基于CAN总线数据的LNG公交车能源 消耗分析

为研究公交车辆在正常运营中能源消耗的影响因素,通过CAN总线数据与公交IC 卡数据 的融合,从站点间断面以及站点两个层面对北京市液化天然气（LNG） 公交车辆的能源消耗影响 因素进行了相关分析。首先分析了不同道路等级下的能耗消耗,然后利用SPSS 的相关性分析工 具对能耗的影响因素进行了分析。通过分析发现,公交车辆在公交专用道路段的行驶速度约为非 公交专用道的1.7 倍,能源消耗约为无公交专用道的70%。能源消耗由高到低依次为辅路、匝 道、主干路。同时在站点层面,车辆的能源消耗主要受到停滞时间、车辆的加减速时间、乘客的 上下车人数的影响。期望通过此项研究能够帮助公共交通的运营和规划部门制定相应的政策,以 达到减少能源消耗的同时提高公共交通运行效率的目的。     

终止站停命令的缺陷及解决方法

广州地铁1号线正线信号设备由德国西门子公司引进,在使用过程中系统存在一定的缺陷.为保证行车安全,在分析该信号系统原理的基础上,结合用户经验,重点对系统中"终止站停"操作指令的原理及缺陷进行研究,提出相应的解决方法.     

车载总线通讯安全分析

随着汽车智能化和网联化的快速发展,车辆上应用的电子控制单元（ECU）数量越发庞大。在成本有效控制的基础上保证不同种类的电子控制单元可以有效地通讯,不同的总线协议被应用到车辆上。车辆作为对于安全性要求非常高的一种产品,不同的总线协议有着其独有的特点。对不同总线应用过程可能出现的安全性问题进行分析,是保证车辆安全开发的必要的条件。文章对不同的车载总线应用情况进行简要介绍,明确常见总线类型的各自特点,归纳不同协议类型的总线在应用过程中的面临的共性问题,分析风险问题的产生,可能风险点并提出简要防护措施。     

Adaptive control algorithm to provide bus priority with a pre-signal

In urban areas, where road space is limited, it is important to provide efficient public and private transportation systems to maximize person throughput, for example from a signalized intersection. To this end, this research looks at providing bus priority using a dedicated bus lane which is terminated upstream of the intersection, and placing an additional signal at this location, called a pre-signal. Although pre-signals are already implemented in some countries (e.g. UK, Denmark, and Switzerland), an adaptive control algorithm which responds to varying traffic demands has not yet been proposed and analyzed in the literature. This research aims to fill that gap by developing an adaptive control algorithm for pre-signals tailored to real-time private and public transportation demands. The necessary infrastructure to operate an adaptive pre-signal is established, and guidelines for implementation are provided. The relevant parameters regarding the boundary conditions for the adaptive algorithm are first determined, and then quantified for a typical case using a micro-simulation model. It is demonstrated with case studies that, under all considered scenarios, implementing a pre-signal with the proposed adaptive control algorithm will result in the least average person delay at the intersection. The algorithm is expected to function well with a wide range of car demands, bus frequencies, and bus passenger occupancies. Moreover, the algorithm is robust to errors in these input values, so exact information is not required.     

Bus arrival time calculation model based on smart card data

Bus arrival time is usually estimated using the boarding time of the first passenger at each station. However, boarding time data are not recorded in certain double-ticket smart card systems. As many passengers usually swipe the card much before their alighting, the first or the average alighting time cannot represent the actual bus arrival time, either. This lack of data creates difficulties in correcting bus arrival times. This paper focused on developing a model to calculate bus arrival time that combined the alighting swiping time from smart card data with the actual bus arrival time by the manual survey data. The model was built on the basis of the frequency distribution and the regression analysis. The swiping time distribution, the occupancy and the seating capacity were considered as the key factors in creating a method to calculate bus arrival times. With 1011 groups of smart card data and 360 corresponding records from a manual survey of bus arrival times, the research data were divided into two parts stochastically, a training set and a test set. The training set was used for the parameter determination, and the test set was used to verify the model’s precision. Furthermore, the regularity of the time differences between the bus arrival times and the card swiping times was analyzed using the “trend line” of the last swiping time distribution. Results from the test set achieved mean and standard error rate deviations of 0.6% and 3.8%, respectively. The proposed model established in this study can improve bus arrival time calculations and potentially support state prediction and service level evaluations for bus operations.     

Is rail cleaner and greener than bus?

The popular consensus is that urban passenger rail is more environmentally friendly than urban passenger bus. This position is largely associated with the key energy source for each mode, respectively electricity and diesel, where electric vehicle use will typically result in local air quality improvements away from the electricity generation source. Surveys of community perceptions reflect this sentiment; however the relationship between the source of energy and its resultant emissions is not something that citizens fully understand. There is a general lack of awareness of the resource base of much of electricity generation in some countries. Where generation sources are suitably renewable or low-carbon, electricity use will offer greenhouse gas abatement potential. However, in countries which still rely heavily on coal-fired power stations, such as Australia, abatement is not as assured and estimating emission outcomes can require careful assessment. Supporters of alternatives to diesel use can focus on the future supply of fossil-fuels, an argument which has merit; however such arguments are often confounded with environmental qualities related to local air pollution and enhanced greenhouse gas emissions. This paper takes a close look at the greenhouse emissions that are associated with urban rail and bus in Australia. Estimated intensities, when presented in the context of effective service delivery (primarily in terms of emissions per passenger kilometre), raise questions about the distortions that are present in the widespread promotion in Australia (at least) of rail as a more environmentally friendly and hence a sustainable mode of urban passenger transport than bus.     

城市主干道快速公交(BRT)系统合理站距规划布局

快速公交系统充分利用道路资源,形成大容量、快捷、舒适的公交服务体系,将是承担我国大中城市出行交通的主体,是解决当前大中城市交通问题的重要途径。论文在研究城市主干道交通流行驶特性的基础上,结合城市道路网及交通特性分析、城市主干道快速公交(BRT)系统的交通功能及主干道沿线用地特征分析,提出了城市主干道快速公交(BRT)系统规划布局的合理站距。     

城市公交专用道系统规划方法探讨——以深圳为例

针对大城市日趋复杂的公交系统，提出了公交专用道系统规划的方法，完善公交专用道的功能分类，明确各类公交专用道的主要服务对象和交通特性，并提出相应的设施要求。最后，以深圳公交专用道系统规划初步方案为例，按上述理论方法进行了实证说明。     

哥本哈根TOD模式研究

在长远规划的指导下,哥本哈根利用公交引导城市发展的模式(TOD)构建了“手形”的城市形态和可持续的交通系统,放射形的轨道交通线网对引导城市有序扩张起到了决定性作用。以哥本哈根城市发展经验为例,结合国内城市的发展状况,提出了中国城市应该大力推广TOD模式,并特别提出了以快速公交系统引导城市发展的新理念。