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Staring-imaging satellite pointing estimation based on sequential ISAR images

Chinese Journal of Aeronautics 2024年第8期37卷 261-276页

作者： Canyu WANG Libing JIANG Weijun ZHONG Xiaoyuan REN Zhuang WANG National Key Laboratory of automatic Target Recognition National University of Defense TechnologyChangsha 410073China Xi’an Satellite control Center Xi’an 710600China

Pointing estimation for spacecraft using Inverse Synthetic Aperture Radar(ISAR)images plays a significant role in space situational awareness and ***,feature extraction and cross-range scaling of ISAR images create bottlenecks that limit performances of current estimation ***,the emergence of staring imaging satellites,characterized by complex kinematic behaviors,presents a novel challenge to this *** address these issues,this article proposes a pointing estimation method based on Convolutional Neural Networks(CNNs)and a numerical optimization algorithm.A satellite’s main axis,which is extracted from ISAR images by a proposed Semantic Axis Region Regression Net(SARRN),is chosen for investigation in this article due to its unique ***,considering the kinematic characteristic of the staring satellite,an ISAR imaging model is established to bridge the target pointing and the extracted *** on the imaging model,pointing estimation and cross-range scaling can be described as a maximum likelihood estimation problem,and an iterative optimization algorithm modified by using the strategy of random sampling-consistency check and weighted least squares is proposed to solve this ***,the pointing of targets and the cross-range scaling factors of ISAR images are *** experiments based on actual satellite orbital parameters verify the effectiveness of the proposed *** work can improve the performance of satellite reconnaissance warning,while accurate cross-range scaling can provide a basis for subsequent data processes such as 3D reconstruction and attitude estimation.

关键词： Staring-imaging Agile satellite Inverse Synthetic Aperture Radar(ISAR) Pointing estimation Cross-range scaling

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Uncertainty and disturbance estimator-based model predictive control for wet flue gas desulphurization system

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Chinese Journal of Chemical Engineering 2024年第3期67卷 182-194页

作者： Shan Liu Wenqi Zhong Li Sun Xi Chen Rafal Madonski School of Energy and Environment Key Laboratory of Energy Thermal Conversion and Control of Ministry of EducationSoutheast UniversityNanjing 210096China Faculty of automatic control Electronics and Computer ScienceSilesian University of TechnologyGliwise 44-100Poland

Wet flue gas desulphurization technology is widely used in the industrial process for its capability of efficient pollution *** desulphurization control system,however,is subjected to complex reaction mechanisms and severe disturbances,which make for it difficult to achieve certain practically relevant control goals including emission and economic performances as well as system *** address these challenges,a new robust control scheme based on uncertainty and disturbance estimator(UDE)and model predictive control(MPC)is proposed in this *** UDE is used to estimate and dynamically compensate acting disturbances,whereas MPC is deployed for optimal feedback regulation of the resultant *** viewing the system nonlinearities and unknown dynamics as disturbances,the proposed control framework allows to locally treat the considered nonlinear plant as a linear *** obtained simulation results confirm that the utilization of UDE makes the tracking error negligibly small,even in the presence of unmodeled *** the conducted comparison study,the introduced control scheme outperforms both the standard MPC and PID(proportional-integral-derivative)control strategies in terms of transient performance and ***,the results reveal that a lowpass-filter time constant has a significant effect on the robustness and the convergence range of the tracking error.

关键词： Desulphurization system Disturbance rejection Model predictive control Uncertainty and disturbance estimator Nonlinear system

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Hierarchically Distributed Optimization with a Flexible and Complexity-Reducing Algorithm

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Journal of Systems Science & Complexity 2024年

作者： LIANG Shu ZHANG Lei WEI Yiheng LIU Yemo department of control Science and Engineering Tongji University Shanghai Research Institute for Intelligent Autonomous Systems School of Mathematics Southeast University Beijing Aerospace automatic control Institute

In this paper, the authors consider distributed convex optimization over hierarchical networks. The authors exploit the hierarchical architecture to design specialized distributed algorithms so that the complexity can be reduced compared with that of non-hierarchically distributed *** this end, the authors use local agents to process local functions in the same manner as other distributed algorithms that take advantage of multiple agents' computing resources. Moreover, the authors use pseudocenters to directly integrate lower-level agents' computation results in each iteration step and then share the outcomes through the higher-level network formed by pseudocenters. The authors prove that the complexity of the proposed algorithm exponentially decreases with respect to the total number of pseudocenters. To support the proposed decomposition-composition method for agents and pseudocenters, the authors develop a class of operators. These operators are generalizations of the widely-used subgradient based operator and the proximal operator and can be used in distributed convex optimization. Additionally, these operators are closed with respect to the addition and composition operations; thus, they are suitable to guide hierarchically distributed design and analysis. Furthermore,these operators make the algorithm flexible since agents with different local functions can adopt suitable operators to simplify their calculations. Finally, numerical examples also illustrate the effectiveness of the method.

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Convective drying of wood chips:Accelerating coupled DEM-CFD simulations with parametrized reduced single particle models

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Particuology 2024年第1期84卷 158-167页

作者： Lucas Reineking Jonas Fischer Ali Mjalled Enric Illana Siegmar Wirtz Viktor Scherer Martin Monnigmann automatic control and System Theory Ruhr-Universität-BochumUniversitätstraße 150Bochum44801Germany Energy Plant Technology Ruhr-Universität-BochumUniversitätstraße 150Bochum44801Germany

The simulation of industry-scale reactive bulks is challenging due to the complex interaction between fluid and *** particles in the bulk and their interaction with the fluid flow can be described by combined Discrete Element Method-Computational Fluid Dynamics(DEM-CFD)***,the computational cost of the Finite Volume(FV)methods deployed in these models can become prohibi-tively expensive,especially for high inner-particle *** particle Reduced Models(RMs)can be used to achieve both fast and accurate descriptions of the processes in each *** an example of bulk systems comprising heat and mass transfer,we compared FV and RM simulations for the drying of wood chips in a bulk reactor.A manifold-based nonlinear interpolation was applied to resolve changing boundary conditions for the *** simulations showed that RMs provide accurate values for the thermodynamic state variables of the ***,the time required for the bulk simulation was reduced by 67%with the *** is evident that simulations with high inner-particle resolution can be accelerated by RMs if manifold-based nonlinear interpolation is used to address changing boundary conditions.

关键词： Reduced model Reactive bulk Discrete element method Manifold-based interpolation Drying of porous mediaDEM-CFD

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Real-time UAV path planning based on LSTM network

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Journal of Systems Engineering and Electronics 2024年第2期35卷 374-385页

作者： ZHANG Jiandong GUO Yukun ZHENG Lihui YANG Qiming SHI Guoqing WU Yong School of Electronics and Information Northwestern Polytechnical UniversityXi’an 710129China The Flight automatic control Research Institute of AVIC Xi’an 710065China Military Representative Office of Marine Wuhan Bureau in Luoyang Area Luoyang 471000China

To address the shortcomings of single-step decision making in the existing deep reinforcement learning based unmanned aerial vehicle(UAV)real-time path planning problem,a real-time UAV path planning algorithm based on long shortterm memory(RPP-LSTM)network is proposed,which combines the memory characteristics of recurrent neural network(RNN)and the deep reinforcement learning *** networks are used in this algorithm as Q-value networks for the deep Q network(DQN)algorithm,which makes the decision of the Q-value network has some *** to LSTM network,the Q-value network can use the previous environmental information and action information which effectively avoids the problem of single-step decision considering only the current ***,the algorithm proposes a hierarchical reward and punishment function for the specific problem of UAV real-time path planning,so that the UAV can more reasonably perform path *** verification shows that compared with the traditional feed-forward neural network(FNN)based UAV autonomous path planning algorithm,the RPP-LSTM proposed in this paper can adapt to more complex environments and has significantly improved robustness and accuracy when performing UAV real-time path planning.

关键词： deep Q network path planning neural network unmanned aerial vehicle(UAV) long short-term memory(LSTM)

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LFM Radar Source Passive Localization Algorithm Based on Range Migration

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Journal of Beijing Institute of Technology 2024年第2期33卷 130-140页

作者： Dandan Li Deyi Wang Hao Huan Beijing Key Laboratory of Fractional Signals and Systems School of Information and ElectronicsBeijing Institute of TechnologyBeijing 100081China Beijing Aerospace automatic control Institute Beijing 100854China

Traditional single-satellite passive localization algorithms are influenced by frequency and angle measurement accuracies,resulting in error estimation of emitter position on the order of ***,a single-satellite localization algorithm based on passive synthetic aper-ture(PSA)was introduced,enabling high-precision ***,its estimation of azimuth and range distance is considerably affected by the residual frequency offset(RFO)of uncoopera-tive system ***,it requires data containing a satellite flying over the radia-tion source for RFO *** estimating the RFO,an accurate estimation of azimuth and range distance can be carried out,which is difficult to achieve in practical *** LFM radar source passive localization algorithm based on range migration is proposed to address the dif-ficulty in estimating frequency *** algorithm first provides a rough estimate of the pulse repetition time(PRT).It processes intercepted signals through range compression,range interpola-tion,and polynomial fitting to obtain range migration ***,it uses the changing information of range migration and an accurate PRT to formulate a system of nonlinear equations,obtaining the emitter position and a more accurate PRT through a two-step localization *** offset only induces a fixed offset in range migration,which does not affect the changing *** algorithm can also achieve high-precision localization in squint ***,the effectiveness of this algorithm is verified through simulations.

关键词： passive localization range migration residual frequency offset

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Hybrid Strategy of Partitioned and Monolithic Methods for Solving Strongly Coupled Analysis of Inverse and Direct Piezoelectric and Circuit Coupling

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1371-1386页

作者： Daisuke Ishihara Syunnosuke Nozaki Tomoya Niho Naoto Takayama department of Intelligent and control Systems Kyushu Institute of TechnologyFukuokaJapan

The inverse and direct piezoelectric and circuit coupling are widely observed in advanced electro-mechanical systems such as piezoelectric energy *** strongly coupled analysis methods based on direct numerical modeling for this phenomenon can be classified into partitioned or monolithic *** formulation has its advantages and disadvantages,and the choice depends on the characteristics of each coupled *** study proposes a new option:a coupled analysis strategy that combines the best features of the existing formulations,namely,the hybrid partitioned-monolithic *** analysis of inverse piezoelectricity and the monolithic analysis of direct piezoelectric and circuit interaction are strongly coupled using a partitioned iterative hierarchical *** a typical benchmark problem of a piezoelectric energy harvester,this research compares the results from the proposed method to those from the conventional strongly coupled partitioned iterative method,discussing the accuracy,stability,and computational *** proposed hybrid concept is effective for coupled multi-physics problems,including various coupling conditions.

关键词： Structure-piezoelectric-circuit interaction energy harvesting partitioned method monolithic method hybrid method

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Construction Method of Civil Aircraft Airborne⁃system Supplier Development Process System

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International Journal of Plant Engineering and Management 2024年第2期29卷 65-77页

作者： PU Youhua LI Lin LI Li AVIC Xi′an Flight automatic control Research Institute Xi′an 710076China

Based on the analysis of the development process system status of domestic and foreign civil aircraft airborne system suppliers,this paper proposes the overall construction idea of"a set of civil aircraft process system"based on IPD(Integrated product development)in the *** development stage,process,activity and task are the logical framework elements of the system construction."Based on process decomposition,vertical stratification,horizontal segmentation,combination of special and common,process customized to tools,role and process integration,giving full consideration to the interface between supplier management and process modules"*** the concrete ***,formulate top⁃level system construction standards,implemented by process system management tool platform,so that the process system and development work can be effectively integrated to effectively guide the development work of airborne system suppliers,and meet the quality and airworthiness requirements of civil aircraft *** the development application of a certain type of flight control system,the process system and tool platform were verified and optimized in practice.

关键词： development process system development assurance process integrated product development(IPD) development stage activity

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Trends and Age-Period-Cohort Effect on Incidence of Varicella Under Age 35—China,2005-2021

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China CDC weekly 2024年第18期6卷 390-395,I0005页

作者： Guijie Luan Hongyan Yao Dapeng Yin Jianjun Liu department of Education and Training Chinese center for Disease Control and PreventionBeijingChina Hainan Provincial Center for Disease control and Prevention Haikou CityHainan ProvinceChina Chinese center for Disease control and Prevention BeijingChina

Summary What is already known about this topic?Varicella is an acute respiratory infectious disease primarily affecting ***,recent studies have indicated an increasing susceptibility to varicella among older age *** is added by this report?The findings demonstrate a significant rise in the incidence rate among individuals aged *** under 20 years old were found to have a higher risk compared to females,whereas males had a lower risk compared to females aged 20-35 years.

关键词： acute respiratory Incidence

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Design of MC9 Test Equipment for Inertial Reference System

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International Journal of Plant Engineering and Management 2024年第2期29卷 115-128页

作者： ZHANG Haowen GUAN Hongyang WANG Shuangjia AVIC Xi′an Flight automatic control Research Institute Xi′an 710076China

Inertial reference system is one of the airborne *** to the requirements of SAE ARP4754A Guidelines for Development of Civil Aircraft and Systems,MC9 equipment qualification test is needed to verify that the inertial reference system can perform reservation function under specified service *** is,the inertial reference system shall pass certain environmental tests specified in DO⁃*** tests are faced with the problem that the test equipment should have the function requirements of isolation protection and load ***,a kind of test equipment which can provide isolation protection and simulate load function in the test is designed.

关键词： inertial reference system MC9 isolation protection simulated load

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