基于DSRC和CDPD的先进公交系统

本文首先讲述了ITS中的2种通信技术——专用短程通信（DSRC）和蜂窝数字分组数据网（CDPD）的基本概念、工作原理及系统特点等，然后提出了一种基本这2种通信技术的先进公交系统，并对各个子系统的功能结构进行了描述。     

基于网格技术的城市公共汽车到站时刻预测研究

在介绍了网格技术的含义和基础知识后,结合我国目前公共汽车预测研究的现状,设计了基于网格技术的城市公共汽车到站时间的预测系统,并对其进行了详细的设计。     

ROFIBUS现场总线在彩涂板生产线中的研究与实践

现今,我国的彩色涂层钢板的生产已经有了一定的发展,但是其生产水平还是比较低下,不能满足现代社会产业发展理念的需求,不能满足低碳发展、可持续发展的价值理念,PROFIBUS现场总线技术在生产中极大地满足了企业对彩涂板生产的需求。     

Electrification of a city bus network—An optimization model for cost-effective placing of charging infrastructure and battery sizing of fast-charging electric bus systems

The deployment of battery-powered electric bus systems within the public transportation sector plays an important role in increasing energy efficiency and abating emissions. Rising attention is given to bus systems using fast charging technology. This concept requires a comprehensive infrastructure to equip bus routes with charging stations. The combination of charging infrastructure and bus batteries needs a reliable energy supply to maintain a stable bus operation even under demanding conditions. An efficient layout of the charging infrastructure and an appropriate dimensioning of battery capacity are crucial to minimize the total cost of ownership and to enable an energetically feasible bus operation. In this work, the central issue of jointly optimizing the charging infrastructure and battery capacity is described by a capacitated set covering problem. A mixed-integer linear optimization model is developed to determine the minimum number and location of required charging stations for a bus network as well as the adequate battery capacity for each bus line. The bus energy consumption for each route segment is determined based on individual route, bus type, traffic, and other information. Different scenarios are examined in order to assess the influence of charging power, climate, and changing operating conditions. The findings reveal significant differences in terms of required infrastructure. Moreover, the results highlight a trade-off between battery capacity and charging infrastructure under different operational and infrastructure conditions. This paper addresses upcoming challenges for transport authorities during the electrification process of the bus fleets and sharpens the focus on infrastructural issues related to the fast charging concept.     

Impact of bus rapid transit on housing price and accessibility changes in Sydney: A repeat sales approach

ABSTRACT

New public transport infrastructure is expected to improve accessibility for local residents, and thus contribute to increased land value. The contribution that a bus rapid transit (BRT) system can make to increased land value is less certain than for rail-based systems, with the literature mostly containing bus-based examples from developing countries with extensive BRT networks. This article considers a BRT system named the Liverpool–Parramatta Transitway (LPT) that was implemented in southwestern Sydney in 2003 to improve public transport accessibility in the local area. A repeat sales model is constructed to investigate the impact of the LPT on residential housing prices and accessibility changes using repeat sales data from before and after the opening of the LPT. This identified little price difference between properties close to LPT stations and outside of the area that could be considered as affected by the LPT service coverage. This outcome is at variance with the theoretical underpinning of land value uplift and other empirical evidence relating to the LPT. Hedonic models using the same repeat sales data investigate the study area in more detail, stratifying the sample by housing type and by comparing separate before and after models. These research outcomes identify the extent to which the BRT system has an impact on local housing prices through accessibility improvements to the study area and provide a deeper understanding as to how the quantification of land value uplift from BRT represents one element of the wider economic benefits of a BRT system.     

浅谈公交优先对城市综合发展的作用

随着城市规模的扩大和城市人口的增加,城市交通的压力也正在不断加剧,公交优先的方向应当始终坚持。实行公交优惠票价政策,体现了社会资源共享的公平性和经济合理性,有助于缓解交通拥堵,减轻大气污染保护环境,也有助于建立和谐社会,促进城市繁荣和城市综合发展。     

基于成本分析的发车频率模型在广州BRT的应用

班车的发车频率对服务水平及成本控制都起着重要作用。发车频率低,可以降低成本,但是不能满足乘客需求,会引发一系列社会问题;发车频率高,虽然给乘客提供了更好的服务,但是却大大增加了运营成本。本文将在陈文进《大众运输路线服务模式构建之研究》中提出的基于成本的公交班车派发频率模型的基础上,增加环境因素的考虑对模型进行完善。再次本文将以LINGO为工具对模型进行简单求解,并将模型应用于广州快速公交对广州BRT的发车频率进行优化。     

电动轮自卸车电传动系统试验平台的可行性研究

文章依托科技部＂十五＂科研项目——＂交流驱动百吨级矿用自卸车的研制＂,介绍了电动轮自卸车的发展、原理和技术特点。为了满足电传动系统的试验需求,特别是对由柴油发动机、发电机、驱动电机及其测试和控制系统等构成的动力总成进行试验,建立了一个拥有不同驱动电机试验功能的试验平台。平台由变频异步电动机、交流同步发电机、驱动电机、测功机等机械设备和整流器、逆变器、励磁器等电气设备组成,采用CAN总线串行通信协议实现各电控单元之间的信息交换。通过发电机空载特性、外特性、驱动电机稳态运行性能等试验证明,该平台基本满足电动轮自卸车的各种试验条件,为驱动性能研究提供了良好的实验环境。     

基于USB总线的航向姿态系统角度测量仪设计

本文简要介绍了基于USB总线的航向姿态系统角度测量仪的设计原理,并详细描述了其软件和硬件的组成结构。     

微电子机械系统ADXL345的应用研究

微电子机械系统因其成本低、可靠性高、功耗低、体积小和重量轻等特点,在便携式电子设备中应用广泛。文章通过S3C2440针对美国ADI公司最新推出的三轴数字加速度计ADXL345进行运动特性的检测研究,为该器件的应用开发提供了一种方法。