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    25 April 1995, Volume 15 Issue 02 Previous Issue    Next Issue
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    DESIGN AND IMPLEMENTATION OF DIGITIZED PLL SYNTHESIZED SIGNAL GENERATOR
    Zhu Jingmin (Beijing institute of Spacecraft Systems Engineering.Beijing 100086)
    1995, 15 (02):  . 
    Abstract ( 1814 )   Save
    To satisfy the PCM telemetry baseband equipment performance requirements of the ground system of Beijing TTC&M earth station, a new design technique of digitized synthesizer whose output frequency can be changed continuously(resolution:1Hz)is proposed in this paper.The mathod of improving the output signal frequency resolution and stability using PLL technique are mainly described.The idea of"swallow pulse" progranlable dividing frequency and its circuit composition are discussed in detail.The design diagram of PLL is also provided.
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    INTELLIGENT CONTROL IN RENDEZVOUS AND DOCKING
    Yu Sixiang(Beijing institute of Control Engineering, Beijing 100080)
    1995, 15 (02):  . 
    Abstract ( 1511 )   Save
    The intelligent control strategy during automatic homing period and the application of the method of Fuzzy control in the control system designing for the flyaround and final approach stage in rendezvous and docking are discussed in detail in this paper.And the sinulation results which are based on some practical satellite orbit models show that the control strategies proposed in this paperare feasible.
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    AN INFORMATION FILTER FOR THE SATELLITE ATTITUDE DETERMINATION WITH STAR SENSORS
    Li Jie(Beijing institute of Control Engineering, Beijing 100080)
    1995, 15 (02):  . 
    Abstract ( 1662 )   Save
    In this paper an information Filter with Vector Measurements (IFVEM)is presented to cope with the problem in satellite attitude filtering with the vector measurements of star sensors.The analyses show that the IFVEM can process both the single vector measurement and multiple vector measrement in a common frame and simplify the computer program, and it saves computation compared to the conventional Kalman filter.Simulation results are presented to demonstrate the feasibility of the IFVEM in satellite attitude determination.
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    IDENTIFICATION OF STRUCTURAL MODAL PARAMETERS UNDER DRIVEN-BASE EXCITATION
    Sun Zhuqin(Beijing institute of Spacecraft Environment and Engineering,Beijing 100029)
    1995, 15 (02):  . 
    Abstract ( 1922 )   Save
    dentification of structural modal parameters using driven-base excitation is a modal analysis method of practical significance in development of space vehicles.A systematic exploration is presented in this paper.The theoretic Frequency Response Function under driven-base excitation, which is similar to those of tradinon methods, is derived.So the existing modal analysis system can be used to identify modal parameters under driven-base after a little algebraic modification of measured data.It is indicated that the method of driven-base has the same reliability as other traditional methods through computer simulation, cantilever tests and practical application.
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    ALGORITHM RESEARCH OF ORBIT DETERMINATION FOR LOW ORBIT SATELLITES USING GPS
    Liu Bin(Beijing institute of Satellite information Engineering, Beijing 100081)
    1995, 15 (02):  . 
    Abstract ( 1567 )   Save
    The theory and method about determination of spacecrafts orbit using the GPS is discussed detail in this paper.The this includes these aspects:1)the special factors on the constellation selection of the low orbit satellite,2)determination of the orbit using the Least Square method,3)Kalman Filter model composed of nine states for the low orbit satellites.All of these aspect were simulated on the computer AST PA4/33. Baced on the particular raquests of the electrical power and reliability of the user'S satellite,a practical method of the orbit determination is put forword in this paper. According to the results of simulation, the accuracy of the method in this thesis satisfies the user's request.The method can be used in practical application.
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    INFLUENCE OF ARRAY ELASTICITY VIBRATION ON CCD IMAGE
    Zao Yang(Beijing institute of Satellite information Engineering, Beijing 100081)
    1995, 15 (02):  . 
    Abstract ( 1820 )   Save
    In this paper,the dynamical model of a satellite with a large flexible solar array is presented by using Hamilton principles.The satellite CCD photograph model under the effects of orbit motion, earth rotation,earth shape and the Gauss map, etc. is also presented.These models are used to analyse and estimate the influence of the array elasticity vibration on the CCD image geometry quality.
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    DETECTION OF PREAMBLE OF INBOUND SIGNAL IN RDSS SYSTEM
    Xue Li(Xi'an institute of Space Radio Technology.Xi'an 710000)
    1995, 15 (02):  . 
    Abstract ( 1670 )   Save
    In this paper,the fast acquisition system of inbound signal in RDSS system was analyzed theoretically. so the optimum detect system for the preamble and the appoximately optimum detect system were derived. The performance of the appoximately optimum detect system was analyzed.The result of experiment indicated that the theoretical analysis and the test result were indendlcal.
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    MEASUREMENT AND CONTROL SYSTEM AND EXPERAMENT STUDIES OF GAS FLOW STANDARD APPARATUS
    Meng Yang(Lanzhou institute of Physics,Lanzhou 730000)
    1995, 15 (02):  . 
    Abstract ( 1569 )   Save
    In measurement and control system of Gas Flow Standard Apparatus(GFSA),the pressure,volume change and temperature of gas in variable chamber are measured by capacitance diaphragm gauges,grating meters and platinum resistance thermometer.The fluctuation of pressure in variable chamber is controlled within±0.01% by a computer when gas flow is measured. Automatic control and management of GFSA are realized by software.The gas flow in the range of(17.1~1.22)×10-5PaL/s can be measured by GFSA, uncertainty is about 1.93%. Now,reference leaks and gas flowmeters have been calibrated by GFSA.
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    STUDY OF PROGRAMMABLE MULTI-ZONE FURNACE FOR SPACE CRYSTAL GROWTH
    Luo Jun(Lanzhou Institute of Physics,Lanzhou 730000)
    1995, 15 (02):  . 
    Abstract ( 1450 )   Save
    This paper presents the fundamentals of programmable Multizone Furnace for Space Crystal Growth.The most important technology used in the Furnace,i.e.the electro-controlled motion of temperature gradient,is also discussed. On the basis of theoretical analysis,the preliminary research of the Furnace has been done.Some useful results are obtained from the experiments.
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    PRSPECTS OF CHINA SPACE TECHNOLOGY IN THE 21ST CENTURY
    Qi Faren(Chinese Academy of Space Technology,Beijing 100081)
    1995, 15 (02):  . 
    Abstract ( 1805 )   Save
    The objective of China developing space technology is to serve the national economy development.Up to early next century,China intends to set up several stable,operational satellite application systems,including communication and broadcasting,earth observation, natural disaster reduction, microgravity resources,smallsat,etc.;give priority to satellite payload development and bus standerdization;strenghen the R&D of satellite application techniques, strenghen the R&D on advanced technology and basic theory,deepen the imternational exchange and cooperation;begin the feasibility study and advanced technology development for manned space flight and deep space exploration.
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