed that integrates external costs, including emissions and time losses, with societal and consumer life cycle costs. Life cycle emissions and time losses are converted into costs for seven urban light duty vehicles. The results, which are based on vehicle technology characteristics and transportation impacts on environment, facilitate vehicle comparisons and support policy making in transportation. Substantially, more sustainable urban transportation can be achieved in the short-term by promoting policies that increase vehicle occupancy; in the intermediate-term by increasing the share of hybrid vehicles in the car market and in the long-term by the widespread use of electric vehicles. A sensitivity-analysis of life cost results revealed that vehicle costs change significantly for different geographical areas depending on vehicle taxation, pricing of gasoline, electric power and pollution. Current practices in carbon and air quality pricing favor oil and coal based technologies. However, increasing the cost of electricity from coal and other fossil fuels would increase the variable cost for electric vehicles, and tend to favor the variable cost of hybrid vehicles.     

Consumer preferences for alternative fuel vehicles: A discrete choice analysis

This paper analyzes the potential demand for privately used alternative fuel vehicles using German stated preference discrete choice data. By applying a mixed logit model, we find that the most sensitive group for the adoption of alternative fuel vehicles embraces younger, well-educated, and environmentally aware car buyers, who have the possibility to plug-in their car at home, and undertake numerous urban trips. Moreover, many households are willing to pay considerable amounts for greater fuel economy and emission reduction, improved driving range and charging infrastructure, as well as for enjoying vehicle tax exemptions and free parking or bus lane access. The scenario results suggest that conventional vehicles will maintain their dominance in the market. Finally, an increase in the battery electric vehicles’ range to a level comparable with all other vehicles has the same impact as a multiple measures policy intervention package.     

Electric vehicles in car sharing networks – Challenges and simulation model analysis

In this paper, we examine the operation of electric vehicles in urban car sharing networks. After surveying strategic and operational differences and comparing them to gasoline-fueled cars, a simulation study was carried out. The proposed discrete event simulation tool covered important operational characteristics of electric vehicles, including realistic charging routines. Different vehicle types were compared under various conditions and on multiple markets to determine their performance. The data obtained indicated the competitiveness of electric vehicles in car sharing networks. Key success factors included advantageous relations between the market environment (e.g. electricity and fuel prices) and important characteristics of electric cars (e.g. price and range).     

Empirics of multi-modal traffic networks – Using the 3D macroscopic fundamental diagram

Traffic is multi-modal in most cities. However, the impacts of different transport modes on traffic performance and on each other are unclear – especially at the network level. The recent extension of the macroscopic fundamental diagram (MFD) into the 3D-MFD offers a novel framework to address this gap at the urban scale. The 3D-MFD relates the network accumulation of cars and public transport vehicles to the network travel production, for either vehicles or passengers. No empirical 3D-MFD has been reported so far.In this paper, we present the first empirical estimate of a 3D-MFD at the urban scale. To this end, we use data from loop detectors and automatic vehicle location devices (AVL) of the public transport vehicles in the city of Zurich, Switzerland. We compare two different areas within the city, that differ in their topology and share of dedicated lanes for public transport. We propose a statistical model of the 3D-MFD, which estimates the effects of the vehicle accumulation on car and public transport speeds under multi-modal traffic conditions. The results quantify the effects of both, vehicles and passengers, and confirm that a greater share of dedicated lanes reduces the marginal effects of public transport vehicles on car speeds. Lastly, we derive a new application of the 3D-MFD by identifying the share of public transport users that maximizes the journey speeds in an urban network accounting for all motorized transport modes.     

Lane-harmonised passenger car equivalents for heterogeneous expressway traffic

In order to account for variations in traffic composition during traffic analysis, passenger car equivalent (PCE) factors are used to convert flow rates of various vehicle classes into flow rates in terms of passenger car units (PCUs). Earlier studies have developed various methods to estimate PCE values but only a few of them are based on uninterrupted traffic flow, particularly for flow regimes with heterogeneous traffic where differential (lower) speed limits are imposed on commercial vehicles. This paper proposes a lane-harmonisation approach, which leverages on the high variation in traffic composition across the lanes, to estimate PCE factors for urban expressways. Multiple linear regression is used and the PCE factors obtained for motorcycles, light goods vehicles, and heavy goods vehicles are 0.65, 1.53, and 2.75, respectively. The estimated capacity flow rate after the application of the obtained PCE factors is around 2200 PCUs per hour per lane.     

Car ownership and access to jobs in Spain

The purpose of this paper is to assess the effect of urban structure on household car ownership in a context of rapid job and population decentralization. We capture the effect of urban structure through a measure of job accessibility to employment by public transport. An ordered probit explaining the number of cars per household is estimated as a function of individual, household and spatial variables. The data used in the analysis come from the Spanish Institute of Statistics’ 2001 Micro-census for the areas of Barcelona and Madrid. The results show that spatial variables play a significant role in explaining the probability of car ownership. We provide the car ownership elasticities with respect the job accessibility measure. Additionally, we carried out simulation exercises in which the expected number of vehicles decreases as accessibility improves.     

Solving the User Optimum Privately Owned Automated Vehicles Assignment Problem (UO-POAVAP): A model to explore the impacts of self-driving vehicles on urban mobility

Interest in vehicle automation has been growing in recent years, especially with the very visible Google car project. Although full automation is not yet a reality there has been significant research on the impacts of self-driving vehicles on traffic flows, mainly on interurban roads. However, little attention has been given to what could happen to urban mobility when all vehicles are automated. In this paper we propose a new method to study how replacing privately owned conventional vehicles with automated ones affects traffic delays and parking demand in a city. The model solves what we designate as the User Optimum Privately Owned Automated Vehicles Assignment Problem (UO-POAVAP), which dynamically assigns family trips in their automated vehicles in an urban road network from a user equilibrium perspective where, in equilibrium, households with similar trips should have similar transport costs. Automation allows a vehicle to travel without passengers to satisfy multiple household trips and, if needed, to park itself in any of the network nodes to benefit from lower parking charges. Nonetheless, the empty trips can also represent added congestion in the network. The model was applied to a case study based on the city of Delft, the Netherlands. Several experiments were done, comparing scenarios where parking policies and value of travel time (VTT) are changed. The model shows good equilibrium convergence with a small difference between the general costs of traveling for similar families. We were able to conclude that vehicle automation reduces generalized transport costs, satisfies more trips by car and is associated with increased traffic congestion because empty vehicles have to be relocated. It is possible for a city to charge for all street parking and create free central parking lots that will keep total transport costs the same, or reduce them. However, this will add to congestion as traffic competes to access those central nodes. In a scenario where a lower VTT is experienced by the travelers, because of the added comfort of vehicle automation, the car mode share increases. Nevertheless this may help to reduce traffic congestion because some vehicles will reroute to satisfy trips which previously were not cost efficient to be done by car. Placing the free parking in the outskirts is less attractive due to the extra kilometers but with a lower VTT the same private vehicle demand would be attended with the advantage of freeing space in the city center.     

Electric versus conventional vehicles: social costs and benefits in France

This article compares the social costs of electric vehicles with those of conventional, thermal vehicles for typical passenger use in the Ile-de-France region (Greater Paris), a case of particular interest because nearly 80% of the electricity is generated by nuclear power plants. A four-seat electric car is compared to a new conventional car of the same make and model; for the latter both the gasoline and the diesel version are considered because almost half of new car sales in France are diesel. These results are also compared to typical existing diesel and gasoline vehicles in the current French fleet. The methodology developed by the ExternE (External Costs of Energy) Project of the European Commission is used to estimate the costs associated with atmospheric pollution due to power plants, refineries and tail pipe emissions. Our discussion of externalities is limited to air pollution thus excluding others such as costs associated with noise or accidents. Our results imply that the external costs are large and significant, even when one considers the uncertainties. If internalized by government regulations, these externalities can render the total cost of an electric vehicle more competitive with that of currently available thermal vehicles in large urban centers if the electricity is produced by sources with low pollution. However, the current generation electric vehicles are so expensive that internalization of pollution damage would not give it a very clear advantage.     

Modelling heavy vehicle car‐following behaviour in congested traffic conditions

This study develops a car‐following model in which heavy vehicle behaviour is predicted separately from passenger car. Heavy vehicles have different characteristics and manoeuvrability compared with passenger cars. These differences could create problems in freeway operations and safety under congested traffic conditions (level of service E and F) particularly when there is high proportion of heavy vehicles. With increasing numbers of heavy vehicles in the traffic stream, model estimates of the traffic flow could be degrades because existing car‐following models do not differentiate between these vehicles and passenger cars. This study highlighted some of the differences in car‐following behaviour of heavy vehicle and passenger drivers and developed a model considering heavy vehicles. In this model, the local linear model tree approach was used to incorporate human perceptual imperfections into a car‐following model. Three different real world data sets from a stretch of freeway in USA were used in this study. Two of them were used for the training and testing of the model, and one of them was used for evaluation purpose. The performance of the model was compared with a number of existing car‐following models. The results showed that the model, which considers the heavy vehicle type, could predict car‐following behaviour of drivers better than the existing models. Copyright © 2013 John Wiley & Sons, Ltd.     

Including heavy vehicles in a car‐following model: modelling,calibrating and validating

Heavy vehicles influence general traffic in many different ways compared with passenger vehicles, and this may result in different levels of traffic instability. Increases in the number and proportion of heavy vehicles in the traffic stream will therefore result in different traffic flow conditions. This research initially outlines the different car‐following behaviour of drivers in congested heterogeneous traffic conditions indicating the necessity for developing a car‐following model, which includes these differences. A psychophysical car‐following model, similar in form to Weideman's car‐following model, was developed. Due to the complexity of the developed model, the calibration of the model was undertaken using a particle swarm optimisation algorithm with the data recorded under congested traffic conditions. This was then incorporated into a traffic microsimulation model. The results showed that the car‐following perceptual thresholds and thus action points of drivers differ based on their vehicle and the lead vehicle types. The inclusion of the heavy vehicles in the model showed significant impacts on the traffic dynamic and interactions amongst different vehicles. Copyright © 2016 John Wiley & Sons, Ltd.