Pub Date : 2023-04-05DOI: 10.1177/09544097231168035
Bo Wang, S. Luo, Weihua Ma, Guanchun Li, Zhiyun Wang, Jie Xu, Xiaoxu Zhang
In vehicle dynamics research, a dynamics model is essential, as it provides the basis for the demonstration of early system design of vehicle as well as the verification and optimization of the dynamics performance of the final product. To promote the development of a permanent magnet (PM) Electrodynamic Suspension (EDS) in a maglev train, research was carried out in order to explore a fast dynamics modeling, with suspension system based on two-sided PM. First of all, a halbach array was taken as the object of study, with the analytical solution of its magnetic force obtained by theoretical derivation according to magnet filed and 2D analytical method; then, the magnetic force was discretized into a data matrix of displacement, force, and speed; thirdly, the data matrix was introduced in SIMPACK to establish a magnet-track relationship in scalar form, and a dynamics model of the two-sided PM EDS maglev system was finished by the theory of multi-body dynamics modeling; finally, the proposed modeling was validated by the agreement between theoretical derivation and dynamics model calculation of the heaving frequency and pitching frequency of the frame; at the same time, it was also validated by the agreement of dynamic responses between the modeling by vehicle-track coupled dynamics theory and the dynamic model calculation of the levitation gap and force. According to the established dynamics model, dynamic response of the system at the speed of 600 km/h was calculated, and the feasibility of the two-sided PM EDS maglev train was verified. The simulation speed of model which was established before is 50 times that of the mathematical model by the vehicle-track coupled dynamics, thus providing reference for the future research in this regard.
{"title":"A fast dynamic model of a two-sided permanent magnet electrodynamic suspension system in a maglev train","authors":"Bo Wang, S. Luo, Weihua Ma, Guanchun Li, Zhiyun Wang, Jie Xu, Xiaoxu Zhang","doi":"10.1177/09544097231168035","DOIUrl":"https://doi.org/10.1177/09544097231168035","url":null,"abstract":"In vehicle dynamics research, a dynamics model is essential, as it provides the basis for the demonstration of early system design of vehicle as well as the verification and optimization of the dynamics performance of the final product. To promote the development of a permanent magnet (PM) Electrodynamic Suspension (EDS) in a maglev train, research was carried out in order to explore a fast dynamics modeling, with suspension system based on two-sided PM. First of all, a halbach array was taken as the object of study, with the analytical solution of its magnetic force obtained by theoretical derivation according to magnet filed and 2D analytical method; then, the magnetic force was discretized into a data matrix of displacement, force, and speed; thirdly, the data matrix was introduced in SIMPACK to establish a magnet-track relationship in scalar form, and a dynamics model of the two-sided PM EDS maglev system was finished by the theory of multi-body dynamics modeling; finally, the proposed modeling was validated by the agreement between theoretical derivation and dynamics model calculation of the heaving frequency and pitching frequency of the frame; at the same time, it was also validated by the agreement of dynamic responses between the modeling by vehicle-track coupled dynamics theory and the dynamic model calculation of the levitation gap and force. According to the established dynamics model, dynamic response of the system at the speed of 600 km/h was calculated, and the feasibility of the two-sided PM EDS maglev train was verified. The simulation speed of model which was established before is 50 times that of the mathematical model by the vehicle-track coupled dynamics, thus providing reference for the future research in this regard.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87847140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-03DOI: 10.1177/09544097231166472
P. Leibner, Fabian Hampel, C. Schindler
In recent years, a strong push towards driverless mobility solutions can be seen in many transportation sectors including railways. While the European Train Control System already specifies the necessary interfaces to open up the possibility of Automatic Train Operation (ATO) for mainline railway vehicles, required infrastructure-side upgrades of interlocking systems are time- and cost-intensive. Alternatively, a pure vehicle-side Automatic Train Operation solution can be conceptualized that relies on processing the same audio-visual input a human train driver would normally base his decisions on. This would require the vehicle-side detection of track-side railway signals to determine the vehicle’s movement authority and allowed maximum speed. Such a signal detection system could furthermore be employed as an Advanced Driver Assistance System (ADAS) or support autonomous shunting operations. To enable such a system, this paper presents GERALD, a novel dataset for a neural network based detection approach of railway signals. The dataset contains 5000 images from a wide variety of railway scenes as well as annotations for the most common types of German mainline railway signals. The material was gathered using publicly available cab-view recordings uploaded by railway enthusiasts on YouTube. Using a state of the art neural network architecture for evaluation, we notice promising detection accuracies despite GERALD being a comparably small dataset. The dataset is freely available for research and non-commercial purposes at: https://github.com/ifs-rwth-aachen/GERALD
{"title":"GERALD: A novel dataset for the detection of German mainline railway signals","authors":"P. Leibner, Fabian Hampel, C. Schindler","doi":"10.1177/09544097231166472","DOIUrl":"https://doi.org/10.1177/09544097231166472","url":null,"abstract":"In recent years, a strong push towards driverless mobility solutions can be seen in many transportation sectors including railways. While the European Train Control System already specifies the necessary interfaces to open up the possibility of Automatic Train Operation (ATO) for mainline railway vehicles, required infrastructure-side upgrades of interlocking systems are time- and cost-intensive. Alternatively, a pure vehicle-side Automatic Train Operation solution can be conceptualized that relies on processing the same audio-visual input a human train driver would normally base his decisions on. This would require the vehicle-side detection of track-side railway signals to determine the vehicle’s movement authority and allowed maximum speed. Such a signal detection system could furthermore be employed as an Advanced Driver Assistance System (ADAS) or support autonomous shunting operations. To enable such a system, this paper presents GERALD, a novel dataset for a neural network based detection approach of railway signals. The dataset contains 5000 images from a wide variety of railway scenes as well as annotations for the most common types of German mainline railway signals. The material was gathered using publicly available cab-view recordings uploaded by railway enthusiasts on YouTube. Using a state of the art neural network architecture for evaluation, we notice promising detection accuracies despite GERALD being a comparably small dataset. The dataset is freely available for research and non-commercial purposes at: https://github.com/ifs-rwth-aachen/GERALD","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85106445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
By establishing the ballast track full scale model, this paper tested and compared the difference between the resistance of the sleeper group and the resistance of a single sleeper, and studied the effect of sleeper group on lateral resistance. The model of the ballast bed was established based on the discrete element method. We compared the lateral resistance of ballast bed composed of different number of sleepers and analyzed the particle movement and the contact characteristic. According to case calculations, we analyzed the lateral stability of continuous welded rail (CWR) considering the effect of sleeper group. The results show that the average resistance of five sleepers decreased by about 28% compared with that of a single sleeper. With the increase of sleeper’s number, the average resistance gradually becomes stable. The reduction of lateral resistance under the effect of sleeper group mainly occurs in the ballast side and sleeper end area and there is a common area of resistance at the side and end of sleepers. When the sleeper displacement reaches 2 mm, the contribution rate of crib resistance in the independent area and the common area is about 4.3:1:1, and the contribution rate of shoulder resistance is about 3.2:1:1. To ensure the safety of the CWR operation, it is suggested that at least three sleepers should be pushed at the same time when testing the lateral resistance and use the average lateral resistance as a reference value.
{"title":"Study of the lateral resistance characteristics of ballast bed considering the sleeper group effect","authors":"Pu-Han Jing, Jie-ling Xiao, Yi Xu, Lixue Zhuang, Si-Xin Yu, Ping Wang, Hao Liu, Tianyou Qi","doi":"10.1177/09544097231167730","DOIUrl":"https://doi.org/10.1177/09544097231167730","url":null,"abstract":"By establishing the ballast track full scale model, this paper tested and compared the difference between the resistance of the sleeper group and the resistance of a single sleeper, and studied the effect of sleeper group on lateral resistance. The model of the ballast bed was established based on the discrete element method. We compared the lateral resistance of ballast bed composed of different number of sleepers and analyzed the particle movement and the contact characteristic. According to case calculations, we analyzed the lateral stability of continuous welded rail (CWR) considering the effect of sleeper group. The results show that the average resistance of five sleepers decreased by about 28% compared with that of a single sleeper. With the increase of sleeper’s number, the average resistance gradually becomes stable. The reduction of lateral resistance under the effect of sleeper group mainly occurs in the ballast side and sleeper end area and there is a common area of resistance at the side and end of sleepers. When the sleeper displacement reaches 2 mm, the contribution rate of crib resistance in the independent area and the common area is about 4.3:1:1, and the contribution rate of shoulder resistance is about 3.2:1:1. To ensure the safety of the CWR operation, it is suggested that at least three sleepers should be pushed at the same time when testing the lateral resistance and use the average lateral resistance as a reference value.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75899802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-31DOI: 10.1177/09544097231166477
C. Cole, Y. Sun, Qing Wu, M. Spiryagin
As efforts are being made to quickly adopt zero carbon technologies and replace fossil fuel powered trains, the design requirements are explored using train dynamics simulations to establish energy needs. The test case was a freight train of 3030 gross tonnes consisting of two locomotives and thirty wagons operating on a relatively flat coastal rail route. Then, assuming rapid deployment of existing and near market technologies, speculative locomotive designs are proposed for both battery only and hydrogen-battery systems. Batteries were assumed as rack mounted systems and hydrogen assumed at 250 bar gaseous. The results showed that full recovery of dynamic braking required only a very small amount of storage to capture and allow re-use, requiring a battery of only 6% of the trip total of recovered energy. The haulage task was found to require traction energy of 10.7 MWh per locomotive but reduced to a net requirement of 7.6 MWh per locomotive with recovery of dynamic braking energy. The large mass of batteries needed for the operating trip, however, limits the practical operating range. The results showed that, although hydrogen storage and equipment occupy considerable space and the containment systems have large mass, the space and mass requirements for a hydrogen system in this case study could be as low as half that required for batteries, while higher pressure or cryogenic approaches to hydrogen storage will allow the scaling for longer range.
{"title":"Exploring hydrogen fuel cell and battery freight locomotive options using train dynamics simulation","authors":"C. Cole, Y. Sun, Qing Wu, M. Spiryagin","doi":"10.1177/09544097231166477","DOIUrl":"https://doi.org/10.1177/09544097231166477","url":null,"abstract":"As efforts are being made to quickly adopt zero carbon technologies and replace fossil fuel powered trains, the design requirements are explored using train dynamics simulations to establish energy needs. The test case was a freight train of 3030 gross tonnes consisting of two locomotives and thirty wagons operating on a relatively flat coastal rail route. Then, assuming rapid deployment of existing and near market technologies, speculative locomotive designs are proposed for both battery only and hydrogen-battery systems. Batteries were assumed as rack mounted systems and hydrogen assumed at 250 bar gaseous. The results showed that full recovery of dynamic braking required only a very small amount of storage to capture and allow re-use, requiring a battery of only 6% of the trip total of recovered energy. The haulage task was found to require traction energy of 10.7 MWh per locomotive but reduced to a net requirement of 7.6 MWh per locomotive with recovery of dynamic braking energy. The large mass of batteries needed for the operating trip, however, limits the practical operating range. The results showed that, although hydrogen storage and equipment occupy considerable space and the containment systems have large mass, the space and mass requirements for a hydrogen system in this case study could be as low as half that required for batteries, while higher pressure or cryogenic approaches to hydrogen storage will allow the scaling for longer range.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80977328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-30DOI: 10.1177/09544097231165087
Shuai Ma, Xiubo Liu, Bo Zhang, W. Qiang, Jianmei Wei
Track geometry inspection data have long endured positional errors and shifts, hindering the quality evaluation, deterioration analysis and maintenance work of railway track. Besides, vehicle response inspection data are also typically misaligned or shifted from each other, but it tends to be ignored by people. In light of this situation, a position calibration method on the basis of a simple similarity metric, i.e. correlation coefficient, is proposed to tackle the positional errors and shifts among multisource track inspection data concurrently. For the convenience of practical implementation, a scheme containing three parts is designed to fulfil the purpose and a two-step procedure is adopted by all the three parts. According to the performance test on a dataset containing five inspection runs of a high-speed railway in China, the positional error between inspection data and actual locations can be greatly diminished, and the data inspected at different times and from different sources are well aligned with each other, with a time consumption of 0.66 s on average for a 1 km segment.
{"title":"Similarity based position calibration for multisource track inspection data","authors":"Shuai Ma, Xiubo Liu, Bo Zhang, W. Qiang, Jianmei Wei","doi":"10.1177/09544097231165087","DOIUrl":"https://doi.org/10.1177/09544097231165087","url":null,"abstract":"Track geometry inspection data have long endured positional errors and shifts, hindering the quality evaluation, deterioration analysis and maintenance work of railway track. Besides, vehicle response inspection data are also typically misaligned or shifted from each other, but it tends to be ignored by people. In light of this situation, a position calibration method on the basis of a simple similarity metric, i.e. correlation coefficient, is proposed to tackle the positional errors and shifts among multisource track inspection data concurrently. For the convenience of practical implementation, a scheme containing three parts is designed to fulfil the purpose and a two-step procedure is adopted by all the three parts. According to the performance test on a dataset containing five inspection runs of a high-speed railway in China, the positional error between inspection data and actual locations can be greatly diminished, and the data inspected at different times and from different sources are well aligned with each other, with a time consumption of 0.66 s on average for a 1 km segment.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85960691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-28DOI: 10.1177/09544097231160613
Fábio C. Barbosa
The rail transport industry has been required to engage with the world effort to reduce the climate effects, as well as the reduction of criteria pollutant and noise emissions, which strongly affects the populations nearby the rail infrastructure. Electric powertrains have been widely used by railways, with its inherent efficiency and cleanliness. However, the required infrastructure has restricted its use to medium to large density traffic corridors, given the large infrastructure and maintenance costs involved. Light to medium loaded rail stretches and large freight rail corridors, running in rural areas, have adopted the diesel-electric powertrain approach, that relies on an onboard diesel generator, with the inherent environmental negative effects, especially to the rail nearby communities. In this context, alternative traction technologies, such as Hybrid-Electric Rail, Hydrogen Fuel Cell Rail and Battery Only Electric Rail, have been considered by the rail industry as potential alternatives. The BOER route, due to the recent battery technology breakthroughs (associated with performance improvements and reduced costs) is set as a promising alternative and has a potential do be used as a decarbonization strategy for both passenger and freight rail systems at low to medium density traffic lines. Nevertheless, the BOER technology sets great challenges, given the high energy and power required by rail vehicles, as well as the harsh rail operational environment, with huge effects on the performance, charging infrastructure requirements, fleet availability, costs, as well as the environmental sustainability associated with the mining and disposal of materials required by the battery chemistries. This paper presents, based on the state of the art available technical literature, an unbiased review of the BOER technology and an assessment of its potential for the freight rail industry, highlighting the associated technical, operational and environmental challenges.
{"title":"Battery only electric traction for freight trains - A technical and operational assessment","authors":"Fábio C. Barbosa","doi":"10.1177/09544097231160613","DOIUrl":"https://doi.org/10.1177/09544097231160613","url":null,"abstract":"The rail transport industry has been required to engage with the world effort to reduce the climate effects, as well as the reduction of criteria pollutant and noise emissions, which strongly affects the populations nearby the rail infrastructure. Electric powertrains have been widely used by railways, with its inherent efficiency and cleanliness. However, the required infrastructure has restricted its use to medium to large density traffic corridors, given the large infrastructure and maintenance costs involved. Light to medium loaded rail stretches and large freight rail corridors, running in rural areas, have adopted the diesel-electric powertrain approach, that relies on an onboard diesel generator, with the inherent environmental negative effects, especially to the rail nearby communities. In this context, alternative traction technologies, such as Hybrid-Electric Rail, Hydrogen Fuel Cell Rail and Battery Only Electric Rail, have been considered by the rail industry as potential alternatives. The BOER route, due to the recent battery technology breakthroughs (associated with performance improvements and reduced costs) is set as a promising alternative and has a potential do be used as a decarbonization strategy for both passenger and freight rail systems at low to medium density traffic lines. Nevertheless, the BOER technology sets great challenges, given the high energy and power required by rail vehicles, as well as the harsh rail operational environment, with huge effects on the performance, charging infrastructure requirements, fleet availability, costs, as well as the environmental sustainability associated with the mining and disposal of materials required by the battery chemistries. This paper presents, based on the state of the art available technical literature, an unbiased review of the BOER technology and an assessment of its potential for the freight rail industry, highlighting the associated technical, operational and environmental challenges.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82134496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-28DOI: 10.1177/09544097231165093
Weigang Wen, Y. Liu, Yihao Bai, Qingzhou Meng
The railway system is an important part of the transportation system. Its scheduling process is carried out by the switch machines. The accuracy of determining the health status of the switch machines is related to the operational efficiency and reliability of the whole system. However, manual fault diagnosis for these machines is always unstable and expensive. The intelligent fault diagnosis (IFD) method can perform accurate fault diagnosis at low cost and high efficiency, but requires a large amount of labeled data. In this case, this study realizes the Feature Pseudo-Fusion (FPF) of left and right oil pressure signals of the electro-hydraulic switch machine. It uses contrastive learning to regularize the feature representation of original signals. Based on FPF, a fault diagnosis method applicable to electro- hydraulic switch machines is constructed. This method reduces the need for labeled data laterally without introducing additional measurement content to the field signal acquisition system. The effectiveness of FPF and the superiority of the fault diagnosis method have been verified through experiments.
{"title":"A feature pseudo-fusion method for intelligent fault diagnosis of electro-hydraulic switch machine inspired by contrastive learning","authors":"Weigang Wen, Y. Liu, Yihao Bai, Qingzhou Meng","doi":"10.1177/09544097231165093","DOIUrl":"https://doi.org/10.1177/09544097231165093","url":null,"abstract":"The railway system is an important part of the transportation system. Its scheduling process is carried out by the switch machines. The accuracy of determining the health status of the switch machines is related to the operational efficiency and reliability of the whole system. However, manual fault diagnosis for these machines is always unstable and expensive. The intelligent fault diagnosis (IFD) method can perform accurate fault diagnosis at low cost and high efficiency, but requires a large amount of labeled data. In this case, this study realizes the Feature Pseudo-Fusion (FPF) of left and right oil pressure signals of the electro-hydraulic switch machine. It uses contrastive learning to regularize the feature representation of original signals. Based on FPF, a fault diagnosis method applicable to electro- hydraulic switch machines is constructed. This method reduces the need for labeled data laterally without introducing additional measurement content to the field signal acquisition system. The effectiveness of FPF and the superiority of the fault diagnosis method have been verified through experiments.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77920150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-26DOI: 10.1177/09544097231160362
Yongsheng Li, H. Dai, Yayun Qi, Sheng Qu, Yi Sun
As the key part of the rail vehicle, the bogie’s dynamic performance directly affects the vehicle’s operating performance. A large number of bogie instability phenomena occur during the operation of high-speed Electric Multiple Units (EMUs), which has an important impact on the safety and passenger comfort of the high-speed EMUs. In this paper, through a combination of line tests and simulations to study bogie hunting, line tests are first conducted to test the vibration data and wheel wear evolution of the high-speed EMUs. The data was analyzed to find out the evolution of the bogie instability law of the high-speed EMUs. Then the vehicle dynamic model is established to find out the mechanism of the bogie instability, and finally bogie instability suppression measures are proposed. The results of the test data showed that the wheel wear, the frequency and the amplitude of bogie instability of motor car is greater than that of the trailer car, and the ride index is poorer. The ride indexes at the early and late stages after wheel re-profiling do not exceed 2.5. The equivalent conicity increase is the main cause of bogie instability, and the bogie instability can be effectively suppressed by wheel re-profiling, replacing the yaw damper, and the rail grinding.
{"title":"Experimental study of bogie instability monitoring and suppression measures for high-speed EMUs","authors":"Yongsheng Li, H. Dai, Yayun Qi, Sheng Qu, Yi Sun","doi":"10.1177/09544097231160362","DOIUrl":"https://doi.org/10.1177/09544097231160362","url":null,"abstract":"As the key part of the rail vehicle, the bogie’s dynamic performance directly affects the vehicle’s operating performance. A large number of bogie instability phenomena occur during the operation of high-speed Electric Multiple Units (EMUs), which has an important impact on the safety and passenger comfort of the high-speed EMUs. In this paper, through a combination of line tests and simulations to study bogie hunting, line tests are first conducted to test the vibration data and wheel wear evolution of the high-speed EMUs. The data was analyzed to find out the evolution of the bogie instability law of the high-speed EMUs. Then the vehicle dynamic model is established to find out the mechanism of the bogie instability, and finally bogie instability suppression measures are proposed. The results of the test data showed that the wheel wear, the frequency and the amplitude of bogie instability of motor car is greater than that of the trailer car, and the ride index is poorer. The ride indexes at the early and late stages after wheel re-profiling do not exceed 2.5. The equivalent conicity increase is the main cause of bogie instability, and the bogie instability can be effectively suppressed by wheel re-profiling, replacing the yaw damper, and the rail grinding.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84934030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-14DOI: 10.1177/09544097231159707
Liepeng Ling, Feng Xue, Jianbo Zhang, Yi Huan, F. Chen
The detection of cracks in sleepers is important in ensuring safe operation of trains and the crack width is a key index in this process. The traditional YOLOv5 model can not achieve satisfactory detection results in the face of large changes in the scale of the target and interference of background information in the detection process. In this paper, a method to detect and measure the fine crack of sleeper based on improved YOLOv5 model of cascade fusion and edge fitting algorithm is proposed to solve these problems. An adaptive multi-scale feature fusion technique is proposed to achieve multi-scale feature fusion efficiently and solve the problem of large changes in the scale of the target. An improved method of feature recombination of attention mechanism is used to solve the interference problem of background information. On this basis, a method based on cascade fusion is proposed to fuse the above improvements and reconstruct the structure of the YOLOv5 model. Moreover, a fitting algorithm of the crack edge is proposed to realize the precise measurement of the maximum width of the fine crack on sleepers. Finally, the process of crack detection and width measurement of sleeper is developed and the performance of the method proposed in this paper is verified by experiments through self-made data sets. The experimental results show that the precision of crack detection is increased from 84.08% to 96.86%, and the recall is increased from 78.13% to 96.46%. The increases are 12.78% and 18.33% respectively. At the same time, the average detection time is reduced from 15.23 ms to 10.04 ms. The measurement accuracy of the maximum crack width is 0.05 mm.
{"title":"Intelligent detection of fine cracks on sleepers based on improved YOLOv5 model of cascade fusion","authors":"Liepeng Ling, Feng Xue, Jianbo Zhang, Yi Huan, F. Chen","doi":"10.1177/09544097231159707","DOIUrl":"https://doi.org/10.1177/09544097231159707","url":null,"abstract":"The detection of cracks in sleepers is important in ensuring safe operation of trains and the crack width is a key index in this process. The traditional YOLOv5 model can not achieve satisfactory detection results in the face of large changes in the scale of the target and interference of background information in the detection process. In this paper, a method to detect and measure the fine crack of sleeper based on improved YOLOv5 model of cascade fusion and edge fitting algorithm is proposed to solve these problems. An adaptive multi-scale feature fusion technique is proposed to achieve multi-scale feature fusion efficiently and solve the problem of large changes in the scale of the target. An improved method of feature recombination of attention mechanism is used to solve the interference problem of background information. On this basis, a method based on cascade fusion is proposed to fuse the above improvements and reconstruct the structure of the YOLOv5 model. Moreover, a fitting algorithm of the crack edge is proposed to realize the precise measurement of the maximum width of the fine crack on sleepers. Finally, the process of crack detection and width measurement of sleeper is developed and the performance of the method proposed in this paper is verified by experiments through self-made data sets. The experimental results show that the precision of crack detection is increased from 84.08% to 96.86%, and the recall is increased from 78.13% to 96.46%. The increases are 12.78% and 18.33% respectively. At the same time, the average detection time is reduced from 15.23 ms to 10.04 ms. The measurement accuracy of the maximum crack width is 0.05 mm.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90820756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-14DOI: 10.1177/09544097231162151
Hutang Sang, Jingsong Zeng, Yayun Qi, Caihong Huang, Jian Mu
Wheel wear prediction for high-speed railway vehicles during the acceleration process is of great importance for the improvement of operating characteristics and the development of friction management strategy near the railway station, especially in complex climatic environments. This work analyzes and predicts the wheel wear evolution of high-speed motor cars during acceleration. Firstly, detailed dynamic models of the high-speed motor car are developed, in which a comprehensive gear transmission system is also adopted to capture the accurate dynamic responses of the motor car. Secondly, the length of the simulated track interval with different friction coefficients is set according to the Gaussian distribution function to consider the influence of the friction coefficient. Moreover, a Proportional-Integral(PI) creep controller is also introduced to meet the challenge due to varying wheel-rail contact conditions, and a wheel wear prediction model based on the aforementioned submodels is established to obtain the wheel wear evolution. Finally, simulation results of dynamic responses from the vehicle dynamic model and wheel wear prediction procedure are compared with the measured field data. The results show that the time-varying meshing stiffness from the gear transmission system will aggravate the interaction between wheel and rail and deteriorate the wheel wear. When the high-speed motor car passes through a poor adhesion zone in the acceleration, it is easier to trigger the creep controller at the low-speed period while it will not occur at the high-speed period.
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