Pub Date : 2024-09-01DOI: 10.1016/j.hspr.2024.08.003
Yasuaki Suzuki
East Japan Railway Company (JR East) is aiming to “realize driverless train operation” as one of the key measures to respond to rapid changes in the business environment. Currently, Automatic Train Operation (ATO) equipment is not installed on the Shinkansen, but there are plans to introduce ATO or driverless operation in the near future. From 2018–2021, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) held the “ATO Technology Study Group for Railways” in which the concept of technical requirements necessary for driverless operation was discussed. In 2021, JR East conducted the GOA4 demonstration test on the Joetsu Shinkansen. In this test, we were able to confirm the basic functions of Shinkansen vehicles such as automatic departure control, speed control, fixed position stop control, and remote stop control using ATO. We aim to realize unattended operation (GOA4) for deadhead trains between Niigata Station and the Niigata Shinkansen Rolling Stock Center by the end of the 2020 s, and driverless operation (GOA3) for passenger trains of the Joetsu Shinkansen by the mid-2030s and continue to develop the necessary technologies and build systems.
东日本旅客铁道公司（JR 东日本）将 "实现列车无人驾驶 "作为应对快速变化的商业环境的关键措施之一。目前，新干线上尚未安装列车自动运行（ATO）设备，但计划在不久的将来引进ATO或无人驾驶运行。2018-2021 年，国土交通省召开了 "铁路 ATO 技术研究会"，讨论了无人驾驶运行所需的技术要求概念。2021 年，JR 东日本在上越新干线上进行了 GOA4 演示测试。在这次试验中，我们确认了新干线车辆的基本功能，如自动出发控制、速度控制、固定位置停车控制和使用 ATO 的远程停车控制。我们的目标是到 2020 年代末，在新潟站和新潟新干线车辆中心之间的去程列车上实现无人驾驶（GOA4），到 2030 年代中期，在上越新干线的旅客列车上实现无人驾驶（GOA3），并继续开发必要的技术和构建系统。
{"title":"JR East aims for driverless Shinkansen operation","authors":"Yasuaki Suzuki","doi":"10.1016/j.hspr.2024.08.003","DOIUrl":"10.1016/j.hspr.2024.08.003","url":null,"abstract":"<div><div>East Japan Railway Company (JR East) is aiming to “realize driverless train operation” as one of the key measures to respond to rapid changes in the business environment. Currently, Automatic Train Operation (ATO) equipment is not installed on the Shinkansen, but there are plans to introduce ATO or driverless operation in the near future. From 2018–2021, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) held the “ATO Technology Study Group for Railways” in which the concept of technical requirements necessary for driverless operation was discussed. In 2021, JR East conducted the GOA4 demonstration test on the Joetsu Shinkansen. In this test, we were able to confirm the basic functions of Shinkansen vehicles such as automatic departure control, speed control, fixed position stop control, and remote stop control using ATO. We aim to realize unattended operation (GOA4) for deadhead trains between Niigata Station and the Niigata Shinkansen Rolling Stock Center by the end of the 2020 s, and driverless operation (GOA3) for passenger trains of the Joetsu Shinkansen by the mid-2030s and continue to develop the necessary technologies and build systems.</div></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 3","pages":"Pages 197-201"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 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.
{"title":"Study on the dynamic contact relationship between layers under temperature gradients in CRTSⅢ ballastless track","authors":"Lei Zhao , Guotang Zhao , Guotao Yang , Hao Jin , Chenxi Li","doi":"10.1016/j.hspr.2024.08.001","DOIUrl":"10.1016/j.hspr.2024.08.001","url":null,"abstract":"<div><div>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<sup>−1</sup>.</div></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 3","pages":"Pages 133-142"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 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.
{"title":"Virtually coupled train set control subject to space-time separation: A distributed economic MPC approach with emergency braking configuration","authors":"Xiaolin Luo , Tao Tang , Le Wang , Hongjie Liu","doi":"10.1016/j.hspr.2024.08.002","DOIUrl":"10.1016/j.hspr.2024.08.002","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 3","pages":"Pages 143-152"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 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.
{"title":"A time-space network-based model for transportation service optimization of China Railway Express","authors":"Weichuan Yin , Wenhu Hu , Xueting Yan , Bo Peng , Xiaoling Yang","doi":"10.1016/j.hspr.2024.08.005","DOIUrl":"10.1016/j.hspr.2024.08.005","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 3","pages":"Pages 153-163"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 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.
{"title":"Generalized autoencoder-based fault detection method for traction systems with performance degradation","authors":"","doi":"10.1016/j.hspr.2024.06.001","DOIUrl":"10.1016/j.hspr.2024.06.001","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 3","pages":"Pages 180-186"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141410192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 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.
{"title":"Artificial-intelligent-powered safety and efficiency improvement for controlling and scheduling in integrated railway systems","authors":"Jun Liu , Gehui Liu , Yu Wang , Wanqiu Zhang","doi":"10.1016/j.hspr.2024.06.002","DOIUrl":"10.1016/j.hspr.2024.06.002","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 3","pages":"Pages 172-179"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 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.
{"title":"High-speed railway and safety: Insights from a bibliometric approach","authors":"Apostolos Anagnostopoulos","doi":"10.1016/j.hspr.2024.08.004","DOIUrl":"10.1016/j.hspr.2024.08.004","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 3","pages":"Pages 187-196"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 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.
{"title":"Research on fault time prediction method for high speed rail BTM unit based on multi method interactive validation","authors":"Limin Fu , Junqiang Gou , Chao Sun , Hanrui Li , Wei Liu","doi":"10.1016/j.hspr.2024.07.001","DOIUrl":"10.1016/j.hspr.2024.07.001","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 3","pages":"Pages 164-171"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 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.
{"title":"Optimal allocation method of electric/air braking force of high-speed train considering axle load transfer","authors":"Feng Guo, Jing He","doi":"10.1016/j.hspr.2024.04.004","DOIUrl":"https://doi.org/10.1016/j.hspr.2024.04.004","url":null,"abstract":"<div><p>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.</p></div>","PeriodicalId":100607,"journal":{"name":"High-speed Railway","volume":"2 2","pages":"Pages 77-84"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949867824000308/pdfft?md5=f893352645e3b14ecb17ccb28774ec7e&pid=1-s2.0-S2949867824000308-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141434697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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