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Refined modeling and experimental verification of a torque motor for an electro-hydraulic servo valve

Chinese Journal of Aeronautics 2023年第6期36卷 302-317页

作者： Zhichuang CHEN Shenghong GE Yulei JIANG Wenhao CHENG Yuchuan ZHU National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing Engineering Institute of Aircraft SystemsNanjing 210061China AVIC Nanjing Servo Control System Co. LtdNanjing 210032China

The Permanent Magnet Torque Motor(PMTM)is the key electro-mechanical conversion device in an Electro-Hydraulic Servo Valve(EHSV).In this work,a refined model of a PMTM is developed,considering the non-working air-gaps between the upper or lower yoke and the armature,the fringing effect at the limiting holes,and the nonlinear permeability of soft magnetic *** on the refined model,the influences of various factors on the calculation accuracy of the magnetic flux at the pole surfaces of the armature and the output torque are *** verifying the validity of the refined model,a Finite Element Analysis(FEA)of the PMTM is conducted,and a test platform is *** with existing models,the refined model can better reveal the intrinsic mechanism of the PMTM,and its calculations are more consistent with the FEA *** experimental results of the armature deflection displacement show that the refined model can accurately describe the output characteristics of the PMTM.

关键词： Calculation accuracy Electro-hydraulic servo valve Experimental verification Finite element analysis Refined model Torque motor

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A Dual-Band Rotational Feed Circularly Polarized RFID Reader Antenna Array with Stable Gain

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IEEE Antennas and Wireless Propagation Letters 2025年

作者： Wei, Kun Liu, Jie Xu, Rui Hu, Wei Chen, Chunhong Jiang, Wen Gao, Steven Xidian University National Key Laboratory of Radar Detection and Sensing Xi'an710071 China Science and Technology on Electromechanical Dynamics Control Laboratory Xi'an China School of Electronic and Optical Engineering Nanjing University of Science and Technology Nanjing China Chinese University of Hong Kong Department of Electronic Engineering Hong Kong Hong Kong

In this letter, a dual-band rotational feed circularly polarized (CP) antenna array is proposed. The dual-band antenna element consists of two pairs of symmetric dipoles. The low-frequency CP radiation is achieved by the longer dipole pair, and the high-frequency radiation is mainly superimposed by the shorter dipole pair of the fundamental mode and the longer dipole pair of the higher-order mode. A compact and low-profile antenna array with a 1-to-4 rotational feeding network is introduced. The measured |S11| © 2002-2011 IEEE.

关键词： Circular polarization

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Research on UAV Detection technology of Gm-APD Lidar Based on YOLO Model

Research on UAV Detection Technology of Gm-APD Lidar Based o...

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2021 IEEE International Conference on Unmanned Systems, ICUS 2021

作者： DIng, Yuanxue Qu, Yanchen Zhang, Qing Tong, Jiahui Yang, Xianhui Sun, Jianfeng Harbin Institute of Technology National Key Laboratory of Science and Technology on Tunable Laser Institution of Opto-Electronics Harbin China Beijing Electromechanical Engineering Institute Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing China

ISBN: (纸本)9780738146577

In recent years, unmanned aerial vehicle (UAV) technology has developed rapidly, which plays an important role in both military and civil fields. While it brings convenience to all walks of life, there are also a lot of security problems. Therefore, it is necessary to study anti-UAV technology, but the detection of UAV is an important basis of anti-UAV technology. In this paper, by combining the three-dimensional range profile collected by Gm-APD (Geiger mode Avalanche Photo Diode) lidar with the deep learning method, a UAV detection method based on the improved YOLOv3 (You Only Look Once v3) network is proposed. Firstly, the data of UAV in low altitude real scene is collected by Gm-APD lidar, and range profile information is generated. Then, the YOLOv3 network is improved, and the SPP module can be added to combine the local features of the target with the global features to improve the detection accuracy. It is suitable for the detection of UAVs. Finally, the trajectory of the UAV is drawn based on the distance information. The experimental results show that the improved method can effectively detect UAV targets, and is better than the previous method, YOLOv3-Tiny method and YOLOv4 method. The farthest detection distance is 238m, the detection speed is fast, and the purpose of real-time detection and positioning can be achieved. Therefore, this method can be applied to anti-UAV technology and has important research significance. © 2021 IEEE.

关键词： Optical radar

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Elementary reaction kinetic model of an anode-supported syngas fueled solid oxide fuel cell considering the carbon deposition effect 17

Elementary reaction kinetic model of an anode-supported syng...

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17th International Symposium on Solid Oxide Fuel Cells, SOFC 2021

作者： Zhang, R. Wang, Y. Shi, Y. Wang, Y. Cao, H. National Key Laboratory on Electromechanical Dynamic Control Beijing Institute of Technology Beijing100081 China Department of Energy and Power Engineering Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Tsinghua University Beijing100084 China

ISBN: (纸本)9781607685395

A one-dimensional transient elementary reaction kinetic model of an anode supported solid oxide fuel cell (SOFC) fueled with syngas is developed considering the carbon deposition effect. This model incorporates the coupling effect of heterogeneous elementary chemical and electrochemical reactions, the electrode microstructure and the charge and mass transport processes. The model is validated by both experimental I-V curves and electrochemical impedance spectra. The simulation results agree reasonably well with the experimental data. The numerical results of carbon deposition simulation indicate that the surface carbon coverage can be decreased by increasing the operating temperature and reducing the carbon dioxide, methane or carbon monoxide in the fuel. © 2021 Electrochemical Society Inc.. All rights reserved.

关键词： Carbon monoxide

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Double-Layered Microcracks Coupled Strain Sensors with High Sensitivity and Wide Working Range

SSRN

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SSRN 2024年

作者： Wang, Zihao Liang, Cuiyuan Yang, Yuanhe Sun, Jiaxue Zhang, Xuelin Wang, Yu Jiang, Ying Liu, Yan Qi, Dianpeng MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage National and Local Joint Engineering Laboratory for Synthesis Transformation and Separation of Extreme Environmental Nutrients School of Chemistry and Chemical Engineering Harbin Institute of Technology Harbin150001 China Key Laboratory of Science and Engineering for the Multi-modal Prevention and Control of Major Chronic Diseases Ministry of Industry and Information Technology Zhengzhou Research Institute Harbin Institute of Technology Zhengzhou450000 China School of Astronautics Harbin Institute of Technology Harbin150001 China Department of Electromechanical Engineering Centre for Artificial Intelligence and Robotics University of Macau 999078 China

The flexible strain sensor is a crucial component of the wearable technology, offering considerable potential for monitoring physiological signals. Notably, strain sensors based on nanomaterial thin films have gained much attention from researchers due to their excellent performance and ease of preparation. Nevertheless, challenges remain, such as the rapid expansion of cracks in rigid conductive films under strain, which greatly reduces the working range of the sensors. Conversely, soft conductive films characterized by small cracks are much less sensitive. This study introduces a novel conductive strategy centered on the double-layered microcracks of gold/PPy (Polypyrrole) composite films. The as-prepared strain sensor exhibits ultra-high sensitivity with a gauge factor (GF) of approximately 3.604 × 107, an expansive working range spanning from 0% to 60%, high strain resolution at 0.1% and commendable cycling stability exceeding 1000 cycles. The crack formation and sensing mechanisms were thoroughly investigated, elucidating the key role of the double-layered microcracks in enhancing sensing performance. Ultimately, the practicality of the developed sensor for human health monitoring and human-computer interaction was demonstrated by the accurate detection of human motion. © 2024, The Authors. All rights reserved.

关键词： Thin films

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Discovery of the high-entropy carbide ceramic topological superconductor candidate (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C

arXiv

引用

arXiv 2023年

作者： Zeng, Lingyong Wang, Zequan Song, Jing Lin, Gaoting Guo, Ruixin Luo, Si-Chun Guo, Shu Li, Kuan Yu, Peifei Zhang, Chao Guo, Wei-Ming Ma, Jie Hou, Yusheng Luo, Huixia School of Materials Science and Engineering State Key Laboratory of Optoelectronic Materials and Technologies Key Lab of Polymer Composite & Functional Materials Guangzhou Key Laboratory of Flexible Electronic Materials Wearable Devices Sun Yat-Sen University Guangzhou510275 China Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices Center for Neutron Science and Technology School of Physics Sun Yat-Sen University Guangzhou510275 China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing100190 China Key Laboratory of Artificial Structures and Quantum Control Shenyang National Laboratory for Materials Science School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen518055 China International Quantum Academy Shenzhen518048 China School of Electromechanical Engineering Guangdong University of Technology Guangzhou510006 China Wuhan National High Magnetic Field Center Huazhong University of Science and Technology Wuhan430074 China

High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements. Material design and property tailoring possibilities emerge from this new class of materials. Here, we report the discovery of superconductivity around 2.35 K and topological properties in the (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C high-entropy carbide ceramic (HECC), which has not been observed before in any of the investigated HECC. Density functional theory calculations showed that six type-II Dirac points exist in (Ti0.2Zr0.2Nb0.2Hf0.2Ta0.2)C, which mainly contributed from the t2g orbitals of transition metals and the p orbitals of C. Due to the stability of the structure, we also observed robust superconductivity under pressure in this HEC superconductor. This study expands the physical properties of HECs, which may become a new material platform for superconductivity research, especially for studying the coupling between superconductivity and topological physics. Copyright © 2023, The Authors. All rights reserved.

关键词： Carbides

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Numerical model of direct internal reforming SOFC: A Comparison between Anode-support and Metal-support 16

Numerical model of direct internal reforming SOFC: A Compari...

引用

16th International Symposium on Solid Oxide Fuel Cells, SOFC 2019

作者： Wang, Y. Ren, J. Shi, Y. Li, X. National Key Laboratory on Electromechanical Dynamic Control Beijing Institute of Technology Beijing100081 China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University Beijing100084 China

ISBN: (纸本)9781607688747

Direct internal reforming (DIR) operation provides many benefits for solid oxide fuel cells (SOFCs) by eliminating the need for an extra reformer. Anode-supported SOFCs (AS-SOFCs) are commonly used for DIR operations. However, the strong endothermic reforming reactions at the cell entrance may result in large thermal stresses and lead to premature failure. In this study, a two-dimensional model was developed to analyze the differences between the AS-SOFC and the new generation metal-supported SOFC (MS-SOFC) in DIR operations. The model considered the coupling effects of the chemical/electrochemical reactions, the mass/charge/heat transport processes and the thermal mechanical stress. The distributions of temperature, species composition, current density and thermal stress were determined and compared for both structures. The failure probability of the cell was estimated by stress distributions. The results showed that the MS-SOFC led to a gentler temperature distribution and a smaller failure probability with slight performance increase compared to the AS-SOFC. © The Electrochemical Society.

关键词： Solid oxide fuel cells (SOFC)

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Piezoelectric thermoelastic dissipation research of piezoelectric harvester under different vibration 2

Piezoelectric thermoelastic dissipation research of piezoele...

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2nd International Conference on Electronic Information technology and Computer Engineering, EITCE 2018

作者： Liu, Yuting Deng, Jiahao Ye, Yong Hou, Zhuo Duan, Zuodong Xu, Sha School of Mechatronical Engineering Beijing Institute of Technology Beijing100081 China Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China College of Information Engineering Shenzhen University Shenzhen518060 China National Key Laboratory of Electronic Measurement Technology North University of China Taiyuan030051 China

Piezoelectric materials are widely used to form piezoelectric energy harvesters. Also, the thermoelastic dissipation always influences the energy harvesting efficiency, during the energy harvest process. Therefore, in this paper, we discuss the effect of thermoelastic dissipation on the piezoelectric harvester through numerical calculation, simulation and experiment. The piezoelectric thermoelastic coupling governing equations under different vibration are derived, which are based on the Euler-Bernoulli beam theory, thermal conduction model and piezoelectric field model. Then, the structure frequency shift and thermoelastic damping are studied via numerical calculation and simulation. Meanwhile, we show the influence of the temperature field on the piezoelectric structure under different vibration modes. Furth more, we research the variations of piezoelectric structure thermoelastic dissipation characteristics under different structure geometry sizes. Based on these analyses, the effect of piezoelectric thermoelastic dissipation on the piezoelectric harvester is researched © The Authors, published by EDP sciences, 2018.

关键词： Energy harvesting

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Convergence Properties of the Heterogeneous Deffuant-Weisbuch Model

arXiv

引用

arXiv 2019年

作者： Chen, Ge Su, Wei Mei, Wenjun Bullo, Francesco National Center for Mathematics and Interdisciplinary Sciences Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China School of Automation and Electrical Engineering University of Science and Technology Beijing Beijing100083 China Automatic Control Laboratory ETH Zurich8092 Switzerland Department of Mechanical Engineering The Center of Control Dynamical-Systems and Computation University of California Santa BarbaraCA93106-5070 United States

The Deffuant-Weisbuch (DW) model is a bounded-confidence opinion dynamics model that has attracted much recent interest. Despite its simplicity and appeal, the DW model has proved technically hard to analyze and its most basic convergence properties, easy to observe numerically, are only conjectures. This paper solves the convergence problem for the heterogeneous DW model with the weighting factor not less than 1/2. We establish that, for any positive confidence bounds and initial values, the opinion of each agent will converge to a limit value almost surely, and the convergence rate is exponential in mean square. Moreover, we show that the limiting opinions of any two agents either are the same or have a distance larger than the confidence bounds of the two agents. Finally, we provide some sufficient conditions for the heterogeneous DW model to reach *** Codes 93E03, 93A30, 91D30 Copyright © 2019, The Authors. All rights reserved.

关键词： Economic and social effects

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Piezoelectric thermoelastic dissipation research of piezoelectric harvester under different vibration

Piezoelectric thermoelastic dissipation research of piezoele...

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2018 2nd International Conference on Electronic Information technology and Computer Engineering (EITCE 2018)

作者： Yuting Liu Jiahao Deng Yong Ye Zhuo Hou Zuodong Duan Sha Xu School of Mechatronical Engineering Beijing Institute of Technology Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology College of Information Engineering Shenzhen University National Key Laboratory of Electronic Measurement Technology North University of China

关键词： Piezoelectric thermoelastic dissipation research of piezoelectric harvester under different vibration

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