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    25 October 2004, Volume 24 Issue 05 Previous Issue    Next Issue
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    Motility and Mechanical Analysis of the Hooked Structural Latches with Cam Mechanism
    Liu Zhiquan Cao Peng(China Academy of Space Technology, Beijing 100081)
    2004, 24 (05):  . 
    Abstract ( 1592 )   Save
    The hooked structural latches have been widely used in rendezvous and docking because of their fast motial speed and better self-correcting capability. Static force analysis of the hooked structural latches with cam mechanism during docking maintenance period is carried out. Effect of roughness of docking ring on tension force of the hook is also analyzed. Besides, mechanical analysis of the structural latches is studied on condition that only one group of tightwire work normally. In this paper, a method of inproving engagement capability of structural latches is obtained. Then, the formula of angle at which normal of active hook's mating surface and normal of docking ring's end face lie and the formula of structural latches' load at axial orientation of the docking ring affected by engaging clearance error of structural latches are worked out. Aforementioned results and formula can help designing work.
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    Research on the Analysis Method of Conducted Interference Induced by Space Electrostatic Discharges
    Wang Li Qin Xiaogang Li Kai Ma Yali Huang Liangfu(Lanzhou Institute of Space Technology & Physics, Lanzhou 730000)
    2004, 24 (05):  . 
    Abstract ( 1599 )   Save
    Based on the lumped element models(LEM) analysis method for conducted interference which induced by space electrostatic discharges(SESD), this paper proves the equivalent circuit model for SESD source, and the modeling method for spacecraft structure and cables LEM, are proposed and the conducted interference coupling between SESD and the flat antenna system of a real satellite are analyzed. The results indicate that the LEM analysis method of SESD conducted interference is a useful tool for SESD protecting and evaluating in spacecraft engineering.
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    On Geometric Description Algorithm of Spacecraft Shielding or Masking
    Pei Yang Song Bifeng Li Zhanke(Northwestern Polytechnical University, Xi'an 710072)
    2004, 24 (05):  . 
    Abstract ( 1449 )   Save
    An algorithm providing the spacecraft geometric description for vulnerability assessment is proposed. The original model preparation for the algorithm may be approximated by a series of cylinder, sphere, and cube segments, or by reading quadrilateral finite elements from finite element data files built in MSC/PATRAN. The basic principle to calculate projected area, overlapping area from any aspect considered is shown in this paper, which uses the vertical scanning line and shot line methods. The intersection points of shot line and quadrilateral finite elements in the overlapping area are recorded to determine the masking/shielding among components. The proposed algorithm has been programmed to offer the sufficient detailed target description and application shows that it can deal with any muti-overlapping among components and the error can be reduced through shortening the step length.
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    Primary Analysis of the Solar Activities During Carrington Rotation 2009
    Le Guiming(Center for Space Science and Applied Research, Beijing 100080)
    2004, 24 (05):  . 
    Abstract ( 1782 )   Save
    The solar activities produced by active regions 484, 486 and 488 and the impacts on space environment produced by these solar activities are introduced. The difference among the three huge sunspot groups are studied briefly based on the statistical study on solar activities. The results show that active longitude band and main hemisphere of solar activity are very important information for the short term prediction of solar activity.
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    Guidance Strategy Design for the Final Translation of Space Rendezvous
    Zhu Renzhang Yin Yan(Beijing University of Aeronautics and Astronautics, Beijing 100083)
    2004, 24 (05):  . 
    Abstract ( 1549 )   Save
    The design method of the guidance strategies for the final translation of space rendezvous is investigated in this paper. In the final translation, the chaser makes straight line forced motion with a give relative velocity profile, in terms of which the maneuver acceleration can be derived, and N-thrust and multi-pulse propulsion can be used in engineering projects.
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    Research on Algorithm of Loopy Lambert Transfer in Space Rendezvous
    Han Chao Xie Huawei(Beijing University of Aeronautics and Astronautics, Beijing 100083)
    2004, 24 (05):  . 
    Abstract ( 1972 )   Save
    A basic problem of spaceflight dynamics named Gauss problem is how to determine the orbit by the information of the two positions and flight time. The problem of Lambert rendezvous is the embodiment of Gauss problem in the field of spacecraft rendezvous. This paper issues a new algorithm, which can solve the problem about loopy Lambert transfer of spacecraft. Then the result is applied to search for the orbit of Lambert transfer of spacecraft whose fuel penalty is optimal under the condition of long-time flight. The calculation results validate the correctness and robustness of the algorithm.
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    Analysis of the Parameters in Space Debris Environment Engineering Model
    Tang Qi Pang Baojun Zhang Wei(Harbin Institute of Technology, Harbin 150001)
    2004, 24 (05):  . 
    Abstract ( 1550 )   Save
    To assess the damage to spacecraft from space debris, the space debris environment engineering model must be estabilshed. At first, this paper introduces the characteristics of the space debris environment and the describing method of engineering model. Then analysis and compares the parameters of several primary space debris environment engineering model. At last, in view of the mathematical model and application in the risk assessment, a scheme of interface parameters of space debris environment engineering model code is provided.
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    Flowing/Heat Transfer Analysis of A Parallel-style CPL/LHP Condenser
    Liu Qingzhi Hou Zengqi(China Academy Space Technology, Beijing 100086)
    2004, 24 (05):  . 
    Abstract ( 1618 )   Save
    Two kinds of layout of condenser pipes in deployable radiator of spacecraft are compared and analyzed. Calculation and analysis of flow/heat transfer of two-phase working fluid in a parallel-style condenser are performed under microgravity conditions with SINDA/FLUINT code. It is found that the throttling pipes behind condenser have great effect on the position of vapor/Iiquid interface in condenser pipes, which provides a reference for condenser design and improvement of radiator performance.
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    An Intelligent Autonomous Control System for Minisatellite Systems and Constellations
    Qin Shiyin Yan Fei(Beijing University of Aeronautics and Astronautics, Beijing 100083)
    2004, 24 (05):  . 
    Abstract ( 1556 )   Save
    With the development of technologies for minisatellites and constellations, the mode of the control and management system for minisatellite systems and constellations is evolving towards a new type of intelligent and autonomous ones from the traditional control and management sytem which is mainly governed by the ground control station. In this paper, some features and potentials of minisatellite systems and constellations are detailed at first, then the necessity and advantages as well as the technical feasibility of implementing intelligent autonomous control and management are discussed in depth, then based on the organic combination of hybrid control system (HCS) theory with multi-agent system (MAS) technology a kind of architecture of intelligent autonomous control system for minisatellite systems and constellation is proposed, which is characterized by high level autonomy, flexibility and reliability in its performances. At the same time, the synthetic optimizing design strategy and algorithms for this kind of autonomous intelligent control system are studied. At last with such an organizing architecture and corresponding control strategies, a computer simulation for the intelligent and autonomous orbit keeping of the formation flight for a satellite group that includes two minisatellites is presented and the result is satisfactory.
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    Research and Analysis of Hyperspectral Remote Sensing Image Dimensional Reduction
    Zhao Chunhui Liu Chunhong(Harbin Engineering University, Harbin 150001)
    2004, 24 (05):  . 
    Abstract ( 1737 )   Save
    With the development of spectrometer, the research of hyperspectral remote sensing image has come into a new stage-processing and utilizing the acquired image efficiently. Now many processing methods are centered on arithmetic analysis processing of hyperspectral, such as atmosphere correction, dimensional reduction, information extraction, classification, compression, and so on. Whereas dimensional reduction of hyperspectral image is an important step to continue subsequent procedure. To select a dimensional reduction method correctly will affects the arithmetic and software which deal with plenty of data and abundant information of hyperspectral image. This paper generalizes and analyzed various methods from the point of view of band selection, subspace decomposition, feature extraction and fusion both at home and abroad.
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    Proof and Deduction of an Attitude Updating Algorithm Used in Strapdown Inertial Navigation
    Kang Shuai Pang Huawei Zhou Weilin(National University of Defensive Technology, Changsha 410073)
    2004, 24 (05):  . 
    Abstract ( 1549 )   Save
    The calculation of attitude updating is one of the key problems in strapdown inertial navigation system. In this paper a new and high accurate attitude updating algorithm, the four- order Taylor espansion method, is propounded, and the mathematical proof and deduction of that are showed The studyeffors important and powerfully effective reference for developing SINS algorithm.
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