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Modified robust optimal adaptive control for flight environment simulation system with heat transfer uncertainty

Chinese Journal of Aeronautics 2021年第2期34卷 420-431页

作者： Meiyin ZHU Xi WANG Xitong PEI Song ZHANG Zhihong DAN Nannan GU Shubo YANG Keqiang MIAO Huairong CHEN Jiashuai LIU School of Energy and Power Engineering Beihang UniversityBeijing 100083China Collaborative Innovation Center for Advanced Aero Engine Bejing 100083China Science and Technology on Altitude Simulation Laboratory AECC(Aero Engine Corporation of China)Sichuan Gas Turbine EstablishmentMianyang 621000China

To solve the rapid transient control problem of Flight Environment simulation system(FESS) of Altitude Ground Test Facilities(AGTF) with large heat transfer uncertainty and disturbance, a new adaptive control structure of modified robust optimal adaptive control is *** mathematic modeling of FESS is given and the influence of heat transfer is analyzed through energy view. To consider the influence of heat transfer in controller design, we introduce a matched uncertainty that represents heat transfer influence in the linearized system of FESS. Based on this linear system, we deduce the design of modified robust optimal adaptive control law in a general way. Meanwhile, the robust stability of the modified robust optimal adaptive control law is proved through using Lyapunov stability theory. Then, a typical aero-engine test condition with Mach Dash and Zoom-Climb is used to verify the effectiveness of the devised adaptive controller. The simulation results show that the designed controller has servo tracking and disturbance rejection performance under heat transfer uncertainty and disturbance;the relative steady-state and dynamic errors of pressure and temperature are both smaller than 1% and 0.2% respectively. Furthermore,the influence of the modification parameter c is analyzed through simulation. Finally, comparing with the standard ideal model reference adaptive controller, the modified robust optimal adaptive controller obviously provides better control performance than the ideal model reference adaptive controller does.

关键词： Altitude ground test facilities Flight environment simulation system Heat transfer Model reference adaptive control Optimal control modification Uncertainty

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Research on the adjacency effect for off-nadir optical remote sensing

Research on the adjacency effect for off-nadir optical remot...

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2019 IEEE International Conference on Signal, Information and Data Processing, ICSIDP 2019

作者： Ma, Xiaoshan Yang, Zhen Peng, Xiaodong Key Laboratory of Electronics and Information Technology for Space System National Space Science Center Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781728123455

With the application of the multi-angle remote sensing which obtain earth's surface data through several scan angles, the analysis of the adjacency effect in off-nadir optical remote sensing is significant. Monte Carlo method is used to simulate the atmospheric point spread function (PSF) that are appropriate for the off-nadir optical remote sensing. By the convolution of the atmospheric PSF and the surface-leaving radiance, the radiance caused by the adjacency effect could be calculated. The influence factor analysis shows that, in addition to the surface albedo and the meteorological range, the viewing direction will affect the adjacency effect dramatically. With the deviation of the viewing zenith angle from the nadir, adjacency effect becomes weak. Unlike the nadir remote sensing, the adjacency effect in off-nadir remote sensing is azimuthally dependent and the contribution of the background in the viewing direction is greater than others. Based on a three-dimensional scene and a whole chain optical imaging simulation software, the images before the optical system of the sensor with and without the adjacency effect are simulated. The calculation of the SNR, contrast and spatial resolution of the images reveals that the adjacency effect seriously degrades the image quality. These results could provide the basis for modeling the multi-angle optical remote sensing imaging system and exploring the correction algorithm of the adjacency effect. © 2019 IEEE.

关键词： Optical transfer function

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Twin Delayed Multi-Agent Deep Deterministic Policy Gradient

Twin Delayed Multi-Agent Deep Deterministic Policy Gradient

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Symposium of Image, Signal Processing, and Artificial Vision (STSIVA)

作者： Mengying Zhan Jinchao Chen Chenglie Du Yuxin Duan Northwestern Polytechnical University Xi’an China Beijing Simulation Center Science and Technology on Special System Simulation Laboratory Beijing China

ISBN: (纸本)9781665426565

Recently, reinforcement learning has made remarkable achievements in the fields of natural science, engineering, medicine and operational research. Reinforcement learning addresses sequence problems and considers long-term returns. This long-term view of reinforcement learning is critical to find the optimal solution of many problems. The existing multi- agent reinforcement learning algorithms have the problem of overestimation in estimating the Q value. Unfortunately, there have not been many studies on overestimation of agent reinforcement learning, which will affect the learning efficiency of reinforcement learning. Based on the traditional multi-agent reinforcement learning algorithm, this paper improves the actor network and critic network, optimizes the overestimation of Q value and adopts the update delayed method to make the actor training more stable. In order to test the effectiveness of the algorithm structure, the modified method is compared with the traditional MADDPG, DDPG and DQN methods in the simulation environment.

关键词： Training Conferences Reinforcement learning Delays Informatics Convergence

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Near-field error correction on RFSS for applications

Near-field error correction on RFSS for applications

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International Symposium on Antennas, Propagation and EM Theory (ISAPE)

作者： Jing Ma Dong Chen Jindong Fei Science and Technology on Space Simulation Laboratory Beijing China Institute of Telecommunication Satellites Beijing China Science and Technology on Space Simulation Laboratory Beijing China Beijing China

According to the applications for current RFSS(Radio Frequency simulation system) developing, this paper proposes a near-field error correction method using mono-pulse amplitude comparison. This method produces two tables which are used to correct near-field error by adjusting the amplitudes on triad of antenna from the gradation direction to make the error of DOA(Direction-Of-Arrival) approaching zero. Meanwhile, this method focuses on the model of mono-pulse amplitude-comparison for seeker setting with a circular slot array of wave guide. Based on the character of symmetry for the slot array, the process of forming the SUM signal and MINUS signal is simplified. The precision of the tables for near-field error correction by our method satisfies the demands of RFSS with the deflection of 3×10 -3 degree for azimuth and 2×10 -3 degree for elevation. The simplified method also meets the demand of RFSS and reduces the running time by 55%.

关键词： Arrays Azimuth Mathematical model Equations Slot antennas Antenna arrays Error correction

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Performance analysis of moving ship target signal integration and detection in geosynchronous synthetic aperture radar

Performance analysis of moving ship target signal integratio...

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IET International Radar Conference 2018, IRC 2018

作者： Zhang, Ying Dong, Xichao Xiong, Wei Hu, Cheng Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing101416 China Radar Research Lab School of Information and Electronics Beijing Institute of Technology Beijing100081 China Ministry of Education Beijing100081 China

Geosynchronous synthetic aperture radar (GEO SAR) has the characteristics of wide coverage and short revisit time, which makes GEO SAR moving target indication more valuable than other platforms. This article analyses the influence of moving target on 'Stop-and-Go' error in GEO SAR, and then the accurate slant range model of moving target is constructed. The signal-to-noise ratio of the raw data echoes for moving ship target is very low because of the high satellite orbit altitude, so it cannot be detected by constant false alarm detection. Based on the accurate slant range model of moving target in GEO SAR, three kinds of integration methods are reconstructed, including moving target detection, Radon transform and generalised Radon Fourier transform (GRFT). The performance of these methods is compared through numerical simulation. GRFT can provide the best detection performance in a reasonable integration time. © 2019 Institution of Engineering and technology. All rights reserved.

关键词： Numerical methods

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A Multi-Objective Optimization Model for simulation-based Acquisition

A Multi-Objective Optimization Model for Simulation-based Ac...

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Symposium of Image, Signal Processing, and Artificial Vision (STSIVA)

作者： Xue Zhang Junjie Xue Junhua Zhou Guoqiang Shi Yan Yu School of Computer Science and Engineering Nanjing University of Science and Technology Nanjing China Beijing Complex Product Advanced Manufacturing Engineering Research Center Beijing Simulation Center Beijing China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System Engineering Beijing China Science and Technology on Space System Simulation Laboratory Beijing Simulation Center Beijing China

ISBN: (数字)9781728170862

ISBN: (纸本)9781728170879

Large-scale equipment presents the characteristics of technology-intensive, knowledge-intensive and complex, which brings high investment and high risk to equipment acquisition. This paper analyzes the various components of equipment acquisition to fully apply modeling and simulation technology to each stage of it. On the basis of multi-objective optimization theory, the objective function of the lowest risk and lowest cost of simulation-based acquisition (SBA) is proposed. Then establishing a multi-objective optimization model for simulation-based acquisition according to the corresponding constraints. The nondominated sorting genetic algorithm II (NSGA II) and multi-objective particle swarm optimization (MOPSO) algorithms are used to optimize the model, and the majority voting method is used for integration. The comparison of simulation examples proves that the multi-objective optimization model oriented to SBA designed in this paper can effectively realize the optimization of each objective of SBA under cost constraints. And the feasibility and efficiency of optimization solution are guaranteed.

关键词： Analytical models Linear programming Reliability Particle swarm optimization Optimization Sorting Investment

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Research on behavioral decision method of simulation entity based on cognitive model

Research on behavioral decision method of simulation entity ...

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2013 International Conference on Applied Mechanics, Mechatronics and Intelligent system, AMMIS 2013

作者： Yang, Haitao Li, Peng Wei Zhao, Hong Li Science and Technology on Complex Electronic System Simulation Laboratory Academy of Equipment Beijing 101416 China Company of Postgraduate Management Academy of Equipment Beijing 101416 China Academy of Equipment Beijing 101416 China

ISBN: (纸本)9783037857625

This paper studies how to use the cognitive model to model the behavioral decision-making for the tactical level simulation. The decision making process includes initial behavior planning and behavior modification. This method has the advantages of accuracy and real-time, this makes the behaviors of the simulation entity more realistic and improves the credibility of simulation. © (2013) Trans Tech Publications, Switzerland.

关键词： Decision making

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Surface-enhanced Raman scattering for mixing state characterization of individual fine particles during a haze episode in beijing,China

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Journal of Environmental sciences 2021年第6期33卷 216-224页

作者： Hui Chen Fengkui Duan Jingjing Du Ranhao Yin Lidan Zhu Jinlu Dong Kebin He Zhenli Sun Suhua Wang MOE Key Laboratory of Resources and Environmental System Optimization College of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Guangdong Provincial Key Laboratory of Petrochemcial Pollution Processes and Control School of Environmental Science and EngineeringGuangdong University of Petrochemical TechnologyMaoming 525000China

The nondestructive characterization of the mixing state of individual fine particles using the traditional single particle analysis technique remains a *** this study,fine particles were collected during haze events under different pollution levels from September 5 to 112017 in beijing,China.A nondestructive surface-enhanced Raman scattering(SERS)technique was employed to investigate the morphology,chemical composition,and mixing state of the multiple components in the individual fine *** image and SERS spectral analysis results show that soot existing in the form of opaque material was predominant during clear periods(PM_(2.5)≤75μg/m^(3)).During polluted periods(PM_(2.5)>75μg/m^(3)),opaque particles mixed with transparent particles(nitrates and sulfates)were generally *** classical least squares analysis further identified the relative abundances of the three major components of the single particles:soot(69.18%),nitrates(28.71%),and sulfates(2.11%).A negative correlation was observed between the abundance of soot and the mass concentration of PM_(2.5).Furthermore,mapping analysis revealed that on hazy days,PM_(2.5)existed as a core-shell structure with soot surrounded by nitrates and *** mixing state analysis method for individual PM_(2.5)particles provides information regarding chemical composition and haze formation mechanisms,and has the potential to facilitate the formulation of haze prevention and control policies.

关键词： PM_(2.5) Surface-enhanced Raman scattering Individual fine particle Nitrate Sulfate Soot

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The physics-based deterministic scenarios for earthquake hazards and losses of the Zhujiangkou fault in southern China

npj Natural Hazards

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npj Natural Hazards 2025年第1期2卷 1-13页

作者： Yilong Li Ming Wang Kai Liu Houyun Yu Zhenguo Zhang Wei Zhang Xiaofei Chen Xiuwei Ye Joint International Research Laboratory of Catastrophe Simulation and Systemic Risk Governance Beijing Normal University Zhuhai China School of National Safety and Emergency Management Beijing Normal University Zhuhai China Department of Earth and Space Sciences Southern University of Science and Technology Shenzhen China School of National Safety and Emergency Management Beijing Normal University Beijing China Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology Southern University of Science and Technology Shenzhen China China Earthquake Administration Key Laboratory of Earthquake Monitoring and Disaster Mitigation Technology Guangdong Earthquake Agency Guangzhou China Guangdong Science and Technology Collaborative Innovation Center for Earthquake Prevention and Disaster Mitigation Guangzhou China Key Laboratory of Disaster Forecast and Control in Engineering of the Ministry of Education Urban Earthquake Safety Laboratory Guangzhou China

Dynamic rupture directivity significantly impacts earthquake hazard and loss assessments; yet, it is often overlooked, leading to uncertainties. We developed high-resolution, broadband, deterministic scenarios for earthquake hazards and losses of the Zhujiangkou Fault (ZF) in the Guangdong-Hong Kong-Macao Greater Bay Area of southern China. The calculations cover the entire physical process from fault dynamic rupture through strong ground motion propagation to quantitative loss estimations. We fully incorporate the real 3D physical fields, including fault structure, regional stress, friction conditions, inhomogeneous velocity, and topography. Results revealed higher earthquake hazards and losses triggered by the northwestern ZF segment, affecting Hong Kong, Shenzhen, Dongguan, Macao, and Guangzhou. The rupture directivity effect, driven by seismic wave interferences in forward propagation, leads to stark differences in hazards and losses across urban agglomerations, even under similar fault conditions. These findings help enhance the precision of earthquake risk assessments and provide practical approaches for disaster prevention.

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Synergically regulated silver species and surface oxygen on manganese oxide for promoted activity of formaldehyde oxidation

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Journal of Environmental sciences 2024年第4期138卷 709-718页

作者： Shuo Hu Jianghao Zhang Xueyan Chen Xiaoxiao Qin Jinshui Yao Changbin Zhang School of Materials Science&Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Formaldehyde(HCHO)is a common indoor pollutant that is detrimental to human *** efficient removal has become an urgent demand to reduce the public health *** this work,Ag-MnO_(x)-based catalysts were prepared and activated under different atmosphere(i.e.,air,hydrogen(H_(2))and carbon monoxide(CO))for efficient oxidation of *** catalyst activated with CO(Ag/Mn-CO)displayed the highest activity among the tested samples with 90% conversion at 100℃ under a gas space velocity of 75,000 mL/(g_(cat)·hr).Complementary characterizations demonstrate that CO reduction treatment resulted in synergically regulated content of surface oxygen on support to adsorb/activate HCHO and size of Ag particle to dissociate oxygen to oxidize the adsorbed *** contrast,other catalysts lack for either abundant surface oxygen species or metallic silver with the appropriate particle size,so that the integrate activity is limited by one specific reaction *** study contributes to elucidating the mechanisms regulating the oxidation activity of Ag-based catalysts.

关键词： HCHO oxidation Ag-MnO_(x)-based catalyst Activation condition Synergic regulation Surface oxygen Oxidized Ag

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