城市轨道交通两线换乘形式及便捷性研究

通过研究城市轨道交通两线换乘车站站位关系、乘客换乘路径和站台型式组合三大要素,基于综合叠加后形成的换乘形式,对城市轨道交通两线换乘的便捷性进行分析。依据换乘距离计算结果,在不考虑客流分布特征等其他外部因素时,同站台换乘便捷性最高,垂直平行比水平平行便捷性更好;十字型、T型、L型换乘便捷性依次降低,在线路相交时应优先选择十字型;虚T型、虚L型和分离式换乘便捷性较低,主要取决于换乘通道长度。无论采用何种换乘形式,为便于统筹协调资源和提高运作效率,建议换乘车站实行一体化管理,在管理界面、设备设施两个维度做好切分。     

城市轨道交通车站内客流组织

简要地阐述了影响轨道交通换乘的两个主要问题,并就其中换乘站内客流的组织问题做了详细研究。在分析换乘站内客流特征的基础上,考虑乘客客流的构成和分布及影响协调组织客流的因素,提出优化站内客流组织的措施。     

公交网络最优路径求解算法

求解公交网络最优路径是进行公共交通系统规划的一项关键技术.通过对多种现有算法的分析,利用公交换乘矩阵性质,本文提出了一种求解公交网络最优路径的标准算法.新算法考虑了公交换乘次数、换乘点选择以及出行总成本对求解最优路径的综合影响.通过建立换乘步行时间矩阵,并将过去求解最小换乘次数的换乘矩阵乘法运算变为相应的换乘步行时间矩阵和公交出行时间矩阵的加法运算,得到新算法.新算法可顺利实现在单一OD对、单起点多终点以及任意节点间求解最优路径的转化.文中给出了新算法的详细求解步骤,而且通过一个算例对新算法的有效性进行了验证.     

换乘站火灾报警及监控系统设计方案

结合城市轨道交通工程中换乘车站相关各线路建设时序的不同，对换乘车站的类型进行划分，并从系统运行可靠性、系统投资经济性、运营管理便利性等方面，对换乘车站中的火灾自动报警系统、环境与设备监控系统、变电所综合自动化系统按线路分设和合设两种不同方案进行分析比较，从而得出不同类型的换乘车站中各系统的建议设置方案，即建设时序相隔较近时，宜采用合设的方案，而建设时序相隔较远时，宜采用分设的方案.     

A stochastic optimization model for transit network timetable design to mitigate the randomness of traveling time by adding slack time

Transit network timetabling aims at determining the departure time of each trip of all lines in order to facilitate passengers transferring either to or from a bus. In this paper, we consider a bus timetabling problem with stochastic travel times (BTP-STT). Slack time is added into timetable to mitigate the randomness in bus travel times. We then develop a stochastic integer programming model for the BTP-STT to minimize the total waiting time cost for three types of passengers (i.e., transferring passengers, boarding passengers and through passengers). The mathematical properties of the model are characterized. Due to its computational complexity, a genetic algorithm with local search (GALS) is designed to solve our proposed model (OPM). The numerical results based on a small bus network show that the timetable obtained from OPM reduces the total waiting time cost by an average of 9.5%, when it is tested in different scenarios. OPM is relatively effective if the ratio of the number of through passengers to the number of transferring passengers is not larger than a threshold (e.g., 10 in our case). In addition, we test different scale instances randomly generated in a practical setting to further verify the effectiveness of OPM and GALS. We also find that adding slack time into timetable greatly benefits transferring passengers by reducing the rate of transferring failure.     

Optimizing coordinated transfer with probabilistic vehicle arrivals and passengers' walking time

Supporting efficient connections by synchronizing vehicle arrival time and passengers' walking time at a transfer hub may significantly improve service quality, stimulate demand, and increase productivity. However, vehicle travel times and walking times in urban settings often varies spatially and temporally due to a variety of factors. Nevertheless, the reservation of slack time and/or the justification of vehicle arrival time at the hub may substantially increase the success of transfer coordination. To this end, this paper develops a model that considers probabilistic vehicle arrivals and passengers walking speeds so that the slack time and the scheduled bus arrival time can be optimized by minimizing the total system cost. A case study is conducted in which the developed model is applied to optimize the coordination of multiple bus routes connecting at a transfer station in Xi'an, China. The relationship between decision variables and model parameters, including the mean and the standard deviation of walking time, is explored. It was found that the joint impact of probabilistic vehicle arrivals and passengers' walking time significantly affects the efficiency of coordinated transfer. The established methodology can essentially be applied to any distribution of bus arrival and passenger walking time. Copyright © 2017 John Wiley & Sons, Ltd.     

减小电控罗经误差随纬度变化的方法研究

针对电控罗经误差随纬度变化而变化的弱点,从原理上分析了其重要原因,提出了两种可变修正回路传递系数方法,经仿真和实际应用证明,能大幅减小罗经在高纬度下的误差。     

基于光纤数字通信的直流双边联跳保护方案

介绍北京地铁亦庄线在国内轨道交通工程中首次应用的基于光纤数字通信的直流双边联跳保护方案.阐述方案的回路构成、联跳动作原理,分析方案设计过程中需要重点考虑的环节,并提出具体要求.与传统电缆传输信号的直流双边联跳方案进行综合经济技术比较,表明新方案具有良好的抗干扰性能、数据传输可靠性高,可以适用于任何工程环境.     

基于突变模型的轨道换乘效率评价

在城市轨道交通系统中,枢纽站的换乘效率直接影响到线网整体的运行效能。根据指标选取原则和换乘效率影响因素,选取换乘通畅性、舒适性、组织人数、有效性作为评价指标,在突变级数法的基础上,推导出突变理论的基本模型和分歧方程,确定突变模型。以重庆市轨道交通两路口站为例,结合换乘站乘客满意度调查结果,利用突变模型对换乘效率进行评价。验证模型的实用性和可操作性,并进一步提出提升换乘效率的改进措施。所建立的效率评价模型可以为轨道换乘站的运营、组织及管理提供决策支持。     

公共自行车动态调度系统需求预测模型研究

基于交通出行理论,将公共自行车需求分为直接需求和间接需求,并研究需求等待、转移和消退的变化规律.根据各租赁点的历史出行OD和以往时段的借、还车信息,预测出调度车辆从当前位置到达任意租赁点时该位置的车辆数,从而确定调度车数并制定调度计划,建立租赁点短期多时段的需求预测模型.将需求预测模型与调度计划模型组合成具有迭代反馈特性的双层模型,并通过计算机仿真方法求解,得到最优动态调度方案下的需求预测结果.通过算例对模型进行了验证,结果表明:公共自行车动态调度系统需求预测模型与调度计划模型结合后能有效改善公共自行车实际运营中借车时无车可借、还车时车位已满的情况.