Sensitivity of train stochastic dynamics to long-term evolution of track irregularities

The influence of the track geometry on the dynamic response of the train is of great concern for the railway companies, because they have to guarantee the safety of the train passengers in ensuring the stability of the train. In this paper, the long-term evolution of the dynamic response of the train on a stretch of the railway track is studied with respect to the long-term evolution of the track geometry. The characterisation of the long-term evolution of the train response allows the railway companies to start off maintenance operations of the track at the best moment. The study is performed using measurements of the track geometry, which are carried out very regularly by a measuring train. A stochastic model of the studied stretch of track is created in order to take into account the measurement uncertainties in the track geometry. The dynamic response of the train is simulated with a multibody software. A noise is added in output of the simulation to consider the uncertainties in the computational model of the train dynamics. Indicators on the dynamic response of the train are defined, allowing to visualize the long-term evolution of the stability and the comfort of the train, when the track geometry deteriorates.     

基于C#的TCU自动测试工具设计研究

文章介绍了一种自主设计开发的TCU自动测试工具。主要介绍了基于C#的上位机软件的设计开发,包括页面、类库、测试项目和变量信息的设计编程,Kvaser CAN通讯库的使用,XCP协议的实现,A2L文件解读,Excel报告生成等。另外还介绍了CAN-extender的硬件接口和软件脚本开发,测试负载箱电路原理和改装方法。通过以上项目的研究工作,可以设计出一种自动测试TCU的试验台,大大提高量产TCU测试验收的工作效率。     

船舶舯剖面的可靠性优化设计

本文利用正交试验设计理论,借助改进型的一阶二次矩方法(AFOSM),把规范对船舶的总纵强度要求转化为相应的最小安全指数βmin, 然后建立可靠性优化的数学模型,由混合整数规划方法求解.某散货船算例表明:本文方法实用而可行,具有一定的经济效益.     

基于动态规划的舰船最佳航路设计

针对目前对舰船最佳航路选择的重要性，通过分析明确了舰船最佳航路的概念，并用发展和应用比较成熟的动态规划方法对舰船最佳航路的设计进行建模，以期得到实际应用。     

TKCAD软件系统的运行管理

TKCAD 是在微机上开发的铁道客车计算机辅助设计软件系统,该系统要求多环境支持,并具有复杂的运行流程方式.本文实现了该软件系统的运行管理体制,并提出了内存中不留任何残余碎块的汉字操作系统的动态撤离技术.     

公路工程中混凝土配制最小费用的简单计算

应用优化原理,利用Excel软件辅助设计,解决了公路工程中混凝土配制的优化问题。     

收敛系统的性质

离散时间收敛系统是研究离散时间线性模型渐近理论的重要工具。利用随机积分工具推广了离散时间收敛系统的概念,给出收敛系统的定义并获得了收敛系统的几个重要性质。     

地铁联络线建设成本优化法的0-1规划模型

地铁联络线合理布局既是城市轨道交通线网规划的重要组成部分,又是提高线路通过能力的必要保证。通过对联络线的重要性以及建设成本优化法的基本思路和寻优过程进行分析,找出了该方法的不足,建立0-1规划模型,并用lingo编程实现最优化;最后得到一般情况下该问题的数学模型。     

Line haul interstation spacing for low cost feeder modes

The choice behaviour of low cost travel (LCT) modes is very sensitive to travel distance. A line haul system designed on the basis of current planning practice of locating widely spaced stations to cater auto and bus feeder modes with the primary objective of gaining travel speed is hostile to non‐motorized and low cost feeder modes. With the revival of interest in promoting the use of walk'n ride and bike'n ride modes, there is a need to develop an appropriate tool to examine the effect of their specific characteristics in establishing the number and location of stations.

A generic normative behavioural hybrid model for locating the cost minimizing number and location of stations is developed for an LCT‐fed line haul system. The model considers the system with many to many two dimensional line haul demand density function in which the density varies in both x‐ and y‐directions. The feeder mode choice behaviour is incorporated in the model by integrating probability‐access/egress distance function with the objective function. Explicit functional relationships among the parameters of these feeder modes such as modal share as a function of access/egress distance with the parameters of line haul systems are developed. Dynamic programming is used to minimize the system cost. The generic model is shown to collapse into several simplified models capable of yielding approximate solutions for several well known special cases. It has been shown that location of stations is sensitive to the through load on board as well as users’ cost that defines the choice behaviour at large. Numerical examples are presented to demonstrate the applicability of the model.