High-speed Railway最新文献_第2页

Study on the dynamic contact relationship between layers under temperature gradients in CRTSⅢ ballastless track CRTS Ⅲ型无砟轨道温度梯度下层间动态接触关系研究

High-speed Railway

Pub Date : 2024-09-01 DOI: 10.1016/j.hspr.2024.08.001

Lei Zhao , Guotang Zhao , Guotao Yang , Hao Jin , Chenxi Li

In areas with large temperature differences, the uneven distribution of temperatures in the CRTS III ballastless track slab due to daytime sunlight can cause warpage deformation, leading to periodic rail irregularities that increase the wheel-rail impact of high-speed vehicles and accelerate track structure damage. Therefore, it is necessary to study the dynamic contact relationship between the composite slab and the base plate during vehicle running. The results of the study show that: 1) Under the influence of temperature gradients, the composite slab tends to deform elliptically. With a positive temperature gradient, the middle part of the track slab bulges upward, causing the slab to be supported by its four corners. Conversely, with a negative temperature gradient, the four corners of the track slab bulge upward, resulting in the slab being supported by its center. 2) Temperature gradients can lead to separation between the composite slab and the base plate, reducing the contact area between layers. During vehicle running, the contact area between layers gradually increases, but the separation cannot be completely closed. 3) The temperature gradient significantly affects the vertical displacement of the track. The vertical displacement in the middle of the slab increases with a positive temperature gradient. In contrast, the vertical displacement at the ends of the slab increases with a negative temperature gradient. 4) The stress of self-compacting concrete at the side position significantly increases under a positive temperature gradient, with the vertical stress increasing by 2.7 times when the temperature gradient increases from 0 to 90 ℃·m⁻¹.

在温差较大的地区，由于白天阳光照射，CRTS III 无砟轨道板温度分布不均，会引起翘曲变形，导致轨道周期性不规则，增加高速车辆的轮轨冲击力，加速轨道结构损坏。因此，有必要研究车辆运行过程中复合板与底板的动态接触关系。研究结果表明1) 在温度梯度的影响下，复合材料板倾向于椭圆变形。当温度梯度为正时，轨道板的中间部分向上凸起，导致轨道板由其四个角支撑。相反，当温度梯度为负值时，轨道板的四个角向上凸起，导致板由中心支撑。2) 温度梯度会导致复合材料板与底板分离，减少层间的接触面积。在车辆行驶过程中，层间接触面积逐渐增大，但分离并不能完全闭合。3) 温度梯度对轨道的垂直位移有很大影响。温度梯度为正时，板中间的垂直位移会增加。相反，温度梯度为负时，板两端的垂直位移会增加。4) 在正温度梯度下，侧面位置自密实混凝土的应力显著增加，当温度梯度从 0 增加到 90 ℃-m-1 时，垂直应力增加了 2.7 倍。

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引用次数: 0

Virtually coupled train set control subject to space-time separation: A distributed economic MPC approach with emergency braking configuration 受时空分离影响的虚拟耦合列车组控制：带紧急制动配置的分布式经济 MPC 方法

High-speed Railway

Pub Date : 2024-09-01 DOI: 10.1016/j.hspr.2024.08.002

Xiaolin Luo , Tao Tang , Le Wang , Hongjie Liu

The emerging virtual coupling technology aims to operate multiple train units in a Virtually Coupled Train Set (VCTS) at a minimal but safe distance. To guarantee collision avoidance, the safety distance should be calculated using the state-of-the-art space-time separation principle that separates the Emergency Braking (EB) trajectories of two successive units during the whole EB process. In this case, the minimal safety distance is usually numerically calculated without an analytic formulation. Thus, the constrained VCTS control problem is hard to address with space-time separation, which is still a gap in the existing literature. To solve this problem, we propose a Distributed Economic Model Predictive Control (DEMPC) approach with computation efficiency and theoretical guarantee. Specifically, to alleviate the computation burden, we transform implicit safety constraints into explicitly linear ones, such that the optimal control problem in DEMPC is a quadratic programming problem that can be solved efficiently. For theoretical analysis, sufficient conditions are derived to guarantee the recursive feasibility and stability of DEMPC, employing compatibility constraints, tube techniques and terminal ingredient tuning. Moreover, we extend our approach with globally optimal and distributed online EB configuration methods to shorten the minimal distance among VCTS. Finally, experimental results demonstrate the performance and advantages of the proposed approaches.

新兴的虚拟耦合技术旨在以最小但安全的距离运行虚拟耦合列车组（VCTS）中的多个列车单元。为确保避免碰撞，安全距离的计算应采用最先进的时空分离原理，即在整个紧急制动（EB）过程中分离两个连续单元的紧急制动（EB）轨迹。在这种情况下，最小安全距离通常是通过数值计算得出的，不需要进行分析计算。因此，受约束的 VCTS 控制问题很难通过时空分离来解决，这在现有文献中仍是一个空白。为解决这一问题，我们提出了一种具有计算效率和理论保证的分布式经济模型预测控制（DEMPC）方法。具体来说，为了减轻计算负担，我们将隐式安全约束转化为显式线性约束，这样 DEMPC 中的最优控制问题就是一个可以高效求解的二次编程问题。在理论分析方面，我们利用兼容性约束、管子技术和终端成分调整，得出了保证 DEMPC 递归可行性和稳定性的充分条件。此外，我们还扩展了全局最优和分布式在线 EB 配置方法，以缩短 VCTS 之间的最小距离。最后，实验结果证明了所提方法的性能和优势。

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引用次数: 0

A time-space network-based model for transportation service optimization of China Railway Express 基于时空网络的中铁快运运输服务优化模型

High-speed Railway

Pub Date : 2024-09-01 DOI: 10.1016/j.hspr.2024.08.005

Weichuan Yin , Wenhu Hu , Xueting Yan , Bo Peng , Xiaoling Yang

This paper describes the development and optimization plans for the China Railway Express (CR Express). As a new type of international land transport organization, CR Express has emerged with the continuous expansion of China toward European investment and trade, and in particular, has expanded with the continuous progress of the One Belt and One Road (OBOR) initiative. In addition to improving the service quality of CR Express, the operating costs must be reduced for developing “smart railways” that serve “smart cities”. We propose a dual-objective-based function mathematical optimization model; the satisfaction of the cargo owner is considered, and the timeliness, transportation capacity, and goods category constraints of CR Express transportation are designed. Moreover, we present the normalized equivalent method of the two-objective function of the model. Finally, a case study is conducted against the background of certain trains in the western corridor of CR Express to validate the effectiveness of the model and research methods proposed in this study.

本文介绍了中铁快运（CR Express）的发展和优化计划。作为一种新型的国际陆路运输组织，中铁快运是随着中国对欧洲投资和贸易的不断扩大，特别是随着 "一带一路 "倡议的不断推进而兴起的。要发展服务于 "智慧城市 "的 "智慧铁路"，除了提高中铁快运的服务质量，还必须降低运营成本。我们提出了一个基于双目标函数的数学优化模型；考虑了货主的满意度，并设计了中铁快运运输的及时性、运输能力和货物类别约束。此外，我们还提出了该模型双目标函数的归一化等价方法。最后，以中铁快运西部通道的某些列车为背景进行了案例研究，以验证本研究提出的模型和研究方法的有效性。

引用次数: 0

Generalized autoencoder-based fault detection method for traction systems with performance degradation 基于广义自动编码器的牵引系统故障检测方法 * 性能下降

High-speed Railway

Pub Date : 2024-09-01 DOI: 10.1016/j.hspr.2024.06.001

Fault diagnosis of traction systems is important for the safety operation of high-speed trains. Long-term operation of the trains will degrade the performance of systems, which decreases the fault detection accuracy. To solve this problem, this paper proposes a fault detection method developed by a Generalized Autoencoder (GAE) for systems with performance degradation. The advantage of this method is that it can accurately detect faults when the traction system of high-speed trains is affected by performance degradation. Regardless of the probability distribution, it can handle any data, and the GAE has extremely high sensitivity in anomaly detection. Finally, the effectiveness of this method is verified through the Traction Drive Control System (TDCS) platform. At different performance degradation levels, our method’s experimental results are superior to traditional methods.

牵引系统的故障诊断对高速列车的安全运行非常重要。列车长期运行会导致系统性能下降，从而降低故障检测的准确性。为解决这一问题，本文提出了一种由广义自动编码器（GAE）开发的故障检测方法，适用于性能下降的系统。该方法的优势在于，当高速列车的牵引系统受到性能下降的影响时，它能准确地检测出故障。无论概率分布如何，它都能处理任何数据，而且 GAE 在异常检测方面具有极高的灵敏度。最后，通过牵引传动控制系统（TDCS）平台验证了该方法的有效性。在不同的性能退化水平下，我们方法的实验结果均优于传统方法。

引用次数: 0

Artificial-intelligent-powered safety and efficiency improvement for controlling and scheduling in integrated railway systems 以人工智能为动力，提高综合铁路系统控制和调度的安全性和效率

High-speed Railway

Pub Date : 2024-09-01 DOI: 10.1016/j.hspr.2024.06.002

Jun Liu , Gehui Liu , Yu Wang , Wanqiu Zhang

The multi-mode integrated railway system, anchored by the high-speed railway, caters to the diverse travel requirements both within and between cities, offering safe, comfortable, punctual, and eco-friendly transportation services. With the expansion of the railway networks, enhancing the efficiency and safety of the comprehensive system has become a crucial issue in the advanced development of railway transportation. In light of the prevailing application of artificial intelligence technologies within railway systems, this study leverages large model technology characterized by robust learning capabilities, efficient associative abilities, and linkage analysis to propose an Artificial-intelligent (AI)-powered railway control and dispatching system. This system is elaborately designed with four core functions, including global optimum unattended dispatching, synergetic transportation in multiple modes, high-speed automatic control, and precise maintenance decision and execution. The deployment pathway and essential tasks of the system are further delineated, alongside the challenges and obstacles encountered. The AI-powered system promises a significant enhancement in the operational efficiency and safety of the composite railway system, ensuring a more effective alignment between transportation services and passenger demands.

以高速铁路为核心的多模式综合铁路系统满足了城市内部和城市之间多样化的出行需求，提供了安全、舒适、准时和环保的运输服务。随着铁路网络的扩大，提高综合系统的效率和安全性已成为铁路运输先进发展的关键问题。鉴于人工智能技术在铁路系统中的普遍应用，本研究利用具有强大学习能力、高效联想能力和关联分析能力的大型模型技术，提出了一种人工智能（AI）驱动的铁路控制和调度系统。该系统精心设计了四大核心功能，包括全局最优无人值守调度、多模式协同运输、高速自动控制、精准维护决策与执行。此外，还进一步阐述了该系统的部署路径和基本任务，以及遇到的挑战和障碍。人工智能驱动的系统有望显著提高复合铁路系统的运营效率和安全性，确保运输服务与乘客需求之间更有效的匹配。

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引用次数: 0

High-speed railway and safety: Insights from a bibliometric approach 高速铁路与安全：文献计量学方法的启示

High-speed Railway

Pub Date : 2024-09-01 DOI: 10.1016/j.hspr.2024.08.004

Apostolos Anagnostopoulos

High-Speed Rail (HSR) systems represent a significant advancement in modern transportation. They offer rapid, efficient, and environmentally friendly alternatives to traditional rail, air travel and road transportation. Even if high-speed trains appeared approximately in the middle of the previous century, several aspects concerning safety remain. This study aims to comprehensively review the scientific literature related to the safety issues of high-speed railways. A bibliometric analysis was carried out utilizing 2358 publications from the last two decades (2004–2023) to understand better the existing research on HSR and safety. Future trends and thematic areas of research are identified and analyzed. Chinese researchers and universities have led the total number of current publications related to the context of HSR safety. While most of the publications come from Chinese institutions, a significant international collaboration can be identified. The main areas of research on HSR and safety can be classified into four main clusters based on the keywords co-occurrence analysis and are related to risk management, structural dynamics and resilience in railway systems, geotechnical engineering and tunnelling and maintenance technologies. Researchers and policymakers can use the results of this study to better understand the dynamics of scientific research in the field of high-speed railways and safety and make decisions about future directions and funding priorities.

高速铁路（HSR）系统是现代交通的一大进步。与传统的铁路、航空和公路运输相比，它们提供了快速、高效和环保的替代方案。尽管高速列车大约出现在上世纪中叶，但仍存在一些与安全有关的问题。本研究旨在全面回顾与高速铁路安全问题相关的科学文献。我们利用过去二十年（2004-2023 年）的 2358 篇出版物进行了文献计量分析，以更好地了解有关高速铁路和安全的现有研究。同时还确定并分析了未来的研究趋势和主题领域。中国研究人员和大学在当前与高铁安全相关的出版物总数中遥遥领先。虽然大多数出版物来自中国机构，但也可以发现大量的国际合作。根据关键词共现分析，有关高铁和安全的主要研究领域可分为四大类，分别涉及风险管理、铁路系统的结构动力学和弹性、岩土工程、隧道和维护技术。研究人员和政策制定者可以利用本研究的结果更好地了解高速铁路和安全领域的科研动态，并就未来的研究方向和资助重点做出决策。

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引用次数: 0

Research on fault time prediction method for high speed rail BTM unit based on multi method interactive validation 基于多方法交互验证的高铁 BTM 单元故障时间预测方法研究

High-speed Railway

Pub Date : 2024-09-01 DOI: 10.1016/j.hspr.2024.07.001

Limin Fu , Junqiang Gou , Chao Sun , Hanrui Li , Wei Liu

The Balise Transmission Module (BTM) unit of the on-board train control system is a crucial component. Due to its unique installation position and complex environment, this unit has a higher fault rate within the on-board train control system. To conduct fault prediction for the BTM unit based on actual fault data, this study proposes a prediction method combining reliability statistics and machine learning, and achieves the fusion of prediction results from different dimensions through multi-method interactive validation. Firstly, a method for predicting equipment fault time targeting batch equipment is introduced. This method utilizes reliability statistics to construct a model of the remaining faultless operating time distribution considering uncertainty, thereby predicting the remaining faultless operating probability of the BTM unit. Secondly, considering the complexity of the BTM unit’s fault mechanism, the small sample size of fault cases, and the potential presence of multiple fault features in fault text records, an individual-oriented fault prediction method based on Bayesian-optimized Gradient Boosting Regression Tree (Bayes-GBRT) is proposed. This method achieves better prediction results compared to linear regression algorithms and random forest regression algorithms, with an average absolute error of only 0.224 years for predicting the fault time of this type of equipment. Finally, a multi-method interactive validation approach is proposed, enabling the fusion and validation of multi-dimensional results. The results indicate that the predicted fault time and the actual fault time conform to a log-normal distribution, and the parameter estimation results are basically consistent, verifying the accuracy and effectiveness of the prediction results. The above research findings can provide technical support for the maintenance and modification of BTM units, effectively reducing maintenance costs and ensuring the safe operation of high-speed railway, thus having practical engineering value for preventive maintenance.

车载列车控制系统的平衡传输模块（BTM）单元是一个关键部件。由于其独特的安装位置和复杂的安装环境，该单元在车载列车控制系统中的故障率较高。为了根据实际故障数据对 BTM 单元进行故障预测，本研究提出了一种结合可靠性统计和机器学习的预测方法，并通过多方法交互验证实现了不同维度预测结果的融合。首先，介绍了一种针对批量设备的设备故障时间预测方法。该方法利用可靠性统计构建考虑不确定性的剩余无故障运行时间分布模型，从而预测 BTM 设备的剩余无故障运行概率。其次，考虑到 BTM 机组故障机理的复杂性、故障案例样本量较小、故障文本记录中可能存在多个故障特征等因素，提出了一种基于贝叶斯优化梯度提升回归树（Bayes-GBRT）的面向个体的故障预测方法。与线性回归算法和随机森林回归算法相比，该方法取得了更好的预测效果，在预测此类设备的故障时间时，平均绝对误差仅为 0.224 年。最后，提出了一种多方法交互验证方法，实现了多维结果的融合和验证。结果表明，预测故障时间与实际故障时间符合对数正态分布，参数估计结果基本一致，验证了预测结果的准确性和有效性。上述研究成果可为 BTM 机组的维护和改造提供技术支持，有效降低维护成本，保障高速铁路的安全运行，具有预防性维护的工程实用价值。

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引用次数: 0

Artificial-intelligent-powered safety and efficiency improvement for integrated railway systems 以人工智能为动力，提高综合铁路系统的安全和效率

High-speed Railway

Pub Date : 2024-07-01 DOI: 10.1016/j.hspr.2024.06.006

Jun Liu, Gehui Liu, Yu Wang, Wanqiu Zhang

引用次数: 0

Optimal allocation method of electric/air braking force of high-speed train considering axle load transfer 考虑轴荷转移的高速列车电/气制动力优化分配方法

High-speed Railway

Pub Date : 2024-06-01 DOI: 10.1016/j.hspr.2024.04.004

Feng Guo, Jing He

Reasonable distribution of braking force is a factor for a smooth, safe, and comfortable braking of trains. A dynamic optimal allocation strategy of electric-air braking force is proposed in this paper to solve the problem of the lack of consideration of adhesion difference of train wheelsets in the existing high-speed train electric-air braking force optimal allocation strategies. In this method, the braking strategy gives priority to the use of electric braking force. The force model of a single train in the braking process is analyzed to calculate the change of adhesion between the wheel and rail of each wheelset after axle load transfer, and then the adhesion of the train is estimated in real time. Next, with the goal of maximizing the total adhesion utilization ratio of trailer/motor vehicles, a linear programming distribution function is constructed. The proportional coefficient of adhesion utilization ratio of each train and the application upper limit of braking force in the function is updated according to the change time point of wheelset adhesion. Finally, the braking force is dynamically allocated. The simulation results of Matlab/Simulink show that the proposed algorithm not only uses the different adhesion limits of each trailer to reduce the total amount of braking force undertaken by the motor vehicle, but also considers the adhesion difference of each wheelset. The strategy can effectively reduce the risk and time of motor vehicles during the braking process and improve the stability of the train braking.

合理分配制动力是保证列车制动平稳、安全、舒适的因素之一。本文提出了一种电-气制动力动态优化分配策略，以解决现有高速列车电-气制动力优化分配策略中未考虑列车轮对附着力差异的问题。在该方法中，制动策略优先使用电制动力。通过分析单列列车在制动过程中的受力模型，计算出轴载传递后各轮对轮对与钢轨之间附着力的变化，进而实时估算出列车的附着力。接下来，以挂车/机动车总附着力利用率最大化为目标，构建了线性规划分布函数。根据轮对附着力的变化时间点更新函数中各列车附着力利用率的比例系数和制动力的应用上限。最后，动态分配制动力。Matlab/Simulink 的仿真结果表明，所提出的算法不仅利用了每辆挂车不同的附着力上限来减少机动车所承担的制动力总量，而且还考虑了每个轮组的附着力差异。该策略可有效降低机动车在制动过程中的风险和时间，提高列车制动的稳定性。

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引用次数: 0

Effects of plasma spraying process on microstructure and mechanical properties of Cr2AlC/410 composite coatings 等离子喷涂工艺对 Cr2AlC/410 复合涂层微观结构和机械性能的影响

High-speed Railway

Pub Date : 2024-06-01 DOI: 10.1016/j.hspr.2024.05.001

Yihu Ma , Chaosheng Ma , Guozheng Ma , Wenbo Yu

To investigate the influences of Cr₂AlC mass fraction and supersonic plasma spraying process on the microstructure and mechanical properties of Cr₂AlC reinforced 410 stainless steel composite coatings, the coatings containing different mass fractions of Cr₂AlC were prepared and investigated. The composite coating exhibited low porosity and high adhesion strength. The addition of Cr₂AlC significantly enhanced the hardness of the composite coatings through particle strengthening. However, when the mass fraction of Cr₂AlC was 20%, the aggregation of Cr₂AlC resulted in a strong decrease in the coating preparation efficiency, as well as a decline in adhesion strength. In the supersonic plasma spraying process, the Ar flow rate mainly influenced the flight velocity of the particles, while the H₂ flow rate and the current mainly affected the temperature of the plasma torch. Consequently, all of them influenced the melting degree of particles and the quality of the coating. The lowest porosity and the highest hardness and adhesion strength could be obtained when the Ar flow rate is 125 L/min, the H₂ flow rate is 25 L/min, and the current is 385 A.

为了研究 Cr2AlC 质量分数和超音速等离子喷涂工艺对 Cr2AlC 增强 410 不锈钢复合涂层的微观结构和机械性能的影响，制备并研究了含有不同质量分数 Cr2AlC 的涂层。复合涂层表现出低孔隙率和高附着强度。Cr2AlC 的添加可通过颗粒强化显著提高复合涂层的硬度。然而，当 Cr2AlC 的质量分数为 20% 时，Cr2AlC 的聚集导致涂层制备效率大大降低，附着强度也有所下降。在超音速等离子喷涂过程中，氩气流量主要影响颗粒的飞行速度，而 H2 流量和电流主要影响等离子炬的温度。因此，它们都会影响颗粒的熔化程度和涂层质量。当 Ar 流速为 125 L/min、H2 流速为 25 L/min 和电流为 385 A 时，孔隙率最低，硬度和附着强度最高。

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引用次数: 0