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3rd International Conference on Rail Transportation, ICRT 2024

作者： Zhou, Ziwei Ye, Zirui Chen, Zaigang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong Univ. Chengdu China Faculty of Transportation Engineering Kunming Univ. of Science and Technology Kunming China

ISBN: (数字)9780784485941

ISBN: (纸本)9780784485941

This paper investigates the dynamics and wear characteristics of bearings in a locomotive's traction transmission system, emphasizing the electromechanical coupling effects. A comprehensive locomotive-track coupled dynamics model, integrating electrical and mechanical subsystems, is utilized to simulate the behavior under typical operational conditions without considering track irregularities. The study introduces a wear model based on Archard's theory, applied to cylindrical roller bearings, which quantifies wear evolution via dynamic contact parameters and stress distributions. Simulations at 80 km/h reveal significant wear differences between models with and without electromechanical coupling, underscoring the impact of such coupling on bearing durability and locomotive performance. The findings illustrate that electromechanical interactions exacerbate wear, particularly on the driving end, and suggest that incorporating these factors can lead to more accurate predictions of bearing lifespan and maintenance scheduling. © ASCE.

关键词： Roller bearings

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Counter-Reconnaissance Performance Analysis Of Amplitude Coded Modulation Radar Waveform

Counter-Reconnaissance Performance Analysis Of Amplitude Cod...

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IET International Radar Conference 2023, IRC 2023

作者： Liu, Zhenyu Liu, Xiaobin Wu, Qihua Zhao, Feng Xu, Zhiming Xiao, Shunping The State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and Technology National University of Defense Technology ChangSha China

ISBN: (纸本)9781839539954

The electronic reconnaissance systems can obtain intelligence information from technical parameters of radiation sources. Then, anti-radiation missiles can be used to destroy radiation sources, seriously threatening the survival of radar systems. To improve radar counter-reconnaissance capability, various waveforms are proposed. Among the waveforms, amplitude coded modulation (ACM) can divide the pulse into many short pulses. The signal sorting may fail so that the signal is difficult to be recognized. Therefore, the ACM signal can improve the counter-reconnaissance performance. However, the signal counter-reconnaissance performance has not been discussed. Thus, the uniform and non- periodic ACM model are proposed in this paper. Time-frequency distribution entropy and intercept probability of ACM signal are utilized to evaluate the counter-reconnaissance performance. Simulations are conducted to verify the accuracy of theoretical analysis. © The Institution of Engineering & technology 2023.

关键词： Signal modulation

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Wearable multichannel pulse condition monitoring system based on flexible pressure sensor arrays

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Microsystems & Nanoengineering 2022年第1期8卷 249-258页

作者： Jie Wang Yirun Zhu Zhiyong Wu Yunlin Zhang Jian Lin Tao Chen Huicong Liu Fengxia Wang Lining Sun Jiangsu Provincial Key Laboratory of Advanced Robotics School of Mechanical and Electric EngineeringSoochow UniversitySuzhou 215123China Micro Nano System Research Center Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education and Shanxi Province&College of Information EngineeringTaiyuan University of TechnologyTaiyuan 030024China Suzhou Institute of Nano-tech and Nanobionics Chinese Academy of SciencesSuzhou 215123China

Pulse diagnosis is an irreplaceable part of traditional Chinese medical ***,application of the traditional pulse monitoring method was restricted in the modernization of Chinese medical science since it was difficult to capture real signals and integrate obscure feelings with a modern data ***,a novel multichannel pulse monitoring platform based on traditional Chinese medical science pulse theory and wearable electronics was *** pulse sensing platform simultaneously detected pulse conditions at three pulse positions(Chi,Cun,and Guan).These signals were fitted to smooth surfaces to enable 3-dimensional pulse mapping,which vividly revealed the shape of the pulse length and width and compensated for the shortcomings of traditional single-point pulse ***,the pulse sensing system could measure the pulse signals from different individuals with different conditions and distinguish the differences in pulse *** addition,this system could provide full information on the temporal and spatial dimensions of a person’s pulse waveform,which is similar to the true feelings of doctors’*** innovative,cost-effective,easily designed pulse monitoring platform based on flexible pressure sensor arrays may provide novel applications in modernization of Chinese medical science or intelligent health care.

关键词： multichannel system replace

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Waveform Design for Pulse Radar Based on Interrupted Coding Modulation

Waveform Design for Pulse Radar Based on Interrupted Coding ...

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IET International Radar Conference 2023, IRC 2023

作者： Liu, Xiaobin Wu, Qihua Gu, Zhaoyu Liu, Zhenyu Zhao, Feng Xiao, Shunping The State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and Technology National University of Defense Technology ChangSha China

ISBN: (纸本)9781839539954

Coding modulation is utilized to design radar waveform to obtain complex properties so that the waveform is difficult to be recognized. However, traditional coding modulation brings high sidelobe in target range profile which makes the detection performance decrease. To solve this problem, the interrupted coding modulation is proposed in this paper based on the interrupted transmitting and receiving. The signal model is provided and the low sidelobe property of range profile is discussed. Constant false-alarm rate (CFAR) is utilized to evaluate the detection performance of interrupted coding modulation waveform. Simulations are conducted to verify the low sidelobe property and detection performance of the proposed waveform. © The Institution of Engineering & technology 2023.

关键词： Signal modulation

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Depositing the PtNi nanoparticles on niobium oxide to enhance the activity and CO-tolerance for alkaline methanol electrooxidation

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Chinese Journal of Structural Chemistry 2023年第11期42卷 25-31页

作者： Xinyi Hu Riguang Zhang Zhao Jiang Department of Chemical Engineering Shaanxi Key Laboratory of Energy Chemical Process IntensificationEngineering Research Center of New Energy System Engineering and Equipment Xi'an Jiaotong UniversityXi'an710049China State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan030000China

Direct methanol fuel cells have the advantages of simple system,convenient operation,high conversion rate and low carbon emission,which are considered as the environmental and friendly energy conversion ***-ever,the low activity,CO-tolerance and high cost of anode catalysts restrict the large-scale commercial ***,it is of great practical significance to design and construct the anodic catalysts with high activity,stability and low cost for methanol oxidation *** this work,the PtM/Nb_(2)O_(5)-C(M=Co,Sn,Ni)catalysts are synthesized by the ethylene glycol solvothermal method using transition metal oxide Nb_(2)O_(5)as the *** catalytic performance of different catalysts is further evaluated for alkaline *** results show that the introduction of Ni(existing in Ni^(2+)and Ni^(3+))has the most obvious improvement for alkaline MOR *** adjusting the doped ratio of Pt:Ni,it is shown that PtNi/Nb_(2)O_(5)-C has the highest mass activity(3877.9 mA-mg_(pt)^(-1)),12 times that of the commercial Pt/C ***,LSV,Tafel and EIS analyses show that PtNi/Nb_(2)O_(5)-C has the lowest onset potential and charge transfer resistance,and the fastest electrocatalytic oxidation rate of *** tests show that the electrochemical stability is also significantly improved with the introduction of Nb_(2)O_(5)and *** with the structural characterization and electrochemical tests,it is found that the evident electronic effect among Pt and Ni,Nb_(2)O_(5)and the hydroxyl brought from Ni species are mainly ascribed for enhancing the activity,CO resistance and stability of PtNi/Nb_(2)O_(5)-C.

关键词： Direct methanol fuel cell Niobium oxide Platinum-based catalysts Methanol oxidation reaction

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CHARACTERISTICS ANALYSIS OF STEPPED FREQUENCY CHIRP SIGNAL USING UNIFORM INTERRUPTED MODULATION

CHARACTERISTICS ANALYSIS OF STEPPED FREQUENCY CHIRP SIGNAL U...

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IET International Radar Conference 2023, IRC 2023

作者： Zhao, Tiehua Wu, Qihua Xu, Zhiming Zhao, Feng Xiao, Shunping The State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and Technology National University of Defense Technology Changsha China

ISBN: (纸本)9781839539954

The co-modulation is beneficial for increasing the anti-reconnaissance potential of radar waveform. Stepped frequency chirp (SFC) signal has the characteristics of both linear frequency modulation (LFM) signal and stepped-frequency waveform (SFW). Uniform interrupted modulation (UIM) can increase the complexity of the signal in the time domain. Therefore, the characteristics of the SFC signal with UIM are deduced in this paper. First of all, the processing method of the SFC signal is introduced. Then the characteristics of the SFC signal with UIM are analysed emphatically. The high-resolution range profile (HRRP) of the inter-pulse and intra-pulse interrupted modulation are both deduced respectively. It is concluded that the UIM between pulses brings the HRRP of the SFC signal multiple pseudo peaks extending along the range profile. However, there is no pseudo peak in the HRRP of the intra-pulse interruptedly modulated SFC signal. Signal simulation experiments are carried out with MATLAB to verify the accuracy of the theoretical analysis. © The Institution of Engineering & technology 2023.

关键词： Chirp modulation

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Ladder Time Stepwise Inertia Coordinated Control Method of Multiple Wind Farms to Suppress system Frequency Secondary Drop

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Energy Engineering 2024年第8期121卷 2293-2311页

作者： He Li Xianchao Liu Jidong Li Yuchen Qiu Tongliao PowerSupply Company State Grid East Inner Mongolia Electric Power CompanyTongliao028000China Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology Northeast Electric Power UniversityJilin132012China

Currently,both regulated and deregulated power trading exist in China’s power system,which has caused imbalanced funds in the electricity *** this paper,a simulation analysis of the electricity market with wind energy resources is conducted,and the calculation methods of unbalanced funds are investigated *** detail,the calculation formulas of unbalanced funds are illustrated based on their definition,and a two-track electricity market clearing model is ***,the concept of the dual-track system is explained,and the specific calculation formulas of various types of unbalanced funds are ***,considering the renewable energy consumption,the market clearing model based on DC power flow is constructed and solved;by combining fitting methods of mid-and long-term curves,the unbalanced funds are calculated based on clearing results and formulas.

关键词： Wind power stepwise inertial frequency control secondary drop

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Rapid Re-Convergence of Real-Time Dynamic Precise Point Positioning by Adding Velocity Constraints

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Gyroscopy and Navigation 2022年第4期13卷 283-293页

作者： Xingxing Wang Sheng, Chuanzhen Yu, Baoguo Zhang, Ziteng Zhang, Jingkui Yi, Qingwu State Key Laboratory of Satellite Navigation System and Equipment Technology Shijiazhuang China The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang China

Abstract—: In challenging environments like urban vehicle navigation and geological hazards, the GNSS signals are easily blocked, and the long re-convergence time seriously limits many applications of real-time dynamic precise point positioning. Considering that the velocity accuracy is better than the position during re-convergence epochs, we proposed a real-time rapid-positioning method by introducing velocity constraints into the dynamic PPP. According to the different motion states and environments, different velocity constraints are used adaptively. For example, the zero-velocity constraint model is used in the stationary state;the Doppler-velocity constraint model is used when the most visible satellites are temporarily blocked;the other-sensors-velocity constraint model is used when the satellite signal is blocked frequently. Considering that the inaccurate dynamic model will affect the dynamic positioning results, the velocity constraint can be gradually relaxed after the GNSS signals are reacquired and the ambiguity gradually converges. Based on static and kinematic experiments with GPS data, the results show that when the number of visible satellites is greatly dropped due to signal blocking, the new positioning method can significantly speed up the re-convergence of precise point positioning, maintain high accuracy and improve the continuity of real-time dynamic positioning in a short time. © 2022, Pleiades Publishing, Ltd.

关键词： Satellites

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Stabilization of Perturbed Continuous-Time systems Using Event-Triggered Model Predictive Control

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IEEE Transactions on Cybernetics 2022年第5期52卷 4039-4051页

作者： Wang, Mengzhi Sun, Jian Chen, Jie Zhejiang University State Key Laboratory of Industrial Control Technology Hangzhou310027 China Beijing Institute of Technology Key Laboratory of Intelligent Control and Decision of Complex System Beijing100081 China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120 China

In this article, event-triggered model predictive control (EMPC) of continuous-time nonlinear systems with bounded disturbances is studied. Two novel event-triggered control schemes are proposed. In the first strategy, an event-triggering condition, designed based on the state error between the actual system state and the optimal one, with an absolute threshold is considered. In the second strategy, an event-triggering condition with a mixed threshold is designed to further save the computational resources. The minimal interevent times of both event-triggered control schemes are obtained to avoid the Zeno behavior. Sufficient conditions of recursive feasibility for these two triggering strategies, which refer to the prediction horizon, the triggering level, and the disturbance bound, are obtained, respectively. Input-to-state practical stability (ISpS) of both event-triggered control systems is established without requiring the system state entering the terminal set in finite time, respectively. Finally, the numerical simulation shows the effectiveness of the proposed methods. © 2013 IEEE.

关键词： Model predictive control

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Anechoic Chamber Equivalent Simulation Method for Intermittent Transceiver Echo Based on Space Target Electromagnetic Scattering Data

Anechoic Chamber Equivalent Simulation Method for Intermitte...

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IET International Radar Conference 2023, IRC 2023

作者： Qiao, Zhenyu Liu, Xiaobin Xie, Ailun Wu, Qihua Zhao, Feng Wang, Ling The State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and Technology National University of Defense Technology Changsha China

ISBN: (纸本)9781839539954

Electromagnetic simulations and anechoic chamber measurements are commonly used to obtain target characteristics. The use of intermittent transceiver in anechoic chamber can effectively solve the problem of the signal coupling at the receiver. However, the method of equivalent simulation between electromagnetic simulation and intermittent transceiver is rarely discussed. In this paper, an intermittent transceiver echo equivalent simulation method in anechoic chamber is proposed based on space electromagnetic scattering data. Then, the characteristics of scattering points of targets under micro-motion conditions are analyzed. Finally, the equivalent relationship and processing flow between electromagnetic scattering data and intermittent transceiver echo are discussed. Simulations are conducted to verify the effectiveness of the proposed method. © The Institution of Engineering & technology 2023.

关键词： Anechoic chambers

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