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IEEE Asia Power and Energy Engineering Conference (APEEC)

作者： Zhengqing Han Jin Xu Wanzhi Rui Lu Wang Guangbo Li National Key Laboratory of Science and Technology on Vessel Integrated Power System Department of the Naval Equipment Naval University of Engineering Wuhan China

ISBN: (数字)9781728167824

ISBN: (纸本)9781728167831

This paper introduces a linear induction motor with segmented power supply, which transforms the electric energy into the kinetic energy of the load movement in electromagnetic launch system. Based on the characteristics of electromagnetic emission mode, a special electromagnetic force analysis method of the motor is proposed. Firstly, considering secondary edge leakage, based on the principle of port equivalence, the equivalent circuit model is modified, and the calculation method of normal electromagnetic force of linear induction motor which is suitable for aperiodic transient operation in electromagnetic emission situation is analyzed. The accuracy of the method is verified by the finite element software. Secondly, combined with the kinematic model of Newton's second law, the relationship between the magnitude of electromagnetic force and the time of the stator in each section of the motor in the launching process is analyzed in detail, which lays the foundation for the dynamic response analysis and structural optimization design of the subsequent launching device.

关键词： electromagnetic emission linear induction motor with segmented power supply electromagnetic force kinematic model electromagnetic forces Electromagnetic projectiles Linear induction motors kinematics Electric Power Source induction motors computational methods Optimal design

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An FPGA-based HF/VHF/UHF integrated self-interference cancellation system

An FPGA-based HF/VHF/UHF integrated self-interference cancel...

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2019 Joint International Symposium on Electromagnetic Compatibility, Sapporo and Asia-Pacific International Symposium on Electromagnetic Compatibility, EMC Sapporo/APEMC 2019

作者： Xing, Jinling Liu, Yongcai Ge, Songhu Li, Yi Meng, Jin National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan Hubei Province430033 China

ISBN: (纸本)9784885523229

The paper describes the design and performance of an FPGA-based interference cancellation system operating in the 2MHz-500MHz frequency band. The system adopts the RF direct bandpass sampling structure without down-converter introduced. The paper lays stress on the analysis and demonstration of feasibility and design consideration of bandpass sampling technique in the cancellation system, and presents the high speed FPGA realization of the low pass filter - a key module of the adaptive correlation algorithm. Experimental results show that average 64.2dB and 61.8dB suppression are achieved for the ideal sine-wave signal interference and amplitude-modulated signal interference, respectively, presenting an excellent cancellation performance of the proposed system. © 2019 The Institute of Electronics, Information and Communication Engineer.

关键词： Field programmable gate arrays (FPGA)

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Mechanical Analysis and Performance Optimization for the Lunar Rover’s Vane-Telescopic Walking Wheel

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Engineering 2020年第8期6卷 936-943页

作者： Lu Yang Bowen Cai Ronghui Zhang Kening Li Zixian Zhang Jiehao Lei Baichao Chen Rongben Wang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China Guangdong Key Laboratory of Intelligent Transportation System School of Intelligent Systems EngineeringSun Yat-sen UniversityGuangzhou 510275China College of Transportation Jilin UniversityChangchun 130025China Department of Mechanical Science and Engineering Tokyo Institute of TechnologyTokyo 152-8550Japan Armour College of Engineering Illinois Institute of TechnologyChicagoIL 60616USA China Academy of Space Technology Beijing 100029China

It is well-known that optimizing the wheel system of lunar rovers is ***,this is a difficult task due to the complex terrain of the moon and limited resources onboard lunar *** this study,an experimental prototype was set up to analyze the existing mechanical design of a lunar rover and improve its ***,a new vane-telescopic walking wheel was proposed for the lunar rover with a positive and negative quadrangle suspension,considering the complex terrain of the ***,the performance was optimized under the limitations of preserving the slope passage and minimizing power *** was achieved via analysis of the wheel force during ***,the effectiveness of the proposed method was demonstrated by several simulation *** newly designed wheel can protrude on demand and reduce energy consumption;it can be used as a reference for lunar rover development engineering in China.

关键词： Intelligent vehicle Vane-telescopic walking wheel Performance optimization Vane spring Lunar rover

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An iterative method for the solution of equilibrium position in the shaft-hole assembly based on spring contact model

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Procedia CIRP 2021年 97卷 230-234页

作者： Yuanyang Zhang Junkang Guo Xianming Gao Jun Hong School of Mechanical Engineering Xi'an Jiaotong University Xi'an Shaanxi 710049 P R China Key Laboratory for Modern Design & Rotor-Bearing System Ministry of Education Xi'an Jiaotong University Xi'an Shaanxi 710049 P R China College of Mechanical and Electrical Engineering Shaanxi University of Science and Technology Xi'an 710021 China

The traditional finite element method has the advantages of strong versatility and high calculation accuracy. Thus it is widely applied in various numerical simulation problems. Although the traditional finite element method for solving the shaft-hole assembly problem can obtain better solution accuracy, the process of modeling and calculation take a long time and thus cannot meet the engineering application requirements when the equilibrium position after the assembly needs to be obtained quickly to guide the subsequent process. In this paper, an iterative method based on the spring contact model is proposed. Firstly, the actual form error of the shaft and hole is characterized by the Fourier series expansion method; Then, in the contact surface, we established a discrete spring contact model and obtained the equivalent stiffness of the coupling spring through the discrete solid model. The balance iterative calculation based on the form errors and contact deformation force can finally determine the equilibrium position after the assembly. Compared with the calculation results of the finite element model, the equilibrium position of the shaft-hole assembly can be quickly solved under the condition of sacrificing certain precision. From this aspect it can be estimated that this method has a good potential for engineering application.

关键词： Assembly design Form error Spring contact model Finite element method

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Learning to Infer Weather States Using Partial Observations

Journal of Geophysical Research: Machine Learning and Comput...

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Journal of Geophysical Research: Machine Learning and Computation 2025年第1期2卷

作者： Jie Chao Baoxiang Pan Quanliang Chen Shangshang Yang Jingnan Wang Congyi Nai Yue Zheng Xichen Li Huiling Yuan Xi Chen Bo Lu Ziniu Xiao National Key Laboratory of Earth System Numerical Modeling and Application Institute of Atmospheric Physics Chinese Academy of Science Beijing China School of Atmospheric Sciences Chengdu University of Information Technology Chengdu China Key Laboratory of Mesoscale Severe Weather Ministry of Education and School of Atmospheric Sciences Nanjing University Nanjing China College of Computer National University of Defense Technology Hunan China Clustertech LTD Hong Kong China National Climate Center China Meteorological Administration Beijing China

Accurate state estimation of the high-dimensional, chaotic Earth's atmosphere marks a Sisyphean task, yet is indispensable for initiating weather forecasts and gauging climate variability. While much effort is devoted to assimilating observations and forecasts to infer weather states, the inherent low-dimensional statistical structure in atmospheric circulation, shaped by geophysical laws and geographic boundaries, is underutilized as an informative prior for state inference, or as reference for assessing representative of existing observations and planning new ones. We realize these potential by learning climatological distribution from climate reanalysis/simulation, using a deep generative model. For a case study of estimating 2 m temperature spatial patterns, the learned distribution faithfully reproduces climatology statistics. A combination of the learned climatological prior with few station observations yields strong posterior of spatial pattern estimates, which are spatially coherent, faithful and adaptive to observational constraints, and uncertainty-aware. This allows us to evaluate each observation's value in reducing pattern estimation uncertainty, and guide optimal observation network design by pinpointing the most informative sites. Our study showcases how generative models can extract and utilize information produced in the chaotic evolution of climate system. Deep generative model enables accurate spatial interpolation of weather variables from sparse observations The generative model produces spatially coherent and uncertainty-aware estimates, effectively constrained by observational data The approach provides a framework to quantify observation impact on uncertainty reduction, enabling optimization of observation networks Accurate estimation of weather conditions across a large area is crucial but challenging due to the complex and chaotic nature of the atmosphere. Traditional methods rely on combining observations with forecasts, which can be comp

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Multi-Scale Fusion Algorithm for AUVs Integrated Navigation systems

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Journal of Beijing Institute of technology 2019年第4期28卷 725-730页

作者： Yushan Sun Fanyu Wu Yuqi Wang Guocheng Zhang Bin Kong Science and Technology on Underwater Vehicle Laboratory Harbin Engineering UniversityHarbin 150001China Key Laboratory of System Control and Information Processing Shanghai Jiao Tong UniversityShanghai 200030China Wuhan Second Ship Design and Research Institute Wuhan 430205China

To deal with the low location accuracy issue of existing underwater navigation technologies in autonomous underwater vehicles(AUVs),a distributed fusion algorithm which combines the model's analysis method with a multi-scale transformation method is proposed for integrated navigation system based on ***,integrated navigation system theory and system error sources are introduced in ***,a navigation system's observation equation on the original scale is decomposed into different scales by the discrete wavelet transform method,and noise reduction is performed by setting the wavelet de-noising *** last,the dynamic equation and observation equations are fused on different scales by the wavelet transformation and Kalman *** results show that the proposed algorithm has smaller navigation error and higher navigation accuracy.

关键词： autonomous underwater vehicles(AUVs) integrated navigation system wavelet transform multi-scale transform Kalman filter

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Aerodynamic interactions of staggered counter-rotating rotor system

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Chinese Journal of Aeronautics 2025年

作者： He ZHU Yuhao DU Hong NIE Shaoxiong WEI Xiaohui WEI National Key Laboratory of Helicopter Aeromechanics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

With the widespread application of Staggered Counter-rotating Rotor (SCR) systems in eVTOL and UAV configurations, a comprehensive understanding of SCR performance under Out-of-Ground Effect (OGE) and In-Ground Effect (IGE) conditions is crucial for aircraft design and landing safety. This study experimentally measured the changes in thrust and torque of the upper and lower rotors in an SCR system under varying axial and radial distances. It focuses on the interaction mechanisms between the upper and lower rotors and conducts specific IGE state experiments for certain SCR configurations. The findings reveal that changes in the lower rotor predominantly influence the overall performance of the SCR system, regardless of OGE or IGE conditions. Under OGE conditions, radial distance has a more significant impact than axial distance. Conversely, under IGE conditions, the axial distance plays a critical role in improving SCR system performance. These results provide a broad parameter range to assess SCR system performance variations, offering guidance for the design of new concept rotorcraft configurations and the development of aerodynamic prediction models under IGE conditions.

关键词： eVTOL Staggered counter-rotating rotors Aerodynamic interaction Ground effect Flow visualization Rotorcraft design

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design of deep-water omnidirectional spirit level

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Journal of Measurement science and Instrumentation 2021年第4期12卷 472-478页

作者： ZHAO Lianyu LI Shuo ZHAO Xiaolei LI Maolin CHEN Jinyu WANG Chenglin Tianjin Key Laboratory of Advanced Mechatronic System Design and Intelligent Control National Demonstration Center of Experimental Mechanical and Electrical Engineering EducationSchool of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China Offshore Oil Engineering Co. Ltd.Tianjin 300461China

Attitude adjustment is a key link in the installation process of underwater facilities in deep *** solve this problem,an omnidirectional spirit level for deep water was *** sealing principle of the spirit level and the principle of deep-water pressure resistance are analyzed,and the threaded connection strength is *** mechanical simulation verifies that the spirit level can withstand the pressure of 2000 m water depth,and the water pressure test is carried out for 30 min in a 20 MPa hyperbaric *** the experiment is completed,the appearance of the spirit level is intact and there is no *** experiment results show that the deep-water omnidirectional spirit level can be used in the deep sea within 2000 m.

关键词： deep water omnidirectional spirit level attitude adjustment pressure test underwater pressure

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Research on Asymmetrical Dual-rotor system Based on the Energy Orbit

Research on Asymmetrical Dual-rotor System Based on the Ener...

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IEEE International Conference on Mechatronics and Automation

作者： Zhu Han Jun Liu Yu Zhang Tianjin Key Laboratory for Advanced Mechanical System Design and Intelligent Control Tianjin University of Technology Tianjin China National Demonstration Centre for Experimental Mechanical and Electrical Engineering Education Tianjin University of technology

ISBN: (数字)9781728164168

ISBN: (纸本)9781728164175

Studying the vibration of asymmetrical dual-rotor is very important for aero engines. In this paper, based on the vibration characteristics of an aero-engine, a different novel coupled dynamic model is proposed based on the spring recovery characteristics of rotor. The model dynamic equations of asymmetrical dual-rotor are obtained by the Lagrange equation, and vibration resonance curves of high pressure and low pressure rotors are numerically simulated and theoretically analyzed by using the Runge-Kutta algorithm. The research show that the system occurs combined vibration, harmonic vibration and superharmonic vibration. In addition, the vibration occurring mechanism was investigated and verified in detail through numerical simulation. For the first time, the concept of energy orbit was introduced into the dual-rotor model system. The energy orbit represents the vibration characteristics and energy exchange process of the model system. Energy orbit is a new energy orbit method for analyzing vibration characteristics of rotor system. The new researches of this paper will show a different research direction for complex dual-rotor systems.

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Static interface profiles for contact lines on an elastic membrane with the Willmore energy

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Physical Review E 2020年第6期102卷 062803-062803页

作者： Zhen Zhang Jin Yao Weiqing Ren Department of Mathematics Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology (SUSTech) Shenzhen 518055 People's Republic of China Department of Mathematics National University of Singapore Singapore 119076

We consider a fluid interface in contact with an elastic membrane and study the static profiles of the interface and the membrane. Equilibrium conditions are derived by minimizing the total energy of the system with volume constraints. The total energy consists of surface energies and the Willmore energy; the latter penalizes the bending of the membrane. It is found that, while the membrane is locally flat at the contact line with the contact angle satisfying the Young-Dupré equation, the gradient of the mean curvature of the membrane exhibits a jump across the contact line. This jump balances the surface tension of the fluid interface in the normal direction of the membrane. Asymptotic solutions are obtained for two-dimensional systems in the limits as the reduced bending modulus ν tends to +∞ and 0, respectively. In the stiff limit as ν→+∞, the leading-order solution is given by that of a droplet sitting on a rigid substrate with the contact angle satisfying the Young-Dupré equation; in contrast, in the soft limit as ν→0, a transition layer appears near the contact line and the interfaces have constant curvatures in the outer region with apparent contact angles obeying Neumann's law. These solutions are validated by numerical experiments.

关键词： Contact line dynamics Interfacial flows

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