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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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Dynamic Analysis of Service-oriented Advanced avionics system based on Stochastic Evolutionary Game

Dynamic Analysis of Service-oriented Advanced Avionics Syste...

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2022 Chinese Automation Congress, CAC 2022

作者： Liu, Zhaohui Liu, Qingchun Li, Bingfei Zhang, Shuo China National Aeronautical Radio Electronic Research Institute National Key Laboratory of Science and Technology on Avionics System Integration Shanghai China

ISBN: (纸本)9781665465335

Service-oriented advanced avionics system(SOAAS) is a complex network system with different stakeholders. Stake-holders are irrational behavior and may take aberrant behaviors in advanced avionics system. Different behavior will lead the avionics system to different states. In order to accurately predict the development trend of SOAAS and grasp its dynamic characteristics, stochastic evolutionary game theory is applied to study and analyze SOAAS in this paper. A multi-party game model is constructed to describe the behaviours of participant, and Ito stochastic differential equation is established based on stochastic theory to break through the limitation of replicator dynamics equation. The stability problem of SOAAS is effectively analyzed, and sufficient conditions of system stability are given. Simulation results show the correct and practicable of the established game model and analysis method. © 2022 IEEE.

关键词： Stochastic systems

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An Assumption of R&D Method Driven by Model and Data 1

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14th International Conference on Complex systems Design and Management, CSD and M 2023

作者： Song, Wenming Li, Kui National Key Laboratory of Science and Technology on Avionics Integration Shanghai China China Aeronautical Radio Electronics Research Institute Shanghai200233 China

ISBN: (数字)9789819965113

ISBN: (纸本)9789819965106

The model-based systems engineering is gradually applied to the development of complex systems, it has the advantages of accurate transmission of design output, rapid response to design changes, and undemanding reuse of design achievements. In this paper, MBSE is evaluated from three perspectives, including the theoretical system of model-driven research and development (R&D), the requirements of product R&D as well as the requirements of complex system R&D, and the shortcomings of MBSE are sorted out. On this basis, this paper proposes the R&D process of complex system hybrid-driven by model and data, and analyzes the key technologies to be solved. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Digital devices

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Detection of manganese nodule ore based on underwater hyperspectral imaging technology 6

Detection of manganese nodule ore based on underwater hypers...

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6th Conference on Frontiers in Optical Imaging and technology: Applications of Imaging Technologies

作者： Shen, Mengling Men, Shaojie Liu, Bohan Li, Dewei Liu, Zhaojun School of Information Science and Engineering Shandong University China Key Laboratory of Laser and Infrared System Integration Technology Ministry of Education China Shandong Provincial Key Laboratory of Laser Technology and Application China National Deep Sea Center China

ISBN: (数字)9781510679757

ISBN: (纸本)9781510679740

Manganese nodules, widely distributed across the deep-sea floor, are emerging as a significant potential mineral resource. Addressing the need for improved exploration and classification methods, this study explores the application of underwater hyperspectral imaging technology for the detection and classification of manganese nodule ore and other rock types. The system, operating within a spectral range of 400 - 1000 nm and achieving a spectral resolution of less than 5 nm, captures the spectral characteristics and spatial information of manganese nodule ores. Different classifiers, including Spectral Angle Mapper (SAM), Support Vector Machine (SVM), and Convolutional Neural Networks (2D-CNN and 3D-CNN) to analyze the spectral data. Our results indicate that the four classifiers can effectively achieve ore classification, and CNN-based classifiers significantly outperform traditional SAM and SVM methods. The 2D-CNN model achieved the highest OA at 92.27%, closely followed by the 3D-CNN model at 91.77%. Our findings demonstrate the potential of underwater hyperspectral imaging combined with advanced machine learning techniques in marine mineral detection and environmental monitoring. © 2024 SPIE.

关键词： Support vector machines

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UAV-Assisted Dynamic Avatar Task Migration for Vehicular Metaverse Services: A Multi-Agent Deep Reinforcement Learning Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 430-445页

作者： Jiawen Kang Junlong Chen Minrui Xu Zehui Xiong Yutao Jiao Luchao Han Dusit Niyato Yongju Tong Shengli Xie IEEE School of Automation Guangdong University of TechnologyGuangzhou 510006China 111 Center for Intelligent Batch Manufacturing based on IoT Technology Guangzhou 510006China Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China School of Computer Science and Engineering Nanyang Technological UniversitySingaporeSingapore Pillar of Information Systems Technology and Design Singapore University of Technology and DesignSingaporeSingapore College of Communication Engineering Army Engineering University of PLANanjing 210007China National Natural Science Foundation of China Beijing 100085China Key Laboratory of Intelligent Detection and IoT in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangzhou 510006China

Avatars, as promising digital representations and service assistants of users in Metaverses, can enable drivers and passengers to immerse themselves in 3D virtual services and spaces of UAV-assisted vehicular Metaverses. However, avatar tasks include a multitude of human-to-avatar and avatar-to-avatar interactive applications, e.g., augmented reality navigation,which consumes intensive computing resources. It is inefficient and impractical for vehicles to process avatar tasks locally. Fortunately, migrating avatar tasks to the nearest roadside units(RSU)or unmanned aerial vehicles(UAV) for execution is a promising solution to decrease computation overhead and reduce task processing latency, while the high mobility of vehicles brings challenges for vehicles to independently perform avatar migration decisions depending on current and future vehicle status. To address these challenges, in this paper, we propose a novel avatar task migration system based on multi-agent deep reinforcement learning(MADRL) to execute immersive vehicular avatar tasks dynamically. Specifically, we first formulate the problem of avatar task migration from vehicles to RSUs/UAVs as a partially observable Markov decision process that can be solved by MADRL algorithms. We then design the multi-agent proximal policy optimization(MAPPO) approach as the MADRL algorithm for the avatar task migration problem. To overcome slow convergence resulting from the curse of dimensionality and non-stationary issues caused by shared parameters in MAPPO, we further propose a transformer-based MAPPO approach via sequential decision-making models for the efficient representation of relationships among agents. Finally, to motivate terrestrial or non-terrestrial edge servers(e.g., RSUs or UAVs) to share computation resources and ensure traceability of the sharing records, we apply smart contracts and blockchain technologies to achieve secure sharing management. Numerical results demonstrate that the proposed approach

关键词： Avatar blockchain metaverses multi-agent deep reinforcement learning transformer UAVs

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INFORMATION DISTRIBUTION METHOD FOR MULTI-AIRCRAFT COOPERATION BASED ON COLLABORATIVE FILTERING ALGORITHM 32

INFORMATION DISTRIBUTION METHOD FOR MULTI-AIRCRAFT COOPERATI...

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32nd Congress of the International Council of the Aeronautical sciences, ICAS 2021

作者： Wang, Yunhui Zhan, Zhijuan Xue, Bing Deng, Pingyu National Key Laboratory of Science and Technology on Avionics System Integration Shanghai200233 China

ISBN: (纸本)9783932182914

The information interaction in the formation tasks has higher and higher requirements on the timeliness of the communication system, but the electromagnetic environment in the confrontation environment is extremely unfavorable for the communication channel. Therefore, the high speed, high bandwidth and information interaction environmental interference, security, and cyber defense are the main contradictions in information interaction in systemic joint operations. The core task of the information distribution system is to maximize the compression of information content and reduce the pressure on information distribution to the communication system under the premise of ensuring the information needs of the node. The information distribution system mainly improves the periodic information distribution to distribution on demand, and global broadcast to accurate information push, realizing optimized information distribution. The information distribution algorithm based on collaborative filtering can effectively reduce the acquiring time, improve the accuracy of information for nodes, reduce communication bandwidth, and improve the information interaction efficiency of informationized operations. © 2021 32nd Congress of the International Council of the Aeronautical sciences, ICAS 2021. All rights reserved.

关键词： Aircraft

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Nanoscale phase management of the 2D/3D heterostructure toward efficient perovskite solar cells

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science Bulletin 2024年第18期69卷 2853-2861页

作者： Hao Gu Annan Zhu Junmin Xia Wang Li Jiahao Zheng Tao Yang Shengwen Li Nan Zhang Shiliang Mei Yongqing Cai Shi Chen Chao Liang Guichuan Xing Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoMacao 999078China State Key Laboratory of Organic Electronics and Information Displays&Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing University of Posts&Telecommunications(NUPT)Nanjing 210023China MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter School of PhysicsNational Innovation Platform(Center)for Industry-Education Integration of Energy Storage TechnologyXi’an Jiaotong UniversityXi’an 710049China Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic SystemsHarbin Institute of TechnologyShenzhen 518055China Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China

The stabilization of the formamidinium lead iodide(FAPbI_(3))structure is pivotal for the development of efficient photovoltaic *** two-dimensional(2D)layers to passivate the threedimensional(3D)perovskite is essential for maintaining the a-phase of FAPbI_(3) and enhancing the power conversion efficiency(PCE)of perovskite solar cells(PSCs).However,the role of bulky ligands in the phase management of 2D perovskites,crucial for the stabilization of FAPbI_(3),has not yet been *** this study,we synthesized nanoscale 2D perovskite capping crusts with=1 and 2 Ruddlesden-Popper(RP)perovskite layers,respectively,which form a type-Ⅱ 2D/3D *** heterostructure stabilizes the a-phase of FAPbI_(3),and facilitates ultrafast carrier extraction from the 3D perovskite network to transport contact *** introduced tri-fluorinated ligands to mitigate defects caused by the halide vacancies and uncoordinated Pb^(2+)ions,thereby reducing nonradiative carrier recombination and extending carrier *** films produced were incorporated into PSCs that not only achieved a PCE of 25.39%but also maintained 95%of their initial efficiency after 2000 h of continuous light exposure without *** findings underscore the effectiveness of a phase-pure 2D/3D heterostructure-terminated film in inhibiting phase transitions passivating the iodide anion vacancy defects,facilitating the charge carrier extraction,and boosting the performance of optoelectronic devices.

关键词： Phase-pure 2D perovskite 2D/3D heterostructure Type-II energy alignment Carrier dynamic FAPbI_(3)

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Nonequilibrium carrier and phonon dynamics in the ferrimagnetic semiconductor Mn3Si2Te6

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Physical Review B 2024年第17期109卷 174309-174309页

作者： Y. Yang X. T. Chen Z. L. Li J. B. Pan F. Jing S. S. Zhang X. B. Wang J. L. Luo Key Laboratory of Education Ministry for Laser and Infrared System Integration Technology Beijing National Laboratory for Condensed Matter Physics School of Information Science and Engineering

We investigate the ultrafast carrier and phonon dynamics in the ferrimagnetic semiconductor Mn3Si2Te6 using time-resolved optical pump-probe spectroscopy. Our results reveal that the electron-phonon thermalization process with a subpicosecond timescale is prolonged by the hot-phonon bottleneck effect. We identify the subsequent relaxation processes associated with two nonradiative recombination mechanisms, i.e., phonon-assisted electron-hole recombination and defect-related Shockley-Read-Hall recombination. Temperature-dependent measurements indicate that all three relaxation components show large variation around 175 and 78 K, which is related to the initiation of spin fluctuation and ferrimagnetic order in Mn3Si2Te6. In addition, two pronounced coherent optical phonons are observed, in which the phonon with a frequency of 3.7 THz is attributed to the A1g mode of Te precipitates. Applying the strain pulse propagation model to the coherent acoustic phonons yields a penetration depth of 506 nm and a sound speed of 2.42 km/s in Mn3Si2Te6. Our results develop understanding of the nonequilibrium properties of the ferrimagnetic semiconductor Mn3Si2Te6 and also shed light on its potential applications in optoelectronic and spintronic devices.

关键词： Electron-phonon coupling Ferrimagnets Ultrafast femtosecond pump probe

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Forming Circle Formations of Multi-agent systems Under Actuator Faults 5th

Forming Circle Formations of Multi-agent Systems Under Actu...

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5th Chinese Conference on Swarm Intelligence and Cooperative Control, CCSICC 2021

作者： Liu, Jiajun Ru, Xinfeng Xia, Weiguo Wang, Chen China National Aeronautical Radio Electronic Research Institute and National Key Laboratory of Science and Technology on Avionics System Integration Shanghai China Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education and School of Control Science and Engineering Dalian University of Technology Dalian China National Engineering Research Center of Software Engineering and the State Key Laboratory of Turbulence and Complex Systems Intelligent Biomimetic Design Lab College of Engineering Peking University Beijing China

ISBN: (纸本)9789811939976

A distributed fault-tolerant formation control law is designed in this paper for multi-agent systems under external disturbances and actuator faults including time-varying loss of effectiveness faults. The initial position of each agent is already on a circle and the control purpose is to form a desired formation on this circle. Based on this local information, a distributed adaptive formation control law is designed by employing the congelation of variables method to deal with time-varying actuator faults. Finally, a simulation example is given to verify the effectiveness of the adaptive fault-tolerant control design method. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Multi agent systems

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Hierarchy-based extended CBBA for multi-robot task assignment

Hierarchy-based extended CBBA for multi-robot task assignmen...

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2022 Chinese Automation Congress, CAC 2022

作者： Liu, Jiajun Xia, Weiguo Li, Fuqiang Wang, Peng China National Aeronautical Radio Electronic Research Institute National Key Laboratory of Science and Technology on Avionics System Integration China Dalian University of Technology Key Lab. of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education School of Control Science and Engineering China

ISBN: (纸本)9781665465335

This paper studies the task assignment problem of a multi-robot system with complex constraints including the robot speed limit, the task execution time window constraints, the arrival time, the trip cost, and different priorities of the tasks. A new bidding function is then designed for each robot. Based on the k-means algorithm, a hierarchy-based extended consensus-based bundle algorithm (CBBA) is proposed to find the optimal solution for the task allocation problem. Finally, simulation examples are presented to show the feasibility of the proposed algorithm and comparisons with existing algorithms show that the proposed algorithm can reduce the task assignment time with guaranteed reward values. © 2022 IEEE.

关键词： Multipurpose robots

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