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Directional Beamforming for High-Speed Railway Communications with Frequency Offset Precorrection

Chinese Journal of Electronics 2025年第1期23卷 163-168页

作者： Yuan Cao Yinghong Wen Wei Xu Xin Xie School of Electronics and Information Engineering Beijing Jiaotong University National Engineering Research Center of Rail Transportation Operation and Control System Beijing China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing China National Mobile Communications Research Lab. Southeast University Nanjing China

This paper considers a multi-antenna transmission strategy for high speed railway communications. In order to achieve better performance than conventional space-frequency block coding schemes, we propose a directional beamforming strategy for the High-speed railway (HSR) communication by exploiting some characteristic of the railway system including predetermined moving tracks and real-time positioning information. Moreover, for alleviating the effect of Doppler shift due to the moving train, a frequency offset precorrection method is also incorporated with direction beamforming. Theoretical Signal-to-noise ratio (SNR) gain of the proposed beamforming scheme over traditional HSR communication schemes is also derived for illustrating the performance enhancement. Numerical results verify the effectiveness of our proposed scheme even with some kind of imperfect position information available at the transmitter.

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Energy harvesting and speed sensing with a hybrid rotary generator for self-powered wireless monitoring

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Acta Mechanica Sinica 2024年第9期40卷 116-130页

作者： Zhixia Wang Hongyun Qiu Xuanbo Jiao Wei Wang Qichang Zhang Ruilan Tian Dongxing Cao School of Mechanical Engineering Tianjin UniversityTianjin 300350China Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin 300350China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Mechanics Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

Real-time onboard health monitoring systems are critical for the railway industry to maintain high service quality and operational ***,the issue with power supplies for monitoring sensors persists,especially for freight trains that lack onboard ***,we propose a hybrid piezoelectric-triboelectric rotary generator(HPT-RG)for energy harvesting and vehicle speed *** HPT-RG incorporates a rotational self-adaptive technique that softens the equivalent stiffness,enabling the piezoelectric non-resonant beam to surpass resonance limitations in a low-frequency *** experiments demonstrate the feasibility of using the HPT-RG as an energy harvesting module to collect the rotational energy of the freight rail transport and power the wireless temperature *** allow multiple monitoring in confined spaces on trains,a triboelectric sensing module is added to the HPT-RG to sense the operation speed and mileage of ***,the generator exhibits favorable mechanical durability under more than 600 h of official testing on the train bogie *** proposed HPT-RG is essential for creating a truly self-powered,maintenance-free,and zero-carbon onboard wireless monitoring system on freight railways.

关键词： Energy harvesting Speed sensing Rotational self-adaptive technique Low-frequency Self-powered wireless monitoring

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A NOVEL BEARING FAULT DIAGNOSIS METHOD BASED ON FEATURE FUSION AND CONVOLUTIONAL NEURAL NETWORK 1

A NOVEL BEARING FAULT DIAGNOSIS METHOD BASED ON FEATURE FUSI...

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1st International Conference on Mechanical system Dynamics, ICMSD 2022

作者： Zhao, Jing Yang, Shaopu Li, Qiang Liu, Yongqiang School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (数字)9781839537837

ISBN: (纸本)9781839537837

The effective fault diagnosis method is crucial for the engineering. At present, the fault diagnosis methods based on data-driven have achieved much attention. The traditional methods only utilize one sensor or one channel data. However, there are more than one sensor or channel in the data acquisition system. To take full advantage of the connection between different channels data, a bearing fault diagnosis method based on feature fusion and convolutional neural network is put forward in this paper. First, two different channels data are fused to obtain different fault features. Then, convolutional neural network is applied to classify the different faults through the fusion features. Finally, the performance of the proposed approach is verified by the drive train dynamics simulator test. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Failure analysis

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EFFECT OF TOOTH CRACK ON MESH STIFFNESS AND VIBRATION RESPONSE OF A SPUR GEAR system WITH CLEARANCE NONLINEARITY 1

EFFECT OF TOOTH CRACK ON MESH STIFFNESS AND VIBRATION RESPON...

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1st International Conference on Mechanical system Dynamics, ICMSD 2022

作者： Hou, Jingyu Li, Qiang Yang, Shaopu Liu, Yongqiang School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (数字)9781839537837

ISBN: (纸本)9781839537837

The mesh stiffness and vibration characteristics of a spur gear system are investigated when the crack propagates beyond the central line of the tooth. The time-varying mesh stiffness (TVMS) in the single-tooth engagement region and in the double-tooth engagement region for a spur gear with tooth crack is obtained based on the potential energy principle. A 4 DOF gear system considering the tooth backlash and the clearance of supporting system in the radial direction is established, and the effect of different crack sizes on the response of the system is studied. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Spur gears

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Performance simulation analysis of new train control system safety communication protocol based on Matlab/SimEvents 5

Performance simulation analysis of new train control system ...

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2022 5th International Conference on Power Electronics and control engineering, ICPECE 2022

作者： Jing, Zhiqiang Li, Kaicheng Wei, Guodong Liu, Yu School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China Collaborative Innovation Center of Railway Traffic Safety National Engineering Research Center of Rail Transit Operation Control System Beijing Jiaotong University Beijing100044 China

The vehicle-ground safety communication of the New Train control system adopts a brand-new underlying network and a communication mechanism of safe and reliable transmission. Based on the GPRS packet switching network, the data link layer adopts the PPP protocol, and the TCP protocol is adopted in the transmission layer to provide reliable transmission services. According to the GPRS network service quality index and the retransmission mechanism of the TCP protocol in the transport layer, this paper adopts the Matlab/SimEvents discrete event simulation method and uses the entity as the communication carrier to conduct a hierarchical and modular system-level modeling of New Train control system vehicle-ground communication protocol. It simulates the communication process of the message from the application layer, the security layer to the transport layer, and finally transmitted on the GPRS network channel with random delay and packet loss probability. From the quantitative point of view, this paper analyzes the safety connection establishment time and success rate of the new train control system vehicle-ground wireless communication under different channel conditions, the timeliness of the non-periodic message receiving a reply to complete the specific scene function, and the reliability of the periodic message receiving delay. The analysis results show that the new train control system vehicle-ground wireless communication adopts GPRS network and TCP protocol retransmission mechanism to improve the real-time and reliability of communication. © Published under licence by IOP Publishing Ltd.

关键词： MATLAB

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Design and Wave Propagation Characterization of Starchiral Metamaterials

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Acta Mechanica Solida Sinica 2022年第2期35卷 215-227页

作者： Yajun Xin Han Wang Cong Wang Jinxin Yao Qian Ding Haoqiang Gao Shuliang Cheng Yongtao Sun Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province Yanshan UniversityQinhuangdao 060000China Hebei Province Low-Carbon and Clean Building Heating Technology Innovation Center Yanshan UniversityQinhuangdao 060000China Department of Mechanics and Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin UniversityTianjin 300072China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Metamaterials with simple artificial topological properties made from industrially produced single-phase materials have extraordinary innovation and *** this paper,we investigated wave propagation characteristics of a hexastarchiral lattice metamaterial with periodic assemblies and used the finite element(FE)method to study the band gap ***,in order to understand the mechanism of band gaps,we discussed the mode shapes of unit cells and found that the bending of the ligament and the overall rotation have a high correlation with the generation of omnidirectional band *** relationships bet ween geometric parameters and band gap properties have also been systematically studied,which demonstrated that the band gaps of the proposed metamaterial could be reasonably predicted through the evolution of geometric ***,the transmission characteristics of finite sandwich panel structures composed of periodic unit cells were calculated to verify the correctness of the band gap simulation results,which proved that the proposed artificial metastructure has potential application value in vibration and noise reduction projects.

关键词： Hexastarchiral lattice metamaterials Band gap properties Finite element method Rotational resonance

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A Novel Millimeter-Wave Channel Measurement Platform for 6G Intelligent Railway Scenarios

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China Communications 2022年第11期19卷 60-73页

作者： Dan Fei Chen Chen Peng Zheng Dongsheng Zhang Jingya Yang Haoran Chen Bo Ai School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China Collaborative Innovation Center of Railway Traffic Safety Beijing Jiaotong UniversityBeijing 100044China Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong UniversityBeijing 100044China Zhengzhou Railway Vocational and Technical College Zhengzhou 451460China Peng Cheng Laboratory Shenzhen 518055China

This paper presented a novel millimeterwave channel measurement platform for the 6G intelligent *** platform used phased array antenna with 64 elements and can support instant bandwidth up to 1 *** with improved multi-tone sounding signals,the platform can enhance dynamic measurement capability in high-speed railway *** performed calibration works about frequency flatness,frequency offset and proved platform reliability with channel emulator based closed-loop *** also carried out field trials in high-speed railway carriage *** on measurement results,we extracted channel characteristic parameters of path loss,power delay profile and delay spread to further verify the field measurement performance of the platform.

关键词： 6G millimeter-wave channel measurement phased array antenna high-speed railway

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Uav anti-collision visual detection algorithm

Uav anti-collision visual detection algorithm

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Computer Vision, Image and Deep Learning (CVIDL), International Conference on

作者： Jun Yu Han Zhe Li Sheng Hou Li Bo Shen Zhao Air Traffic Control and Navigation School Air Force Engineering University Xi'an Key Laboratory of Meta-Synthesis for Electornic and Information System Xi'an China

In order to solve the problem of unsafe flight of traditional “low, slow and small” civil UAVs, and reduce pres sure on air traffic control personnel., an improved YOLOv5m target detection algorithm is proposed for active target detection of UAVs. According to the characteristics of low-altitude UAV detection, an attention mechanism was added to the YO LOv5 feature extraction network, and the original weighted NMS was optimized to SOFT_NMS Finally, the accuracy and real-time performance of the model are verified by constructi ng real UAV conflict target detection data set. The experimen tal results show that the average accuracy, recall rate, accura cy are 2.31 %, 3.66% and 5.59% higher than before the impr ovement, meet the anti-collision detection requirements of civi 1 UAV s in low altitude airspace.

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KLT-Based Estimation of Equivalent Channels in 5G MIMO systems 8

KLT-Based Estimation of Equivalent Channels in 5G MIMO Syste...

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

作者： Yang, Zexuan Liu, Yinsheng School of Electronic and Information Engineering Beijing Jiaotong University Beijing China State Key Laboratory of Rail Traffic Control and Safety Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University Beijing China

ISBN: (纸本)9781665450515

To enable large number of antennas in massive multi-input multi-output (MIMO) systems, demodulation reference signal (DM-RS) has been widely used for accurate channel estimation in mobile systems. As DM-RS and data symbols go through the same precoding matrix before sent to channel, channel estimation based on DM-RS is actually conducted with respect to an equivalent channel, which is a combination of the precoding matrix and the physical channel. As a consequence, channel estimation has to be conducted within the frequency range of one precoding resource group (PRG), because a different precoding matrix may be used for neighbouring PRGs. In this paper, by observing that the channel frequency responses in different PRGs can share the same bases, a Karhunen-Loève Transform (KLT) based channel estimation approach is proposed. Using this approach, received signals from adjacent PRGs can be exploited to improve the quality of channel estimation for the PRG of interest. Simulation results show that the channel estimation mean square error (MSE) of our method is better than that of the Toeplitz correction by more than 3dB. Moreover, by adopting this novel channel estimation approach, the performance of symbol error ratio (SER) is close that using ideal channel estimation results. © 2022 IEEE.

关键词： Channel estimation

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An Improved Safe Braking Model of Virtually Coupled Trains for Closer Tracking 21

An Improved Safe Braking Model of Virtually Coupled Trains f...

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21st International Conference on Networking, Sensing and control, ICNSC 2024

作者： Yan, Wenxiao Wang, Jiayu Fan, Liqun Liu, Qiusheng Jia, Qingdong Wang, Yihan Liu, Hongjie Shenzhen Metro Group Co. Ltd. Shenzhen518026 China Shenzhen Municipal Design and Research Institute Co. Ltd. Shenzhen518029 China Traffic control Technology Co. Ltd. Beijing100070 China School of Automation and Intelligence Beijing Jiaotong University Beijing100044 China Beijing Jiaotong University National Engineering Research Center of Rail Transportation Operation and Control System Beijing100044 China

ISBN: (纸本)9798350365221

With the rapid growth of transportation passenger flow in recent years, the research direction of Virtual Coupling (V C) in railways has become hot. V C increases capacity by tracking shorter distances. The traditional train emergency braking (EB) model can no longer meet the high operating efficiency requirements of VC. VC urgently needs a more efficient safety EB model. Therefore, to improve efficiency, a measurement of the EB model's rationality is defined considering safety and efficiency. Based on the defined model measurement, an EB model optimization method and a new EB model are proposed. The new model is closer to the actual braking process of the train and ensures safety from the distance level. That is, the braking trajectory of the train calculated by the new model is closer to the actual braking trajectory of the train, and the two braking trajectories satisfy the specific safety constraints. Finally, the safety and efficiency of the new model were verified through simulation experiments. The new model can avoid train collisions during the entire EB process. Experimental results show that compared with the traditional old EB model of VC based on space-time interval [1], the new model's minimum safe distance (MSD) between two VC train units can be reduced by 39%. © 2024 IEEE.

关键词： Railroad accidents

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