Dispatching and coordination in multi-area railway traffic management

This paper deals with the development of decision support systems for traffic management of large and busy railway networks in case of severe disturbances. Railway operators typically structure the control of complicated networks into the coordinated control of several local dispatching areas. A dispatcher takes rescheduling decisions on the trains running on its local area while a coordinator addresses global issues that may arise between areas. While several advanced train dispatching models and algorithms have been proposed to support the dispatchers' task, the coordination problem did not receive much attention in the literature on train scheduling. This paper presents new heuristic algorithms for both local dispatching and coordination and compares centralized and distributed procedures to support the task of dispatchers and coordinators. We adopt dispatching procedures driven by optimization algorithms and based on local or global information and decisions. Computational experiments on a Dutch railway network, actually controlled by ten dispatchers, assess the performance of the centralized and distributed procedures. Various traffic disturbances, including entrance delays and blocked tracks, are analyzed on various time horizons of traffic prediction. Results show that the new heuristics clearly improve the global performance of the network with respect to the state of the art.     

Application of a human error framework to conduct train accident/incident investigations

Accident/incident investigations are an important qualitative approach to understanding and managing transportation safety. To better understand potential safety implications of recently introduced remote control locomotive (RCL) operations in railroad yard switching, researchers investigated six railroad accidents/incidents. To conduct the investigations, researchers first modified the human factors analysis and classification system (HFACS) to optimize its applicability to the railroad industry (HFACS-RR) and then developed accident/incident data collection and analysis tools based on HFACS-RR. A total of 36 probable contributing factors were identified among the six accidents/incidents investigated. Each accident/incident was associated with multiple contributing factors, and, for each accident/incident, active failures and latent conditions were identified. The application of HFACS-RR and a theoretically driven approach to investigating accidents/incidents involving human error ensured that all levels of the system were considered during data collection and analysis phases of the investigation and that investigations were systematic and thorough. Future work is underway to develop a handheld software tool that incorporates these data collection and analysis tools.     

基于SPN的CTCS-3级列控系统RBC切换建模与分析

在CTCS-3级列控系统中,RBC切换是车载设备的关键功能之一,它严重影响着列车的行车效率。本文采用随机Petri网层次化建模思想,对基于一部车载电台RBC切换方式进行建模和分析。建立了GSM—R故障模型为最底层模型,之后建立了周期性消息模型和非周期性消息模型,在此之上建立了RBC切换模型。最后,利用建模仿真软件TimeNET进行了仿真实验,以基于一部车载电台的RBC切换为例进行了分析,得到在不同列车运行速度和不同消息重发时间间隔对RBC切换成功率和切换时间的影响。     

汽车发动机配气机构仿真分析

虚拟样机技术是当前设计制造领域的一项新技术.它利用软件机械系统的三维实体模型和力学模型,分析和评估系统的性能,从而为物理样机的设计和制造提供依据.本文使用机械系统动力学仿真软件ADAMS,以D6114B高速柴油机的配气机构为例,建立和测试了该机构的虚拟样机,对下置凸轮轴高速发动机配气机构的性能进行了分析、预测.     

基于PLC模糊控制的列车制动软管试验台的设计与应用

根据列车制动软管试验台手动加载不稳定的情况,利用步进电机把手动加载阀改造成数字阀,采用模糊控制与PLC相结合的方式,设计试验台自动控制系统.实际应用结果表明:该控制系统具有稳定可靠、控制精确的特点.     

基于网络的火车售票系统

基于网络的火车售票系统是通过网络查询信息,进行火车票的预定、购买、支付的信息管理系统.订票在本系统中扮演着十分重要的角色,设计和实现一个完整的基于网络的基于网络的火车售票系统能够为旅客提供一个快捷、便利的购票渠道,对促进火车票务事业的发展具有十分重要的意义.本系统采用模块化程序设计方法,既便于系统功能的各种组合和修改,又便于未参与开发的技术维护人员补充、维护.本系统主要包括管理员管理模块、业务收费班次票单管理模块、用户注册模块、票单订购模块.最终实现了管理员对车次的添加、删除、修改,客户进行网上查询、订票、退票等功能.     

基于控制器iW2202的数字开关电源原理与设计

数字开关电源控制器iW2202利用被称做Pulse TrainTM的专有数字控制技术和升压变换器与隔离回扫变换器相结合的BIFRED拓扑,获得超过85%的效率和接近1的功率因数。主要介绍了iW2202的主要特点、工作原理和基于iW2202的70 W膝上电脑电源设计。     

高职物流管理专业培养目标和课程设置问题的探讨

分析了高职物流管理教育在物流教育体系中的地位,指出高职开设物流管理专业是完善多层次教育体系,满足对物流人才多样化需求的行为.根据高职物流管理专业培养目标的层次和类型、就业岗位群及物流行业对学生知识能力的要求,提出了高职物流管理专业培养目标及课程结构体系设置的初步意见.     

Autonomous decentralized control and its application to the rapid transit system

A large scale control system has three intrinsic requirements of fault tolerance, on-line extension and maintenance for non-stop operation. For attaining these requirements, the new design philosophy for autonomous decentralized control system, called HAL (Harmonous, Autonomous and Localities) concept, has been proposed based on the biological analogy.The viewpoint of this concept is that it is quite normal for a system to have failed parts.Sufficient conditions for an autonomous decentralized control system are given that every subsystem is uniform and equal in function and structure, and utilizes only local information for control and coordination.As one of the applications to the system components of this new concept, ADL-Net (Autonomous Decentralized Loop Network) has been developed, where fault tolerance of the system is attained by giving autonomy for fault detection, recovery and transmission to every network control processor.The HAL concept has also been applied to the train traffic control system for subways with three intrinsic requirements for supporting their non-stop operations.     

列车无接触制动的探讨

传统的踏板制动存在的问题是制约提高运力的主要矛盾，是限制列车运行速度和扩大编组的主要障碍。本文提出了无接触式的涡流制动的结构原理和简单的控制方法，这项新技术是提高运力的主要措施。