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2024 IEEE International Conference on Sensing, Diagnostics, Prognostics, and Control, SDPC 2024

作者： Guo, Jinying Shi, Huailong Wu, Pingbo Zhang, Dapeng School of Automation Chengdu University of Information Technology Chengdu China Southwest Jiaotong University State Key Laboratory of Rail Transit Vehicle System Chengdu China

ISBN: (纸本)9798350388855

Hunting stability is the foundation of the dynamic performance of high-speed trains. Due to factors such as track irregularities, the evolution of wheel-rail relationships, and degradation of vehicle suspension parameters, small-amplitude bogie hunting (SABH)was discovered in the line test of high-speed trains. To meet the higher requirements of existing high-speed trains and standard EMUs for vehicle dynamic performance, it is necessary to study the accurate and rapid identification method for SABH. The distribution differences of vibration characteristics between normal and SABH samples were compared using the Wasserstein distance. Power spectral entropy (PSE) and wavelet energy ratio (WER) have the farthest Wasserstein distance. The importance of features was ranked using MRMR and Rrelief, and the classification importance score of the autocorrelation coefficient (ACC) was the highest. Comparing the application effects of different machine learning methods in identifying SABH, the accuracy of semi-supervised and supervised learning methods is comparable for existing samples, but the unsupervised classification methods tend to misclassify the normal samples as SABH. Among semi-supervised learning methods, the random forest classifier performs the best;In supervised learning methods, decision tree classifiers perform best. Finally, the impact of the number of features on the accuracy of the classifier was analyzed, with 2-3 features being optimal. As an example, the newly obtained experimental data was labelled using semi-supervised learning methods. © 2024 IEEE.

关键词： Bogies (railroad rolling stock)

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Time-synchronous-averaging-spectrum based on super-resolution analysis and application in bearing fault signal identification

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第7期25卷 573-585页

作者： Zengle REN Yuan WANG Huiyue TANG Xin'an CHEN Wei FENG Guangdong Provincial Key Laboratory of Construction Robotics and Intelligent Construction Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055China Shenzhen EBORAIL Technology Co. Ltd.Shenzhen518038China National Supercomputing Center in Shenzhen Shenzhen518055China State Key Lab of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing100044China University of Chinese Academy of Sciences Beijing100190China Shenzhen University of Advanced Technology Shenzhen518107China

Time-synchronous-averaging(TSA)is based on the idea of denoising by averaging,and it extracts the periodic components of a quasiperiodic signal and keeps the extracted waveform *** paper studies the mathematical properties of TSA,where three propositions are given to reveal the nature of *** paper also proposes a TSA-spectrum based on super-resolution analysis and it decomposes a signal without using any base *** contrast to discrete Fourier transform spectrum(DFT-spectrum),which is a spectrum in frequency domain,TSA-spectrum is a period-based spectrum,which can present more details of the cross effects between different periodic components of a quasiperiodic ***,a case study is carried out using bearing fault analysis to illustrate the performance of TSA-spectrum,where the rotation speed fluctuation of the shaft is estimated,which is about 0.12 ms *** extracted fault signals are presented and some insights are *** believe that this paper can provide new motivation for TSA-spectrum to be widely used in applications involving quasiperiodic signal processing(QSP).

关键词： Time-synchronous-averaging(TSA) Spectrum Quasiperiodic signal processing(QSP) Super-resolution analysis Bearingfaultdetection

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Analytical Modelling of a Hybrid Reluctance Motor Based on Magnetic Equivalent Circuit

Analytical Modelling of a Hybrid Reluctance Motor Based on M...

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2023 IEEE International Conference on Industrial technology, ICIT 2023

作者： Su, Xinyi Yang, Xiaofeng Xu, Yunlang Academy for Engineering and Technology Fudan University Shanghai China Fudan University State Key Laboratory of Asic and System Shanghai China

ISBN: (纸本)9798350336504

This study focuses on the analytical modelling of a hybrid reluctance motor (HRM). For the first time, the nonlinear factors of magnetic leakage, fringing flux, and magnetic saturation in the HRM are all considered in the model. Firstly, the magnetic equivalent circuits (MECs) of the magnet and coils are constructed, where the magnetic leakage and fringing flux are handled by the flux tube method. Secondly, the flux ratio criterion (FRC) is introduced to equate the nonlinear relationship between the magnetic field intensity and magnetic flux density to the relative permeability varying with the magnetic flux density. And the flux of each reluctance is calculated by an iterative algorithm. Then, the resultant force of the mover can be further obtained, and the model of the HRM is completed. Finally, the results of the presented model are compared with those of the existing model and finite element analysis (FEA). It can be concluded that the proposed model significantly improves the modelling accuracy, and can well describe the nonlinear characteristics of the HRM. © 2023 IEEE.

关键词： Reluctance motors

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Distinct Westerly Wind Burst Features in Cyclic and Noncyclic El Ni?o Events and Their Association with Western-Central Pacific SST Anomalies

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Advances in Atmospheric Sciences 2025年第6期42卷 1127-1140页

作者： Yu LIU Wenjun ZHANG Zhuolin XUAN Feng JIANG Suqiong HU CIC-FEMD/KLME State Key Laboratory of Climate System Prediction and Risk ManagementNanjing University of Information Science and TechnologyNanjing 210044China Zhejiang Meteorological Observatory Hangzhou 310017China Lamont-Doherty Earth Observatory Columbia UniversityPalisades NY 10964-1707USA

El Ni?o–Southern Oscillation(ENSO) is an oscillation of the ocean–atmosphere system in the tropical Pacific, which is argued to be energized by high-frequency stochastic atmospheric disturbances. Among these disturbances, westerly wind bursts(WWBs) play a crucial role in the development of El Ni?o by generating eastward-propagating downwelling Kelvin waves and suppressing the thermocline in the central-eastern equatorial Pacific. The present work elucidates distinct seasonal evolutions of WWBs during cyclic and noncyclic El Ni?o events, and their association with the local sea surface temperature anomalies(SSTAs). For noncyclic El Ni?o events, WWBs prevail over the western-central equatorial Pacific during spring of the developing year, accompanied by local warming SSTAs. In contrast, active WWBs cannot be observed until the developing summer for cyclic El Ni?o events. Significant differences in high-frequency WWBs and associated local deep convection appear in the developing spring season of noncyclic and cyclic El Ni?o events. These differences are closely linked to local SSTAs in the western-central equatorial Pacific via the stimulation of atmospheric deep convection,preceding the full manifestation of ENSO-associated large-scale SSTAs in the central-eastern tropical Pacific. The observed difference in WWBs for noncyclic and cyclic El Ni?o events and its association with the western-central equatorial Pacific SSTAs is realistically reproduced in a coupled general circulation model. This study enhances our comprehension of El Ni?o development by illustrating the intricate connection between WWBs and El Ni?o evolution from the ENSO cycle perspective.

关键词： westerly wind bursts El Ni?o development cyclic and noncyclic El Ni?o western-central Pacific SST

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Decoupling Design Based on Metasurface Superstrate for Millimeter Wave Antennas

Decoupling Design Based on Metasurface Superstrate for Milli...

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2023 International Applied Computational Electromagnetics Society Symposium, ACES-China 2023

作者： Guo, Jia-Yin Shen, Nan Liu, Feng Zhao, Zhi-Peng Sun, Lei Liu, Tao Xu, Yong Duan, Ya-Juan Tian, Shen Zte Corporation State Key Laboratory of Mobile Network and Mobile Multimedia Technology Department of Rhp System Shaanxi Xi'an China

ISBN: (纸本)9781733509657

A high port isolation millimeter wave antenna array with compact size is proposed in this paper. The center distance between the two E-shaped patches is only 3.2mm, about 0.28 wavelength at center frequency, which will generate a strong mutual coupling. In order to suppress the coupling, a metasurface superstrate consisting of the split-ring resonators is designed, which is placed on the top of the antenna element. The simulation results show that the port isolation of the decoupled antenna array can be improved to over 25dB in the operating frequency range of 24.25-27.5GHz, which demonstrates the effectiveness of the proposed decoupling method. © 2023 Applied Computational Electromagnetics Society (ACES).

关键词： Antenna arrays

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Design and testing of the fuel cell twin-screw air compressor 5

Design and testing of the fuel cell twin-screw air compresso...

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2023 5th International Conference on Energy, Power and Grid, ICEPG 2023

作者： Geng, Maofei Jiang, Huijun Jin, Liqiong Cui, Dong Wang, Le State Key Laboratory of High-end Compressor and System Technology Hefei General Machinery Research Institute Co. Ltd Anhui Hefei230031 China

The oil-free dry air compressor plays a crucial role in the fuel cell system, particularly in commercial buses where twin-screw air compressors have proven effective. A novel rotor profile of the twin-screw dry air compressors has been developed, which simplifies the profile curve and yields excellent performance results with a volume flow of 11.99 m3/min and corrected specific power of 3.54 kW/(m3/min). © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Fuel cells

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TRUSTS: A novel treadmill-based multifunctional testing system for performance evaluation of wheeled planetary exploration rover

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robotics and Autonomous systems 2023年第1期164卷

作者： Yu, Haitao Chen, Jian Pan, Dong Gao, Haibo State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Beijing Institute of Spacecraft System Engineering Beijing100094 China

This paper presents a novel treadmill-based multifunctional testing system (TRUSTS) to execute ground testing for wheeled planetary exploration rover (WPER) in both regular and extreme physical conditions before launching. The TRUSTS with specially-made components featuring compact structure and multifunctional testing items comprises a traction loading subsystem (TLS) and a treadmill-based resistance torque loading subsystem (TRTLS). The former offers the working modes including traction loading, position holding, and range limiting. The latter offers working modes including resistance torque loading and leader–follower tracking. By appropriately allocating the working modes of two subsystems, the TRUSTS is capable of conducting diverse testing items. The customized controllers for the TLS and the TRTLS are proposed to guarantee the operation performance of the TRUSTS in all testing items. Extensive experimental results on a Mars rover prototype in both regular and extreme physical conditions demonstrate that the devised TRUSTS could effectively executing trafficability and maneuverability as well as adaptability tests with reliable scenarios and satisfactory precisions of motion tracking and traction/torque loading, which makes the TRUSTS a favorable choice for comprehensive performance assessment of rover in simulant extraterrestrial environment. © 2023 Elsevier B.V.

关键词： Sporting goods

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Mag-Boost Mechanism for High-Power Ocean Wave Energy Harvesting

SSRN

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SSRN 2024年

作者： Tang, Tianyi Li, Yunfei Huang, Manjuan Mei, Mingqi Wang, Zizhao Zha, Fusheng Sun, Lining Liu, Huicong School of Mechanical and Electrical Engineering Jiangsu Provincial Key Laboratory of Advanced Robotics Soochow University Suzhou215123 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

Ocean wave energy is a highly anticipated renewable energy source. However, due to the ultra-low frequency and random characteristics of ocean waves, efficient and high-power energy harvesting has been a great challenge. By ingeniously leveraging the phenomenon of sudden magnetic-torque variation in orthogonal magnetic fields, this paper proposes an innovative Mag-Boost mechanism, which is capable of converting ultra-low excitation below 1Hz to high-frequency oscillations of power-magnet more than 50Hz without direct contact. The energy conversion efficiency of this mechanism can be as high as 89.3%. By integrating four Mag-boost units into a circular array, a high-power wave energy harvester (WEH) with ultra-low frequency response capabilities has been proposed. At a frequency of 1Hz and an inclination angle of 30°, the WEH demonstrated a high output performance with power of 1.79W and power density of 1.88kW/m³, which is an order of magnitude higher than those of the previous reported ones. During the off-shore test at Yellow Sea, the WEH reached the peak open-circuit voltage of 10V, ensuring completely independent and stable power supply for wireless temperature and humidity sensors. Furthermore, the Mag-Boost mechanism also shows considerable potential for harvesting other forms of low-frequency environmental energy, including wind, vibration, and human kinetic energy. © 2024, The Authors. All rights reserved.

关键词： Water waves

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Mitigating microbiological risks of potential pathogens carrying antibiotic resistance genes and virulence factors in receiving rivers:benefits of wastewater treatment plant upgrade

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Frontiers of Environmental Science & Engineering 2023年第7期17卷 47-55页

作者： Guannan Mao Donglin Wang Yaohui Bai Jiuhui Qu Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Wastewater treatment plants(WWTPs)with additional tertiary ultrafiltration membranes and ozonation treatment can improve water quality in receiving ***,the impacts of WWTP upgrade(WWTP-UP)on pathogens carrying antibiotic resistance genes(ARGs)and virulence factors(VFs)in rivers remain poorly *** this study,ARGs,VFs,and their pathogenic hosts were investigated in three rivers impacted by large-scale WWTP-UP.A five-year sampling campaign covered the periods before and after *** showed that the abundance of total metagenome-assembled genomes(MAGs)containing both ARGs and VFs in receiving rivers did not decrease substantially after WWTP-UP,but the abundance of MAGs belonging to pathogenic genera that contain both ARGs and VFs(abbreviated as PAVs)declined markedly.'Genome-resolved metagenomics further revealed that WWTP-UP not only reduced most types of VFs and ARGs in PAVs,but also effectively eliminated efflux pump and nutritional VFs carried by PAVs in receiving ***-UP narrowed the pathogenic host ranges of ARGs and VFs and mitigated the cooccurrence of ARGs and VFs in receiving *** findings underline the importance of WWTPUP for the alleviation of pathogens containing both ARGs and VFs in receiving rivers。

关键词： Wastewater treatment plant upgrade Antibiotic resistance genes(ARGs) Virulencefactors(VFs) Geneco-occurrence Genome-centric analysis

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Route planning of truck and multi-drone rendezvous with available time window constraints of drones

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Science China(Technological Sciences) 2022年第9期65卷 2190-2204页

作者： LIANG ChengYuan LUO Xin CHEN XueDong HAN Bin School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Guangdong Intelligent Robotics Institute Dongguan 523808China

During the scenarios of cooperative tasks performed by a single truck and multiple drones,the route plan is prone to failure due to the unpredictable scenario *** this situation,it is significant to replan the rendezvous route of the truck and drones as soon as possible,to ensure that all drones in flight can return to the truck before running out of *** paper addresses the problem of rendezvous route planning of truck and *** to the available time window constraints of drones,which limit not only the rendezvous time of the truck and drones but also the available period of each drone,there are obvious local optimum phenomena in the investigated problem,so it is difficult to find a feasible solution.A two-echelon heuristic algorithm is *** the algorithm,the strategy jumping out of the local optimum and the heuristic generating the initial solution are introduced,to improve the probability and speed of obtaining a feasible solution for the rendezvous *** results show that the feasible solution of the truck-drones rendezvous route can be obtained with 88%probability in an average of 77 iterations for the scenario involving up to 25 *** influence of algorithm options on planning results is also analyzed.

关键词： truck and multi-drone rendezvous route planning available time window two-echelon heuristic strategy jumping out of local optimum

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