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6th International Conference on Energy Systems and Electrical Power, ICESEP 2024

作者： Ren, Guanzhou Xu, Shuai Ma, Guangtong Yao, Chunxing Southwest Jiaotong University State Key Laboratory of Rail Transit Vehicle System Chengdu China School of Electrical Engineering Southwest Jiaotong University Chengdu China

ISBN: (纸本)9798350353563

In high-speed train drive system, the maximum frequency is only a few hundred hertz due to the requirements of low switching loss and low junction temperature loss. Limited by the low switching frequency, multi-mode PWM modulation strategy is adopted in rail traction system and is difficult to transit smoothly among different modulation strategy. Because of SiC MOSFET have higher switching frequency and lower switching losses and other advantages, which can marvelously improve the switching frequency and power density of rail traction system. Moreover, Si/SiC hybrid active neutral point clamped (ANPC) inverter can optimize the loss distribution by adjusting the switching mode to improve the output power and efficiency. In this article, SiC devices and 3-level ANPC topology are introduced in rail traction system, and a simplified multi-mode modulation method is proposed based on that. The proposed scheme realizes high switching frequency, high efficiency and good tracking performance. Experimental results prove that the proposed simplified hybrid PWM scheme has good steady-state and dynamic performance in the full speed range. © 2024 IEEE.

关键词： Electric traction

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Piecewise model-based adaptive compensation control for high-speed trains with unknown actuator failures

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Transportation Safety and Environment 2023年第4期5卷 172-181页

作者： Chang Tan Junhui Zhang Hui Yang Leilei Zhang School of Electrical and Automation Engineering East China Jiaotong UniversityNanchangJiangxi 330013China State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure NanchangJiangxi 330013China

In order to deal with the uncertainties caused by different operation conditions and unknown actuator failures of high-speedtrains,an adaptive failures compensation control scheme is designed based on the piecewise model.A piecewise constant model is introduced to describe the variable system parameters caused by the variable operation environments,and a multiple-particle plecewise model of high-speed trains,with unknown actuator failures,is then *** adaptive failure compensation controller is developed for the multiple-particle piecewise constant model,by using a direct model refering to the adaptive control *** an adaptive controller can not only compensate the uncertainties from unknown actuator failures,but also effectively deal with the uncertainties caused by different operating ***,a CRH380A high-speed train model is taken as the controlled object for the simulation *** simulation results show that the proposed controller ensures the desired system performance in the presence of unknown actuator failures and uncertain operation conditions.

关键词： actuator failures adaptive compensation piecewise model high-speed train multiple-particle model

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A novel real-time arcing detection model of pantograph-catenary for high-speed train 3

A novel real-time arcing detection model of pantograph-caten...

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3rd International Conference on Electronics and Information Technology, EIT 2024

作者： Liu, Xiaolin Quan, Wei Hong, Peiyuan Zhou, Ning Southwest Jiaotong University School of Electrical Engineering Chengdu China Southwest Jiaotong University State Key Laboratory of Rail Transit Vehicle System Chengdu China

ISBN: (纸本)9798350369151

The arcing happened in Pantograph-catenary system could damage railway operation. Arcing are characterized by short and volatile durations, making it challenging to rapidly detect and segment arcing of varying shapes and sizes. To address these issues, a fast deep learning based semantic segmentation model named ECA-ArcSC is proposed for real-time arcing detecting and segmentation task. Firstly, four downsampling convolution layers are utilized to capture spatial information of the arcing. Concurrently, a four-stage downsampling strategy is employed to calculate contextual information of the arcing. Finally, the spatial and contextual information of the arcing is aggregated to predict the final dense semantic segmentation output. Experimental results on the Pantograph-catenary arcing dataset and comparative analysis demonstrate the effectiveness of the proposed approach, achieving IoU of 76.08% and Recall of 84.3%. For inputs of size 512×512, ECA-ArcSC achieves FPS of 123 on an NVIDIA 4070Ti graphics card. © 2024 IEEE.

关键词： Semantic Segmentation

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Automatic Modulation Classification Based on CNN, LSTM and Attention Mechanism 8

Automatic Modulation Classification Based on CNN, LSTM and A...

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8th IEEE International Conference on Computer and Communications, ICCC 2022

作者： Wang, Zewen Wang, Ping Lan, Pingying School of Information Science and Technology Southwest Jiaotong University Chengdu611756 China Fsdi State Key Laboratory of Rail Transit Engineering Informatization Xi'an710043 China

ISBN: (纸本)9781665450515

Automatic modulation recognition (AMR) is a key technology in the field of cognitive radio. To improve the performance, a new model for AMR, which incorporates an attention mechanism to extract the important features of the signal more effectively, is proposed in this paper. The simulation results show that our proposed method has a good recognition performance. In addition, our method can still achieve high accuracy, even if only a few samples are provided as the training set for training. We also visualize the output features of the model and show the positive effect of the attention mechanism on signal modulation category identification. © 2022 IEEE.

关键词： Cognitive radio

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Effect of Yaw Damper on Different Hunting Motions of High-Speed Trains under Various Vehicle Configurations 3

Effect of Yaw Damper on Different Hunting Motions of High-Sp...

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3rd International Conference on rail Transportation, ICRT 2024

作者： Isacchi, Gioele Shi, Huailong Ripamonti, Francesco Zeng, Jing Dept. of Mechanical Engineering Politecnico di Milano Milano Italy State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong Univ. Chengdu China

ISBN: (数字)9780784485941

ISBN: (纸本)9780784485941

Stability and ride comfort are fundamental features of high-speed rail vehicles. The first must be assured to guarantee a safe ride, the second is important to offer a comfortable experience to the passengers. Yaw dampers proved to significantly influence both the vehicle stability and the ride comfort. Nevertheless, it is not trivial to optimize the damper layout to face different wheel/rail and operating conditions. In this context, this paper presents a numerical methodology to assess the influence of different yaw damper layouts on the vehicle stability, with a special focus on both carbody and bogie hunting motions. Different combinations of yaw damper layout, equivalent conicity, vehicle speed, primary longitudinal stiffness, and environmental conditions will be tested. The effect of the yaw damper on the arising of different kind of unstable motions will be assessed, and the main unstable phenomena will be presented by comparing their damped frequency and mode shapes. Finally, a stable region describing the layout of yaw dampers able to guarantee stable running conditions will be defined, highlighting the limits of standard passive solutions. © ASCE.

关键词： railroads

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How to improve superlubricity performance of diketone at steel interface:Effects of oxygen gas

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Friction 2023年第6期11卷 927-937页

作者： Yuanyuan JIANG Lei CHEN Chen XIAO Shumin ZHANG Chenhui ZHANG Ningning ZHOU Tao QIN Linmao QIAN Jiyang ZHANG Tribology Research Institute State Key Laboratory of Traction PowerSouthwest Jiaotong UniversityChengdu610031China Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province Southwest Jiaotong UniversityChengdu610031China State Key Laboratory of Tribology Tsinghua UniversityBeijing100084China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing100094China

Achievement of steady and reliable super-low friction at the steel/steel contact interface,one of the most tribological systems applied for mechanical moving parts,is of importance for prolonging machine lifetime and reducing energy *** we reported that the superlubricity performance of the steel/steel sliding interface lubricated with tiny amounts of diketone solution strongly depends on the oxygen content in surrounding *** increase of oxygen not only significantly shortens the initial running-in time but also further reduces the stable coefficient of friction in superlubricity stage due to the enhancement of tribochemical *** the one hand,more severe oxidation wear occurring at higher oxygen content facilitates material removal of the contact interface,lowering the contact pressure and the corresponding initial *** the other hand,the growth of iron ions during the shear process in high oxygen environment promotes the formation of chelate which acted as an effective lubricated film chemisorbed at the steel/steel friction interface to further lower the interfacial *** results provide a new opportunity to further optimize the tribological performance of diketone superlubricity system,especially towards the lubrication of mechanical engineering materials.

关键词： superlubricity oxygen content steel/steel interface diketone chelate

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High-performance wearable bimetallic nanowire-assisted composite foams for efficient electromagnetic interference shielding,infrared stealth,and piezoresistive sensing

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Nano Research 2024年第7期17卷 6757-6765页

作者： Tianyi Hang Lijie Zhou Chenhui Xu Yiming Chen Jiahui Shen Jiajia Zheng Pingan Yang Xiping Li Heng Luo Guoxiu Tong Key Laboratory of Urban Rail Transit Intelligent Operation and Maintenance Technology and Equipment of Zhejiang Province College of EngineeringZhejiang Normal UniversityJinhua 321004China School of Automation Chongqing University of Posts and TelecommunicationsChongqing 400065China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Key Laboratory of the Ministry of Education for Advanced Catalysis Materials College of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua 321004China

With the accelerated development of modern detection and communication technology,the multifunctional wearable materials with excellent electromagnetic interference(EMI)shielding,infrared stealth,and human monitoring for improving military combat capability have received extensive *** this work,the lightweight melamine foam(MF)@silver nanowires(AgNWs)-iron nanowires(FeNWs)(AgFe-MF)was fabricated by a vacuum-assisted dip-coating *** to the porous structure and synergistic electrical and magnetic losses,this lightweight(0.115 g/cm^(3))composite foam with an ultra-low filler content(0.62 vol.%)exhibited an ideal EMI shielding efficiency of 38.4 *** the other hand,the AgFe-MF realized a powerful multifunctional *** surface saturation temperature of the AgFe-MF reached 94.2℃under a low applied voltage of 1.8 V and remained extremely fast heating and cooling response and terrific working stability,resulting in excellent infrared stealth and camouflage ***,taking virtues of the elastic porous conductive architecture,the AgFe-MF was utilized as a piezoresistive sensor exhibiting board compressive interval of 0–1.62 kPa(50%strain)with a good sensitivity of 0.57 kPa^(−1).This work will provide new ideas and insights for developing multifunctional wearable devices in the fields of EMI shielding,thermal management,and piezoresistive sensing.

关键词： metal nanowires porous foams electromagnetic interference shielding infrared stealth wearable sensors

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An Investigation on the Influence of Multi-damage of Bearings on Axle Box Vibration for railway Vehicle

An Investigation on the Influence of Multi-damage of Bearing...

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UNIfied Conference of International Workshop on Defence Applications of Multi-Agent Systems, DAMAS 2023, International Conference on Maintenance engineering, IncoME-V 2023, International conference on the Efficiency and Performance engineering Network, TEPEN 2023

作者： Yi, Cai Wang, Jingyuan Lin, Jianhui Zhang, Weihua Liao, Xiaokang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu610000 China School of Mechanical Engineering Xihua University Chengdu610000 China

ISBN: (纸本)9783031494123

As one of the most important parts of the high-speed train rotation system, the axle box bearing mainly supports the rotation of the system and provides additional damping to make the system operate stably. Axle box bearing, as the key to transfer traction power, is susceptible to the excitation caused by the complex status of wheelset. In particular, wheelset is disturbed by wheel-rail wear, wheel polygon and operation line environment, which leads to dynamic uncertainty of its excitation. This makes the vibration response of axle box bearing more complicated. The vibration characteristics and characteristic evolution rule of axle box bearings change with the excitation action, which makes it difficult to monitor, identify and predict the health status of the axle box system. Based on the multi-body dynamics software, the axle box system-vehicle-track coupling dynamics model containing bearing outer race faults and roller faults is established. In view of the local defects and faults of axle box bearings that often occur in the service process of high-speed trains, that is, outer race faults and roller faults as model excitation, the safety threshold of corresponding defects is given by analyzing the influence of different defect widths of outer race and roller for axle box bearing and the influence of compound defect excitation for bearing outer race and wheel flat scar on vibration characteristics of axle box system, which provides the foundation for the health monitoring of axle box system. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： railroads

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A Text Classification Method of Network Public Opinion Based on Information Fusion

A Text Classification Method of Network Public Opinion Based...

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2023 International Conference on Networking and Network Applications, NaNA 2023

作者： Zhu, Lei Wen, Miaoqing Zhang, Tong Wang, Yichuan Wang, Jing Yang, Mingsong Ma, Bing State Key Laboratory of Rail Transit Engineering Information Fsdi Xi'an China School of Computer Science and Engineering Xi'an University of Technology Xi'an China

ISBN: (纸本)9798350327380

With the widespread use of mobile networks and intelligent terminal devices, a large amount of public opinion text has been generated from Microblogs, posting bars, and other platforms, resulting in the difficulty of public opinion management. More and more researchers use text classification methods to identify law-related public opinion information. However, the existing text classification methods rely on labor-intensive feature engineering, and their performance mainly depends on information fusion and classification algorithms, which is unsuitable for rapidly developing fields. This paper extracts the user comments of a hunting forum to analyze the semantic information of argot and employs the Word2vec model to represent the argot feature. Combining the multi-layer information of the pre-trained BERT on the user comments, we propose a text classification method BERT_W2V_CRF to improve the classification efficiency of massive law-related public opinion texts. Specifically, we first build a terminology dictionary of Chinese hunting forum to identify the argot features in expert-marked data using the Word2vec model. Then the BERT model is pretrained and the representation of fused information is generated by combining the Word2vec and optimized BERT. Finally, the recognized result is obtained by using Softmax. Experiments are conducted on the user comment dataset to evaluate the proposed text classification method, and the results show that the information fusion approach can be used to improve the classification efficiency of the deep learning-based method. © 2023 IEEE.

关键词： Semantics

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Helical streamers guided by surface electromagnetic standing waves

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Plasma Science and Technology 2023年第7期25卷 1-5页

作者：邹丹旦涂忱胜崔春梅 State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang 330013Peopleʼs Republic of China School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072Peopleʼs Republic of China

The streamer that is driven by the specific pulse DC discharge parameters can stably form a three-dimensional helical plasma channel in a long dielectric tube in the low-temperature plasma experiment,in cases when there were neither external background magnetic field or other factors that destroyed the poloidal symmetry of the *** formation mechanism and chirality of helical streamers are discussed according to the surface electromagnetic standing wave *** shape of the helical streamers and the characteristics of helical branches are quantitatively analyzed to further expand the application of plasma and streamer theory in the helix problem and chiral catalytic synthesis.

关键词： low-temperature plasma streamers surface electromagnetic standing wave helix

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