基于UM的磁浮列车-轨道梁耦合振动仿真程序开发

基于大型通用多体动力学仿真分析平台Universal Mechanism(UM),开发用于磁浮列车 轨道梁耦合振动仿真的专用程序UM Maglev,其中：磁浮列车设置为多刚体模型,弹簧和阻尼器的刚度和阻尼视为线性或非线性力元;轨道梁设置为三维铁木辛柯梁模型,或从外部有限元软件导入模态分析结果;轨道线路包含平面和纵断面曲线、超高和轨面随机不平顺;悬浮和导向系统控制采用PID模型;多体动力学系统微分 代数方程求解采用Park刚性稳定法。该程序可用于考察磁浮列车的曲线通过性能、运行平稳性和乘坐舒适度,研究悬浮/导向气隙与磁浮控制系统参数优化,分析轨道梁在动态电磁力作用下的振动响应。     

横风下桥梁高度对高速列车交会性能的影响

为研究横风下桥梁高度对高速列车会车性能的影响,基于空气动力学和列车系统动力学,分析指数风分布下不同高度桥梁周围的流场,建立高速列车多体系统动力学模型,模拟横风下列车在不同高度桥梁上会车时的表面压力特性和气动载荷特性.将得到的气动力作为外加载荷作用于列车上,分析桥梁高度对高速列车会车安全性能的影响.结果表明:当列车在环境风下交会时,背风侧列车的气动力波动大于迎风侧列车的气动力波动;当监测点风速固定且桥梁高度小于15 m时,随着桥梁高度的增加,列车的气动载荷最大幅值和安全指标最大幅值均有所减小;当桥梁高度为15～30 m时,随着桥梁高度的增加,列车的气动性能和动力学性能基本保持不变.     

Impact in a railway truss bridge

The aim was to investigate the dynamic interactions between an open deck steel truss bridge and a moving freight train. A non-linear, 100-ton (gross weight 131.5 tons), freight car vehicle model and the 200-ft, open deck, Warren-type steel bridge model were used in this study. Equations of motion for the vehicle, bridge, and bridge/vehicle interactions were also presented. The track irregularities on the approach and the bridge were generated from power spectral density functions for Federal Railroad Administration (FRA) class 4 track (maximum speed 60 mph). Both zero and two percent of the critical damping were assumed for the bridge. Impact percentages in the bridge due to a three, 100-ton freight car train operating at 20, 40, and 60 mph were calculated. These were compared with the data obtained from an earlier field investigation and those specified by the American Railway Engineering Association (AREA) specifications.     

改进的元胞自动机列车交通流仿真模型研究

在既有元胞自动机模型的基础上,针对移动闭塞系统下列车追踪运行的特点提出一种改进的元胞自动机模型,该模型有效解决了既有模型中列车速度变化的不合理问题,提高了模型的准确性和可靠性。应用该模型获得了移动闭塞系统下列车流的相位图,并分析了移动闭塞系统中线路上快慢车开行比例及开行速差等因素对线路通过能力及列车平均速度的影响。研究结果表明,车站对列车流具有调和的作用,能够使列车流得到一定程度的同化。此外,减小快慢车速差可以有效增大线路的通过能力,而增加快车开行比例,则能够显著提高所有列车的运行效率,从而保证整个系统的高效运营。     

列车节能运行决策问题的模拟优化研究

轨道交通运输耗能巨大,研究列车节能操作运行具有重要的理论意义和实用价值。从节能角度出发,分析列车运行过程中的能量转换机制,建立单列车耗能最低优化模型、多列车节能优化模型及列车延误多目标优化控制模型,针对模型本身及其约束条件的复杂性,提出基于改进布谷鸟优化算法与动态搜索方法的“模拟优化”求解方法,对列车节能运行决策问题进行求解,并通过与其他同类算法的比较,阐述了所提方法的优越性。得到列车在不同运行工况下的最优节能运行控制策略,确定各情况下列车运行的最优速度距离曲线,结果符合实际情况。改进算法的搜索效率更高,研究思路与模型对于列车节能操作运行具有一定的借鉴意义,所提出的针对复杂优化模型的求解方法合理有效,适用性强,有一定的参考价值。     

Effects of speed, load and damping on the dynamic response of railway bridges and vehicles

In this paper, the effects of various parameters influencing the dynamic response of railway bridges are investigated. A versatile and computationally efficient numerical model was developed for this purpose. The model incorporates three-dimensional multi-body train and finite element bridge subsystems. The corresponding equations of motion are integrated numerically by applying the Newmark’s method combined with a modified Newton-Raphson iterative procedure. The model was verified by comparisons with analytical and numerical solutions available in the literature and good agreement was found. A parametric analysis was carried out to establish the key variables influencing the dynamic response of railway bridges. The speed of the train, train-to-bridge frequency, mass and span ratios, as well as bridge damping were identified as significant variables. Vehicle damping was found to have negligible influence on bridge response. Particularly strong dynamic amplification was found for train with shortly and regularly spaced axles travelling at the critical speeds. Other general conclusions were drawn on the basis of the parametric study.     

An optimal track maintenance scheduling model analysis taking the risk of accidents into consideration

This paper presents an optimal track maintenance scheduling model developed for maintaining adequate conditions of the railway tracks and accomplishing an efficient management of the railway service. Our model has been used in several major Japanese railway companies to develop optimal track maintenance schedules (OTMS). Since train accidents cause enormous losses (not only for the railway company but also for society), we propose to take into account the risk of train accidents while developing the OTMS. Thus, it is critically important to identify measures to quantitatively evaluate the risk of accidents to ensure safe and stable transportation. We propose a method to estimate track maintenance costs and the related costs associated with the risk of train derailment due to longitudinal level irregularities of the railway track. We attempt to show a desirable condition of railway tracks by applying the accident cost estimation method and the OTMS model to an actual railway section. We also demonstrate how to apply these models to actual railway networks in general by validating the estimation results using actual numerical data.     

基于混合逻辑动态的列车运行调度模型

通过对列车运行调度问题的分析,指出列车运行过程中存在正常事件、客观事件和主观事件三种类型事件,调度的本质是主观事件通过改变列车的运行速度来克服客观事件对列车造成的影响,是典型的混杂系统.在考虑车站股道约束和区间容量两个约束条件的基础上,采用混合逻辑动态理论建立了列车运行调度模型,仿真结果表明了模型的有效性.     

基于仿真数据的列车运动模型辨识

提出一种基于地铁列车的运行仿真数据来辨识列车传递函数的新思路。通过对列车运动模型的分析建立列车运行仿真中涉及到的多质点受力模型,用于计算不同车型混编的地铁列车的受力情况。以该受力模型为基础对列车的运行情况进行仿真实现,基于仿真软件生成的牵引力和速度随时间变化的数据,通过最小二乘法辨识出列车的传递函数。实验结果表明,辨识出的列车运动模型是有效的。     

直线轨道涡流制动对高速列车制动动力学特性的影响

列车制动性能直接影响车辆运行安全性和平稳性、稳定性,本文研究了加装直线轨道涡流制动系统对不同动力分配方式的高速列车制动动力学特性的影响规律.首先建立了6M2T和4M4T两种编组方式的列车动力学仿真模型,并与线路实验数据进行对比,验证了模型的有效性.基于该模型,研究了不同时速下的列车在不同动力分配形式下的动力学特性.针对惰行工况、电空制动工况与加装直线轨道涡流制动系统的联合制动工况,分别研究了第1、5、8节车厢的Sperling 指标、脱轨系数、轮重减载率、轮轨作用力的变化规律,研究结果表明,动力分配方式、制动特性对车辆动力学性能有显著影响,涉及的关键动力学性能指标均满足安全限值标准,研究结果将为高速列车加装直线轨道涡流制动系统提供理论参考.     

基于STeC的高速列车运行模型与算法

为了使高速列车正点运行到达目的车站,提出了基于STeC(时空一致性)语言的高速列车运行模型与算法。该模型具有位置触发自动调整高速列车运行的特点,实现动态确定高速列车制动点并保证列车正点到达目的车站,从而满足了高速列车运行实时系统对时间和空间的一致性要求。通过Matlab/Simulink的仿真测试,证明了该模型的正确性和有效性。     

Local energy minimization in optimal train control

The calculation of optimal driving strategies for on-board control of freight trains is a challenging task. In this paper we calculate the critical switching points for a globally optimal strategy on a track with steep gradients using a new local energy minimization principle. The method has been used successfully in Australia to calculate optimal switching points and hence provide in-cab advice to train drivers on long-haul freight trains.     

Advanced numerical analysis for vibration characteristics and ride comfort of ultra-high-speed maglev train

Magnetic levitation (maglev) trains are environmentally-friendly, require little maintenance, and allow for mass transportation. For these reasons, the demand for ultra-high-speed maglev trains has been increasing. Maglev trains can be classified with two suspension types, electro dynamic suspension (EDS) and electromagnetic suspension (EMS). EDS-type trains are suitable for ultra-high-speed because levitation suspension gap is over 100 mm compared with levitation suspension gap of 10 mm for EMS. When speed goes faster, it is hard to control the small suspension gap rapidly in EMS type. To analyze the EDS-type maglev train, electromagnetic forces were calculated with the superconducting coils and magnets using 2D analytical model. Based on the calculated forces, the lookup tables for the levitation and guidance force were employed in the total couple-fielded analysis. Ultra-high-speed maglev train was simulated by using the ADAMS multi-body dynamic program. The simulation was carried out with two car body models, rigid and flexible car body. In order to construct flexible car bodies with the modal information, the finite element method was used and they were constructed with the equivalent elements using ANSYS™. The final framework was constructed in MATLAB Simulink, and we co-simulated the dynamics and the electromagnetics with the constructed simulation frame work. To consider disturbances caused by irregularities, random and power spectral density (PSD) were used to analyze the vibrational interaction. As results, the ride comforts for PSD were a little bit worse than the results for random irregularity because the characteristics of PSD irregularity have more low excitation frequencies. The use of PSD inputs and flexible car body models need to be considered to improve the simulation accuracy.

     

轨道交通以太网总线TRDP通信实现研究

随着以太网技术逐渐走向成熟,列车上的实时以太网的应用需求日渐增加,尤其是近几年发展迅速的高速列车组.其对以太网通信以及实时性要求越来越高.随着国际电工委员会将以太网列车骨干列入了IEC-61375新的标准中后,针对列车上主要通信方式的研究也慢慢高潮化.其主要研究在列车控制单元VCU(Vehicle Control Un...     

高速动车组多模型切换主动容错预测控制

高速动车组持续高速运行,对控制系统的可靠性和抗干扰能力提出了更高要求.结合高速动车组非线性动力学特点和系统运行数据,应用减法聚类和模式分类算法建立高速动车组多模型集;为适应对象和扰动特性的变化建立高速动车组自适应模型;采用基于累计误差最小的切换策略在线选择最优控制模型,据此设计主动容错预测控制算法来实现高速动车组安全高效运行.最后,仿真实例验证了该方法的有效性.     

铁路移动闭塞系统列车信息的移动性管理

移动闭塞技术已经成功地应用于城市轨道交通,能够提高运输效率,但尚未在铁路上实际应用。该文分析铁路运输相比于城市轨道交通的特殊性和复杂性,讨论列车信息移动性管理对铁路移动闭塞系统的重要性,提出车站“三环节”列车信息动态管理策略和基于双向链表存储结构的区间列车信息动态管理办法,研究基于层次索引的列车信息查询,分析其相关算法和性能。对铁路移动闭塞系统的研究与应用,有一定参考价值。     

Effects of apparent image velocity and complexity on the dynamic visual field using a high-speed train driving simulator

Train driving is a highly visual task. The visual capabilities of the train driver affects driving safety and driving performance. Understanding the effects of train speed and background image complexity on the visual behavior of the high-speed train driver is essential for optimizing performance and safety. This study investigated the role of the apparent image velocity and complexity on the dynamic visual field of drivers. Participants in a repeated-measures experiment drove a train at nine different speeds in a state-of-the-art high-speed train simulator. Eye movement analysis indicated that the effect of image velocity on the dynamic visual field of high-speed train driver was significant while image complexity had no effect on it. The fixation range was increasingly concentrated on the middle of the track as the speed increased, meanwhile there was a logarithmic decline in fixation range for areas surrounding the track. The extent of the visual search field decreased gradually, both vertically and horizontally, as the speed of train increased, and the rate of decrease was more rapid in the vertical direction. A model is proposed that predicts the extent of this tunnel vision phenomenon as a function of the train speed.Relevance to industryThis finding can be used as a basis for the design of high-speed railway system and as a foundation for improving the operational procedures of high-speed train driver for safety.     

基于闭塞区间的高速列车运行时间与节能协同优化方法

提出了一种高速列车运行时间与节能协同优化方法.针对由动态调度层、优化控制层、跟踪控制层组成的列车运行控制与动态调度一体化结构,设计了面向动态调度层和优化控制层的列车运行时间调整策略和节能速度位置曲线.基于高速铁路闭塞区间,建立了列车区间模型和列车速度曲线节能优化模型.利用模型预测控制方法对列车区间运行时间进行调整,优化列车总延误时间;根据调整后的区间运行时间设计列车运行优化速度位置曲线,减少列车运行能耗.仿真算例验证了设计的运行时间与节能协同优化策略的有效性.     

Bridge roughness index as an indicator of bridge dynamic amplification

The concept of a road roughness index for bridge dynamics is developed. The international roughness index (IRI) is shown to be very poorly correlated with bridge dynamic amplification as it takes no account of the location of individual road surface irregularities. It is shown in this paper that a bridge roughness index (BRI) is possible for a given bridge span which is a function only of the road surface profile and truck fleet statistical characteristics. The index is a simple linear combination of the changes in road surface profile; the coefficients are specific to the load effect and span of interest. The BRI is well correlated with bridge dynamic amplification for bending moment due to 2-axle truck crossing events. A similar process can be used to develop a BRI for trucks with other numbers of axles or combinations of trucks meeting on a bridge.     

Rapid,robust, distributed evaluation and control of train scheduling on a single line track

The technology for controlling the distance between two trains is shifting from traditional fixed red, yellow and green signals on the infrastructure track circuits towards more and more dynamic systems, which are based on moving blocks, where the distance is computed according to real-time positioning, and the control of the distance is computed on-line. This is the case, for example, in the European Rail Traffic Management System (ERTMS), which proposes three different levels, from 1 to 3. This paper addresses the time-honoured problem of scheduling trains on a single track, in the light of recent results in robust team decision theory. The control model can be used in two modes: as a decision support tool for train dispatchers to evaluate the distance between trains in the current schedule, and as a planning tool to evaluate the effects of timetable changes. The main contribution of the paper is the application of a recent result in robust team decision theory to control noncritical train distances in moving blocks, such as in ERTMS Level 3. The case study is related to real data from an ERTMS simulation and controller software tool.