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International Symposium on Antennas Propagation and EM Theory

作者： H. Zhao L. X. Guo J. Ma School of Science Xidian University Science and Technology on Space Simulation Laboratory Beijing Simulation Center

ISBN: (纸本)9781467317993

In this paper, the physical optical (PO) method is employed to calculate the electromagnetic field distribution on the seeker antenna when the missile approaches the target. Compared with the result calculated in the millimeter wave simulation system (MMWSS), it can be equivalent to one or more scattering points when the target is located in the far-field of antenna.

关键词： physical optics missiles ANTENNA antennae Targets field distribution far-field broadcasting Scattering seekers Equivalent simulation systems millimeter wave

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space science Mission Operation system joint test method research

Space Science Mission Operation System joint test method res...

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12th International Conference on space Operations, spaceOps 2012

作者： Wu, Haiyan Meng, Xin Zhang, Yuzhu Zou, Zimin Tong, Jizhou Xiaodong, X. Li, Dalin Center for Space Science and Applied Research Chinese Academy of Science Beijing 100190 China Graduate University Chinese Academy of Science Beijing 100049 China Space Information and Simulation Laboratory 8701 Beijing China Data and Net Center 8701 Beijing China

Testing is important for space science Satellite Ground Application system (SSSGAS) development, which usually takes a lot of time. This paper introduces a system Joint Test Platform that could be applied to SSSGAS's development, testing and verification. SJTP's purpose is to check whether SSSGAS's various subsystems and functional module interface is in line with the system interface specification so to reduce the workload of system testing. SJTP can simulate SSSGAS's various subsystems or functional module interface functions and processes in order to do debugging with the measured subsystem / function module interface;it can also simulate and test the system's process by connecting with one or more of the actual subsystem / functional modules together to emulate the complete SSSGAS. © 2012 by center for space science and Applied Research, Chinese Academy of sciences.

关键词： Testing

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Application of high frequency scattering predication method in MMWSS

Application of high frequency scattering predication method ...

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International Conference on Microwave and Millimeter Wave technology Proceedings

作者： J. K. Nie L. X. Guo H. Zhao J. Ma J. D. Fei School of Science Xidian University Xi'an Shaanxi China Key Laboratory on Space System Simulation Beijing Simulation Center Beijing China

A radiation model of millimeter wave antenna is established in this paper. The electromagnetic field distribution on the seeker antenna is calculated in MMWSS based on PO method. According the numerical results, when target is in the near-field of antenna, the characteristic of echo amplitude has an obvious effect of multi-scattering points effect.

关键词： Missiles Scattering Surface waves Antenna radiation patterns Mathematical model Millimeter wave technology

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Static simulation scheduling for the validation of space system requirement decomposition

Static simulation scheduling for the validation of space sys...

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63rd International Astronautical Congress 2012, IAC 2012

作者： Zhang, Hao Gerndt, Andreas Liu, Bo Simulation and Software Technology Braunschweig Germany Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Graduate School of Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781622769797

One important issue in space engineering is to ensure that all system requirements arc always fulfilled throughout the whole development process. To perform this task, various validation technologies have been developed. In this paper, document-based reviews and Modelling & simulation technology are illustrated as two of such technology examples. Their disadvantages are analysed as well. The fundamental challenge for them is to carry out a consistent validation throughout the whole development process. To resolve this problem, a static simulation scheduling approach is proposed in this paper. This scheduling approach is based on a hierarchical decomposition model of a space system. The model is constructed following the principles of Model-Based systems Engineering (MBSE). It maps all requirements to state variables and defines states as well as relations along three red lines of a space mission: inter-subsystems, internal subsystems, and space mission lifecycle. In the static simulation scheduling approach, the validation is driven just by the states of state variables and their relations. But, the specific validation process is dependent on current states of the processed variable. The scheduling approach is illustrated and demonstrated in this paper. It facilitates a preliminary validation analysis throughout the whole development lifecycle that would otherwise be cost intensive or even be impossible. Furthermore, after each system refinement, the validation analysis can be performed again automatically. Our work is based on the "Virtual Satellite", which is being developed by German Aerospace center (DLR). We are pursuing the possibility to implement specification, analysis, design, and operation of space missions in a unified framework.©2012 by the International Astronautical Federation.

关键词： Scheduling

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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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Soft-switching analysis of a resonant capacitor current feedback self-oscillating inverter

Soft-switching analysis of a resonant capacitor current feed...

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2012 IEEE 7th International Power Electronics and Motion Control Conference - ECCE Asia, IPEMC 2012

作者： Shao, Mingsong Huang, Songling Zhao, Wei Wang, Changquan State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing China Lighting Research Center Century Zhuoke Energy and Technology Co. LTD Beijing China

ISBN: (纸本)9781457720864

In this paper, we examine a resonant capacitor current feedback (RCCF) self-oscillating resonant inverter from nonlinear point of view. By adopting a four-stage equivalent model, we derive the soft-switching dead time from time-domain for the series resonant capacitor linked parallel load circuit. Importantly, we propose a nonlinear model for the current feedback and gate-drive circuit. Based on analyzing the switching transition interval of this model, the determination of feedback parameters is inferred with given input power and resonant elements. Experimental results have been obtained for a RCCF self-oscillating inverter operating at 3 MHz and 300 V bus voltage. © 2012 IEEE.

关键词： Feedback

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3D state decomposition modeling method for MBSE in space engineering

3D state decomposition modeling method for MBSE in space eng...

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AIAA space Conference and Exposition 2012

作者： Zhang, Hao Gerndt, Andreas Liu, Bo Simulation and Software Technology Lilienthalplatz 7 Braunschweig 38108 Germany Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China Graduate School of Chinese Academy of Sciences Beijing 100190 China Center for Space Science and Applied Research Chinese Academy of Sciences NO.1 Nanertiao Zhongguancun Haidian district Beijing 100190 China

ISBN: (数字)9781600869402

ISBN: (纸本)9781600869402

The increasing number of space missions and the market environment make it mandatory that the design process and design models have to be reused in future space missions. As a solution to such a reuse problem, Model-Based systems Engineering (MBSE) is highly recommended. Since constructing a model is the first step to reach MBSE, a 3D state decomposition modeling method is proposed in this paper. Starting from Technical Requirements (TRs), the method maps them to state variables and defines states as well as relations along three red lines of space engineering: internal subsystem, inter-subsystems, and space mission lifecycle. Eventually, it yields decomposition of a space system into a hierarchical three-dimensional model of states. Relying on the Eclipse Modeling Framework (EMF), the model can be described and stored in a standardized format, which allows the reuse of once defined models in subsequent space missions. This study leads to a novel MBSE solution to implement specification, analysis, design, and operation of space mission systems in a unified framework. © 2012 by Hao Zhang, Andreas Gerndt, Bo Liu. Published by the American Institute of Aeronautics and Astronautics, Inc.

关键词： systems engineering

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Rate-distortion weighted SPIHT algorithm for interferometer data processing

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Journal of systems Engineering and Electronics 2011年第4期22卷 547-556页

作者： Jing Ma Jindong Fei Dong Chen Science and Technology on Space Systems Simulation Laboratory Beijing Simulation Center Beijing 100854 E R. China Institute of Telecommunication Satellite China Academy of Space Technology Beijing 100094 P. R. China

As one of the next generation imaging spectrometers, the interferential spectrometer （iS） possesses the advantages of high throughput, multi-channel and great resolution. The data of IS are produced in the spatial domain, but optical applications are in the Fourier domain. Traditional compression methods can only protect the visual quality of interferometer data in the spatial do- main but ignore the distortion in the Fourier domain. The relation between the distortion in the Fourier domain and the compression in the spatial domain is analyzed. By mathematical proof and val- idation with experiments, the relation between spatial and Fourier domains is discovered, and the significance in the Fourier domain is more important as optical path difference （OPD） increasing in the spatial domain. Based on this relation, a novel coding scheme is proposed, which can compress data in the spatial domain while reducing the distortion in the Fourier domain. In this scheme, the bit stream of the set partitioning in hierarchical trees （SPIHT） is truncated by adaptively lifting rate-distortion slopes according to the priorities of OPD based on rate-distortion optimization theory. Experimental results show that the proposed method can provide better protection of spectrum curves in the Fourier domain while maintaining a comparable visual quality in the spatial domain.

关键词： interferential spectrometer （IS） multi-spectrum compression set partitioning in hierarchical trees （SPIHT）.

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Lateral jet interaction model identification based on genetic programming

Lateral jet interaction model identification based on geneti...

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3rd International Conference on Artificial Intelligence and Computational Intelligence, AICI 2011

作者： Chen, Shi-Ming Dong, Yun-Feng Wang, Xiao-Lei School of Astronautics Beijing University of Aeronautics and Astronautics Beijing China Science and Technology on Space System Simulation Laboratory Beijing Simulation Center Beijing China

ISBN: (纸本)9783642238802

Precise lateral jet interaction models are required for missiles' blending control strategies. Because of the complicated flow field, the interaction models are multivariable, complex and coupled. Traditional aerodynamics coefficients model identification used Maximum-likelihood estimation to adjust the parameters of the postulation model, but it is not good at dealing with complex nonlinear models. A genetic programming (GP) method is proposed to identify the interaction model, which not only can optimize the parameters, but also can identify the model structure. The interaction model's inputs are altitude, mach number, attack angle and fire number of jets in wind channel experiment results, and its output is interaction force coefficient. The fitness function is root mean square error. Select suitable function set and terminal set for GP, then use GP to evolve model automatically. The identify process with different reproduced probability;crossover probability and mutation probability are compared. Results shows that GP's result error is decrease 30% than multi-variable regression method. © 2011 Springer-Verlag.

关键词： Missiles

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Creating pentamer molecules by generalized stimulated Raman adiabatic passage

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Physical Review A 2012年第2期85卷 023629-023629页

作者： Fu-Quan Dou Sheng-Chang Li Hui Cao Li-Bin Fu School of Physics Beijing Institute of Technology Beijing 100081 China Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province College of Physics and Electronic Engineering Northwest Normal University Lanzhou 730070 China National Laboratory of Science and Technology on Computation Physics Institute of Applied Physics and Computational Mathematics Beijing 100088 China Key Laboratory of High Energy Density Physics Simulation Center for Applied Physics and Technology Peking University Beijing 100084 China

We study the formation of stable homonuclear and heteronuclear pentamers from ultracold atoms via a generalized stimulated Raman adiabatic passage scheme. The atom-molecule dark-state solutions for the system are obtained, and the linear instability and the adiabatic fidelity of the dark state are investigated. We also discuss the effects of external field parameters on the conversion efficiency.

关键词： ULTRACOLD molecules RAMAN effect ATOMIC theory ADIABATIC processes PARAMETER estimation ENERGY conversion

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