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1st International Conference on Spatial Atmospheric Marine Environmental Optics, SAME 2023

作者： Xu, He Sun, Difeng Li, Jianbing National University of Defense Technology State Key Laboratory of Complex Electromagnetic Environmental Effects on Electronics and Information System College of Electronic Science and Technology Hunan Changsha410073 China Northwest Institute of Nuclear Technology Shaanxi Xi’an710024 China

ISBN: (纸本)9781510666337

By constructing an external circulating cavity to provide sufficient delay that equals a multiple of pulse repetition time, a method with a fixed experimental configuration is proposed to measure the coherence length of both single-frequency and microwave-modulated optical pulses. This method can accurately determine the number of coherent pulses as well as distinguish the coherence states: complete coherence, partial coherence and complete incoherence. In addition, all desired coherence phenomena are obtained by one-time measurement, avoiding other operations like frequent fiber-cutting or devices-reconnection in previous methods. Simulation results show that the coherence length of the dual-frequency laser is periodically extended by the reciprocal of the frequency difference, and the random jitter of pulse propagation time would result in obvious measurement errors via perturbing coherence status. © 2023 SPIE.

关键词： Random errors

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Measurement-based Path Loss Prediction and Analysis in Water Scenarios

Measurement-based Path Loss Prediction and Analysis in Water...

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2024 IEEE International Conference on Computational Electromagnetics, ICCEM 2024

作者： Li, Hanpeng Chen, Xiaomin Li, Hangang Ma, Jian Ye, Xuchao Song, Lixin Zhang, Taotao Zhong, Weizhi Zhu, Qiuming Nanjing University of Aeronautics and Astronautics College of Electronic and Information Engineering Nanjing211106 China Aviation Key Laboratory of Science and Technology On Aero Electromechanical System Integration Nanjing211106 China State Key Lab. of Complex Electromagnetic Environment Effects On Electronics and Information System Luoyang471003 China

ISBN: (纸本)9798350383317

Unmanned aerial vehicles (UAVs) have enabled the unmanned management of water areas. Path loss (PL) serves as a critical factor that affects the UAV communication quality. In this work, a PL model for UAV channel in water scenarios is proposed, aiming to explore the multidimensional relationship between transceiver distance, carrier frequency, UAV height, and PL by constructing an Artificial Neural Network (ANN). Moreover, channel measurements are conducted in a river area, and the obtained data are analyzed using the proposed ANN model as well as the close-in (CI) model. The analysis results demonstrates that the PL increases initially and then declines as the UAV height increases. The proposed ANN model has higher prediction accuracy than the classic empirical model, and can achieve precise prediction of the PL in water scenarios. © 2024 IEEE.

关键词： Neural networks

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Weak-Model Based Reinforcement Learning Control Strategy of Aircraft Attitude system

Weak-Model Based Reinforcement Learning Control Strategy of ...

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International Conference on Guidance, Navigation and Control, ICGNC 2020

作者： Huang, Dingcui Hu, Jiangping Peng, Zhinan Hao, Mingrui School of Automation Engineering University of Electronic Science and Technology of China Chengdu611731 China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing100074 China

ISBN: (纸本)9789811581540

Intelligent aircraft control is an important strategic development trend. Traditional aircraft control algorithms have a strong dependence on the system models, and it is difficult to cope with the increasingly complex battlefield environment for intelligent aircrafts. In this paper, an online intelligent controller design based on a weak-model reinforcement learning technology is proposed to solve stabilization problem of an aircraft. The control problem is firstly converted to an optimal control problem, then an adaptive dynamic programming (ADP) technology is applied for computing the corresponding nonlinear Hamilton-Jacobi-Bellman equation (HJB) equation. Then, actor-critic neural networks structures are established to learn the optimal controller online where only partial information of the aircraft dynamics is required. The proposed control strategy enables the aircraft to adjust and update its control strategy on-line according to the actual mission targets and environments, such that the requirements of autonomous learning and intelligent operation can be realized. Finally, simulation example is offered to validate the effectiveness of the proposed weak-model based controller design. © 2022, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Reinforcement learning

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Improved A∗Algorithm based on Multi-Layers and Multi-Constraints 23

Improved A∗Algorithm based on Multi-Layers and Multi-Constr...

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4th International Conference on Artificial Intelligence in Electronics Engineering, AIEE 2023

作者： Han, Jian Zhou, Lili Tong, Jiahui Sun, Shiguo Hou, Mingyun Beijing Electro-Mechanical Engineering Institute China and Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing China Beijing Electro-Mechanical Engineering Institute Beijing China

ISBN: (纸本)9781450399517

In this study, an improved A∗algorithm based on multi-layers and multi-constraints is proposed for solving the problem that A∗algorithm must detour when encounters obstacles due to the deficiency of vertical dimension. Detailed obstacle classification and shift method among layers are introduced to make the mathematical environment closer to the real environment and support the calculation of proposed cost function. In the procedure of planning, more interested points are taken into consideration to increase the opportunity of find more reasonable path and achieve lower route cost during approaching the target. Shared forbidden area and shift cost mechanism are set to make sure the trend is right without shift too often. The improved algorithm can provide a better and flexible solution to cross obstacles other than make a detour, so the optimal route find by it has a shorter length than that by the traditional one. © 2023 ACM.

关键词： Cost functions

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Fixed-Time Cooperative Tracking for Delayed Disturbed Multi-Agent systems Under Dynamic Event-Triggered Control

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IEEE/CAA Journal of Automatica Sinica 2022年第5期9卷 930-933页

作者： Jian Liu Yongbao Wu Mengwei Sun Changyin Sun School of Automation Southeast UniversityNanjing 210096 Key Laboratory of Measurement and Control of Complex System of Engineering Ministry of EducationSoutheast UniversityNanjing 210096China Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China IEEE

Dear editor,Recently,researchers have obtained many new results about the multi-agent systems(MASs)[1]-[3].In[1],the fixed-time cooperative control(FTCC)algorithm of linear MASs with matched disturbances was *** nonholonomic chained-form dynamics case was considered in[2].In[3],the output tracking problem with data packet dropout was solved for high-order ***,delay frequently occurs because of the non-ideal data transmission[4],and the corresponding FTCC algorithm of MASs with delay was given in[5].

关键词： editor Dynamic Trigger Event

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Experimental Study on Fragmentation Law of Propellant Bed Under the Mechanics Situation in the Chamber 2nd

Experimental Study on Fragmentation Law of Propellant Bed Un...

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2nd International Conference of Mechanical system Dynamics, ICMSD 2023

作者： Wang, Yan Li, Chao Zhao, Xin Rui, Xiaoting Li, Dayong Lin, Zhicheng Zhang, Puhui Institute of Launch Dynamics Nanjing University of Science and Technology Nanjing China National Key Laboratory of Complex Multibody System Dynamics Nanjing China China North Chemical Research Academy Group Co. LTD Beijing China

ISBN: (纸本)9789819980475

A lot of propellant grains fragmented at the bottom of projectile by the intergranular compression stress is the main reason to cause bore burst. Therefore, the test device for dynamic compression fracture of propellant charge was established to simulate the compression and fractured of propellant bed at the bottom of projectile in the chamber. Based on the Theory of two-phase flow dynamics in interior ballistics, the simulation calculation showed that the intergranular compression stress from the bottom to 30 mm from the bottom of the projectile was greater than that in other places. The application of the dynamic compression fracture device of propellant charge is used to obtain the fragmentation degrees of the propellant beds with different diameters under the same dynamic load. The simulation beds with diameters of 76 and 105 mm showed similar fragmentation degrees of the propellant beds after compression. In addition, by adjusting the initial conditions of the test, the history of compression stress obtained by the test for dynamic compression fracture of propellant charge was closed to the compression stress curve obtained by the test for the mechanics situation of propellant charge in the chamber. The research results will provide a theoretical basis for the test for dynamic compression fracture of the launching charge, and the test method for the detection and evaluation of the launch safety of propellant charge. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Projectiles

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Experimental research on GM-APD LIDAR point cloud classification algorithm based on deep learning

Experimental research on GM-APD LIDAR point cloud classifica...

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2022 Applied Optics and Photonics China: Advanced Laser technology and Applications, AOPC 2022

作者： Jiang, Yanze Sun, Jianfeng Ding, Yuanxue Jiang, Peng Zhang, Hailong Li, Sining Zhou, Shuaijun National Key Laboratory of Science and Technology on Tunable Laser Institute of OptoElectronic Harbin Institute of Technology Heilongjiang Harbin150001 China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing100074 China Beijing Aerospace Automatic Control Institute Beijing100854 China

ISBN: (纸本)9781510662223

Geiger mode Avalanche Photo Diode (Gm-APD) array lidar is a lidar that can perform single-photon detection. It offers a wide range of applications due to its low power consumption, small size, and extended detecting distance. There haven't been many research on this detector's target classification because of its late development and small detector array. The classification technique based on the Gm-APD array lidar point cloud is the focus of this paper's research: Firstly, the Gm-APD array lidar is utilized to perform imaging tests on four targets from various angles in order to create a target classification *** that, several data preprocessing methods were chosen and implemented based on the characteristics of the obtained data, such as filling in missing values, performing range image and intensity image interpolation, using the principle of keyhole imaging to convert the range image to point cloud data, realizing the information fusion of distance image and intensity image, and using multiple point cloud data enhancement methods. Finally, the point cloud classification networks PointNet and PointNet++ are trained on point cloud data with varying levels of preprocessing, the results are compared and analyzed, and the impact of different preprocessing methods on the classification accuracy of the two networks is determined. Inferences were made and experiments were carried out to verify the inferences. The data set preprocessing method with the highest classification accuracy of the two networks is discovered, laying the groundwork for future Gm-APD lidar target classification and detection research. © 2023 SPIE.

关键词： Optical radar

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Research on Simulation Method of Space-Ground Consistency for UAV Cluster Combat

Research on Simulation Method of Space-Ground Consistency fo...

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International Conference on Autonomous Unmanned systems, ICAUS 2021

作者： Qing, Zhang Jing, Li Jiahui, Tong Jian, Han Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing China Beijing Electromechanical Engineering Institute Beijing China

ISBN: (纸本)9789811694912

The Space-ground consistency of the unmanned aerial vehicle (UAV) cluster combat distributed interactive simulation system is the fundamental guarantee to simulate and reproduce the authenticity and correctness of UAV cluster combat mission, combat environment and combat process. This paper analyzes the common inconsistency problems of UAV cluster combat distributed simulation system, gives the technical connotation of the space-ground consistency of UAV cluster combat simulation, deeply analyzes all kinds of factors that affect the consistency of UAV cluster combat simulation space and ground, and puts forward the control methods of time-space consistency of UAV cluster combat simulation system, the control strategies and suggestions of model consistency and service consistency. It provides a theoretical basis and technical support for the construction of distributed interactive simulation system for UAV cluster combat. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Unmanned aerial vehicles (UAV)

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UAV Training Control and Evaluation Method Based on Dynamic Task Construction 17th

UAV Training Control and Evaluation Method Based on Dynamic ...

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17th Chinese Intelligent systems Conference, CISC 2021

作者： Tong, Jiahui Zhang, Qing Ran, Jian Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing China Beijing Electromechanical Engineering Institute Beijing China

ISBN: (纸本)9789811663277

In view of the problems such as high cost, low training efficiency and lack of versatility, a design scheme of UAV simulation training system based on dynamic mission construction is proposed, and the reproducing dynamic mission environment simulation technology and UAV training control and result evaluation and method are described in detail. The evaluation system of UAV simulation training results based on multi-factor influence data is constructed, which can effectively guide the simulation training of multi-type UAV and improve the overall training effect of UAV operators by synthesizing historical training data and real-time training data. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Unmanned aerial vehicles (UAV)

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Multiscale mechanics of noncovalent interface in graphene oxide layered nanocomposites

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Theoretical & Applied Mechanics Letters 2022年第1期12卷 3-9页

作者： ZeZhou He YinBo Zhu HengAn Wu CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsCAS Center for Excellence in Complex System MechanicsUniversity of Science and Technology of ChinaHefei 230027China

Noncovalent interfaces play a vital role in inelastic deformation and toughening mechanisms in layered nanocomposites due to their dynamical recoverability. When interfacial engineering is applied to design layered nanocomposites, shear-lag analysis is usually implemented to evaluate the capability of interfacial loading transfer. Here, we introduce a multiscale shear-lag model that correlates macroscale mechanical properties with the molecular mechanisms to quantify the effects of interfacial configuration in graphene oxide(GO) layered nanocomposites. By investigating the mechanical responses of commensurate and incommensurate interfaces, we identify that the commensurate interface exhibits a pronounced size effect due to the nucleation and propagation of interfacial defects, whereas the incommensurate interface displays uniform deformation. Our predictions are further validated through large-scale molecular dynamics simulations for GO layered nanocomposites. This work demonstrates how size effects and interfacial configurations can be exploited to fabricate layered nanocomposites with superior mechanical properties despite relying on weak noncovalent interfaces.

关键词： Multiscale mechanics Noncovalent interface Commensurate and incommensurate Shear-lag model Layered nanocomposites

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