列车安全距离控制形式化建模与验证

随着我国铁路的迅速发展,对列车运行安全性的要求越来越高。采用Event-B形式化建模方法研究了高速列车安全距离控制形式化验证问题,以Event-B形式化仿真工具Rodin为基础,通过结合多智能体理论,引入感知决策法则,实现了无线闭塞中心(RBC)与列车的车地通信,建立了多列车运行的安全距离控制模型。仿真研究了高速列车最小间隔追踪控制运行,对列车安全距离控车行为进行了形式化建模并进行了POs证明义务验证。仿真结果表明,对于CTCS列车控制系统的复杂逻辑关联行为,采用提出的Event-B和多智能体系统(MAS)结合的形式化验证方法,可进行系统规范的模型验证,对于复杂系统的逻辑验证有较强的实际意义。     

Rescheduling rail networks with maintenance disruptions using Problem Space Search

The creation of train timetables for long-haul single track networks is a challenging process. This task is more difficult if track maintenance disruptions are to be taken into account. This paper describes how the Problem Space Search (PSS) meta-heuristic can be used for large scale problems to create quality timetables in which both train movements and scheduled track maintenance are simultaneously considered. We show that the PSS meta-heuristic can rapidly generate a large number of alternative train timetables and then describe how the technique is generalized to construct an integrated timetable which includes track maintenance. We show how the technique can also be used as an operational tool where a revised schedule can be quickly generated to take into account the new state of a disrupted system. A case study for a single track rail network in Queensland Australia, which spans a distance of 480 km, has 57 crossing loops and typically carries over 50 trains per day is discussed.     

基于编队技术的地铁列车运行控制研究

首先分析了移动闭塞条件下地铁列车的运行规律,建立了地铁列车的动力学模型,研究移动闭塞条件下地铁列车车组间的控制,采用基于事件的控制理论和编队技术降低列车间的最小追踪允许间隔,在保证不撞车以及尽量减少站外停车的前提下,提高地铁线路的通过能力,并且能够方便地实现系统的重新配置以及各子系统间的协调协作。以相邻的三列列车运行为例,研究在移动闭塞条件下后续列车的控制策略,根据列车的走行距离以及前后列车间所要求保留的安全距离,动态调整列车的运行速度、加速度。     

基于预测控制的列车精确停车算法

精确停车是评价列车自动驾驶性能的关键指标之一。在分析列车停车阶段运行情况的基础上,考虑制动模型的延迟特性和列车运行特性的约束条件,运用广义预测控制理论,将列车运行的参考速度和参考距离作为控制目标,结合控制量所需满足的约束条件,设计了一种带约束的多目标预测控制器,以提高停车精度和列车运行的舒适性。通过仿真实例表明,该控制器不仅可以使列车精确跟踪停车目标曲线,达到高精度的停车要求,而且使列车运行具有更高的舒适性。     

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.     

The periodicity and robustness in a single-track train scheduling problem

The most important operating problem in any railway industry is to produce robust train timetables with minimum delays. The train scheduling problem is defined as an application of job shop scheduling which is considered to be one of the most interesting research topics. This paper deals with scheduling different types of trains in a single railway track. The authors have focused on the robust and periodic aspects of produced timetables. This paper is also concerned with some applicable constraints, such as the acceleration and deceleration times, station capacity and headway constraints. The periodic timetable for railways is modeled based on the periodic event scheduling problem (PESP). Furthermore, a fuzzy approach is used to reach a tradeoff among the total train delays, the robustness of schedules, and the time interval between departures of trains from the same origins. To solve large-scale problems, a meta-heuristic algorithm based on simulated annealing (SA) is utilized and validated using some numerical examples on a periodic robust train scheduling problem. Finally, a robustness measure is defined in order to assure the effectiveness of the proposed SA to find robust solutions.     

基于时间博弈自动机的道岔自动控制系统

为提高道岔自动控制系统的运行效率,引入时间博弈自动机理论,建立列车、控制器、道岔和故障检测器的时间博弈自动机网络模型,使用TCTL公式描述获胜条件,应用策略综合工具Uppaal-Tiga输出获胜策略并生成控制代码。仿真结果表明,该控制策略可以有效提高列车的行车效率。     

采用预测控制的地铁节能优化控制算法

本文针对地铁列车自动运行系统(automatic train operation,ATO)一般运行情况以及晚点延迟发车情况下的节能问题,基于预测控制算法设计了地铁节能优化控制算法.利用预测控制算法的在线滚动优化特性,通过设计含有能量消耗趋势优化项的控制目标函数,控制算法能够针对节能目标实现快速动态调整.通过调节目标函数中各优化项权重的相对大小,节能算法可以在满足列车时间与路程运行指标的同时,达到降低能耗的目的.在MATLAB平台上利用真实车辆模型对提出的节能优化控制算法进行了仿真,在列车不延迟与延迟的情况下,算法都很好地平衡了跟踪目标与节能目标,为地铁能耗动态优化控制提供了可行方案.     

Approaches to modeling train scheduling problems as job-shop problems with blocking constraints

The problem of scheduling a set of trains traveling through a given railway network consisting of single tracks, sidings and stations is considered. For every train a fixed route and travel times, an earliest departure time at the origin and a desired arrival time at the destination are given. A feasible schedule has to be determined which minimizes total tardiness of all trains at their destinations. This train scheduling problem is modeled as a job-shop scheduling problem with blocking constraints, where jobs represent trains and machines constitute tracks or track sections. Four MIP formulations without time-indexed variables are developed based on two different transformation approaches of parallel tracks and two different types of decision variables leading to job-shop scheduling problems with or without routing flexibility. A computational study is made on hard instances with up to 20 jobs and 11 machines to compare the MIP models in terms of total tardiness values, formulation size and computation time.     

降低参数灵敏度的磁浮列车鲁棒悬浮控制器设计

磁浮列车的悬浮静态工作点与承载重量有关,因此对悬浮控制器的设计提出了更高的要求.以八达岭磁浮列车旅游线用的CMS-3型磁浮列车为研究对象,在分析磁浮列车悬浮控制系统的数学模型基础上,应用降低参数灵敏度的鲁棒控制器设计法对悬浮控制器进行设计,使控制器对列车质量变化的参数灵敏度明显降低.     

列车网络控制系统研究

随着世界各国经济的发展,城市规模和人口规模的扩大,城市交通变得更加拥堵,许多发达国家在多年前就着手研究如何使用轨道交通解决城市的拥堵问题,地铁已成为当今城市交通的重要组成部分,地铁列车在运营过程中如何保证其运行状态能够实时受到监控,靠的就是列车网络系统;文章介绍了海外某项目的 网络系统结构、硬件配置;阐述了列车级控制、牵引系统、车窗系统、辅助系统、制动系统、空调系统、烟火系统等子系统的关键控制功能,并对系统的故障诊断功能、PTU功能进行了介绍;本项目网络系统的设计符合预期,系统硬件的性能完全满足功能需求,系统软件的可靠性、稳定性达到了列车运行要求.     

有向图中网络Euler-Lagrange系统的自适应协调跟踪

基于一致性理论, 在有向图中研究网络 Euler-Lagrange 系统的协调跟踪控制. 所有跟随智能体的动力学模型均为 Euler-Lagrange 方程. 在仅有部分跟随智能体能获取领航智能体信息的情形下, 同时考虑系统模型的参数不确定性, 设计分布式自适应控制律实现所有跟随智能体对领航智能体的跟踪. 针对领航智能体的运动状态, 考虑以下两种情形: 1) 领航智能体为固定点; 2) 领航智能体为动态点. 对第一种情形, 设计的控制律使得所有跟随智能体渐近交会于固定点; 对第二种情形, 首先对每个跟随智能体设计分布式连续估计器, 然后提出了分布式自适应控制律. 当每个跟随智能体均能获取领航智能体的加速度信息时, 设计的控制律能实现对领航智能体的渐近跟踪, 当跟随智能体不能获取领航智能体的加速度信息时, 跟踪误差是有界的. 最后通过仿真分析验证设计的控制算法是合理有效的.     

Availability assessment of railway signalling systems with uncertainty analysis using Statecharts

In this paper, we propose an original simulation approach to evaluate the availability of systems in the presence of state uncertainty which arises from incompleteness or imprecision of knowledge and data. This approach is based on a simulation method combining the belief functions theory and the Statecharts. Then we propose a Statechart model of a railway signalling system, European Rail Traffic Management System (ERTMS) Level 2 considering state uncertainty, and evaluate its availability according to the RAMS requirements defined in the railway standards. Finally we propose a sensitivity analysis to estimate the state uncertainty of which constituent system has the most significant influence on the state uncertainty of the entire ERTMS Level 2.     

Scheduling trains as a blocking parallel-machine job shop scheduling problem

In this paper, the train scheduling problem is modelled as a blocking parallel-machine job shop scheduling (BPMJSS) problem. In the model, trains, single-track sections and multiple-track sections, respectively, are synonymous with jobs, single machines and parallel machines, and an operation is regarded as the movement/traversal of a train across a section. Due to the lack of buffer space, the real-life case should consider blocking or hold-while-wait constraints, which means that a track section cannot release and must hold the train until next section on the routing becomes available. Based on literature review and our analysis, it is very hard to find a feasible complete schedule directly for BPMJSS problems. Firstly, a parallel-machine job-shop-scheduling (PMJSS) problem is solved by an improved shifting bottleneck procedure (SBP) algorithm without considering blocking conditions. Inspired by the proposed SBP algorithm, feasibility satisfaction procedure (FSP) algorithm is developed to solve and analyse the BPMJSS problem, by an alternative graph model that is an extension of the classical disjunctive graph models. The proposed algorithms have been implemented and validated using real-world data from Queensland Rail. Sensitivity analysis has been applied by considering train length, upgrading track sections, increasing train speed and changing bottleneck sections. The outcomes show that the proposed methodology would be a very useful tool for the real-life train scheduling problems.     

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。     

A new multi-criteria weighting and ranking model for group decision-making analysis based on interval-valued hesitant fuzzy sets to selection problems

The multi-criteria group decision-making methods under fuzzy environments are developed to cope with imprecise and uncertain information for solving the complex group decision-making problems. A team of some professional experts for the assessment is established to judge candidates or alternatives among the chosen evaluation criteria. In this paper, a novel multi-criteria weighting and ranking model is introduced with interval-valued hesitant fuzzy setting, namely IVHF-MCWR, based on the group decision analysis. The interval-valued hesitant fuzzy set theory is a powerful tool to deal with uncertainty by considering some interval-values for an alternative under a set regarding assessment factors. In procedure of the proposed IVHF-MCWR model, weights of criteria as well as experts are considered to decrease the errors. In this regard, optimal criteria’ weights are computed by utilizing an extended maximizing deviation method based on IVHF-Hamming distance measure. In addition, experts’ judgments are taken into account for computing the criteria’ weights. Also, experts’ weights are determined based on proposed new IVHF technique for order performance by similarity to ideal solution method. Then, a new IVHF-index based on Hamming distance measure is introduced to compute the relative closeness coefficient for ranking the candidates or alternatives. Finally, two application examples about the location and supplier selection problems are considered to indicate the capability of the proposed IVHF-MCWR model. In addition, comparative analysis is reported to compare the proposed model and three fuzzy decision methods from the recent literature. Comparing these approaches and computational results shows that the IVHF-MCWR model works properly under uncertain conditions.     

Energy-efficient receding horizon trajectory planning of high-speed trains using real-time traffic information

Optimal trajectory planning of high-speed trains (HSTs) aims to obtain such speed curves that guarantee safety, punctuality, comfort and energy-saving of the train. In this paper, a new shrinking horizon model predictive control (MPC) algorithm is proposed to plan the optimal trajectories of HSTs using real-time traffic information. The nonlinear longitudinal dynamics of HSTs are used to predict the future behaviors of the train and describe variable slopes and variable speed limitations based on real-time traffic information. Then optimal trajectory planning of HSTs is formulated as the shrinking horizon optimal control problem with the consideration of safety, punctuality, comfort and energy consumption. According to the real-time position and running time of the train, the shrinking horizon is updated to ensure the recursive feasibility of the optimization problem. The optimal speed curve of the train is computed by online solving the optimization problem with the Radau Pseudo-spectral method (RPM). Simulation results demonstrate that the proposed method can satisfy the requirements of energy efficiency and punctuality of the train.     

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.     

鲁棒控制理论应用于宏观经济系统分析

针对宏观经济系统模型的不确定性，运用鲁棒控制理论进行宏观经济系统的分析与决策，使得宏观经济系统能够保持鲁棒稳定性并准确跟踪预先给定的目标。     

温州动车追尾事故与CTCS-2技术规范中的安全隐患

2011年7月23日在温州附近不幸发生动车追尾，本文指出列控技术规范的变化可能同事故有关系。CTCS-2列控技术规范2007年版中引入了“三点检查”技术，理论上它能够在轨道电路故障情况下保障列车安全运行。如果在7月23日的故障状态下采用这一技术，调度可以在故障路段放入多辆列车，某些故障路段可能亮绿灯让列车正常通过，该技术将通过防护点保障安全。可能由于技术不够成熟的原因，CTCS-2技术规范2010年版中删除了这一措施，在新增的故障处理条款中没有明确说明设备故障需要亮红灯。如果此后调度按照过去的方式处理，很可能发生事故。