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    25 December 2009, Volume 29 Issue 06 Previous Issue    Next Issue
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    Analysis and Implement of Determining the Orbit Maneuver Effect of CE-1 Satellite
    Tang Geshi1,2 Chen Lidan2 Liu Yong2(1 Beijing University of Aeronautics and Astronautics,Beijing 100191)(2 Beijing Aerospace Flight Control Center,Beijing 100094)
    2009, 29 (06):  1-6+14. 
    Abstract ( 2170 )   Save
    The orbit maneuver accuracy of the satellite can be greatly improved by determining the maneuver effect.A method of calibrating the effect of control engines and accelerometer scale error by using the precise orbit parameters,telemetry data for attitude and accelerometer was produced.Then,the successful application of this method to the Chinese first lunar prospector mission was presented.Finally,the sensitivity of the calibrating result to the accuracy of orbit and attitude determination was analyzed.The results prove that the calibration of control effect is feasible,and also very important to deep space exploration in future.
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    Forgetting Factor Algorithm for Aircraft Flutter Modal Parameter Identification
    Wang Jianhong Wang Daobo Wang Zhisheng(College of Automation Engineer,Nanjing University of Aeronautics and Astronautics,Nanjing 210016)
    2009, 29 (06):  7-14. 
    Abstract ( 1759 )   Save
    A novel frequency-domain subspace system identification based on forgetting factor was discussed.The key idea was applied for frequency-domain MIMO state-space models starting from frequency response function data and generalized by taking into account the initial and final conditions.It was necessary to guarantee leakage-free effect calculated through the discrete Fourier transform.A forgetting factor was introduced in the Hankel matrices of the input-output data to increase the convergent rate.In order to solve the system matrices problem,principle component analysis was used to determine the system observability subspace matrices and achieve consistent estimates of the system matrices.Before applying the algorithm,the innovation variance criterion was used to estimate the system′s order in order to decrease the complexity.The efficiency of this method was illustrated with a simulation example.
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    Research on Calculation Method of Dynamic SNR of TDICCD Camera
    Ruan Ningjuan Su Yun Zhang Keke Li Bo(Beijing Institute of Space Mechanics & Electricity,Beijing 100076)
    2009, 29 (06):  15-20. 
    Abstract ( 2185 )   Save
    The SNR is one of the primary parameters in optical sensor system,which can be used to reflect radiation performance of remote sensor.The orbit model of the remote sensing satellite was built,then the solar angle and observer angle,which were used to describe the relative position of the sun,the satellite and objects,were input into the air transmission software MODTRAN,the spectral radiance calibration was output by this model,and the real time SNR of TDICCD camera was completed.By the proposed method,dynamic SNR at any time and for any observation objects can be calculated,which will help to estimate whether the energy is enough for observation.The result is used to change the level of TDICCD to make the image quality best.
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    Federated SSUKF for Multi-sensor Spacecraft Attitude Estimation
    Fan Chunshi1 Zhang Gaofei2 Sun Jian2 Meng Ziyang1 You Zheng1(1 Department of Precision Instruments and Mechanology,Tsinghua University,Beijing 100084)(2 State Key Laboratory of Precision Measurement Technology and Instruments,Tsinghua University,Beijing 100084)
    2009, 29 (06):  21-27+80. 
    Abstract ( 1776 )   Save
    A federated version of spherical simplex unscented Kalman filter(SSUKF) waspresented for space-borne orbit debris surveillance mission.The nonlinear transformation filtering method brought the algorithm a high precision,while the reduced sigma point filtering technique endowed the algorithm with a high computing speed,and the decentralized structure ensured the algorithm a good capability of reconstruction in case of sensor fault or vision limit.A filtering system composed of gyroscopes,magnetometer,sun sensor and star tracker was designed using this algorithm,and was validated with numerical simulation.
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    Method for Calculating the Active Element Pattern of the Phased Array Antennas
    Du Hailong Yan Lubin (China Academy of Space Technology,Beijing 100094)
    2009, 29 (06):  28-31. 
    Abstract ( 2104 )   Save
    Based on the Floquet's principle,methods of determining the active element pattern of infinite phased array antennas were proposed,comparing with the comventional method,the method can be used to not only calculate the active element power pattern but also calculate the active element field pattern.So more radiation information such as cross-polarization levels,phase information can be obtained.The comparison between numerical results and simulation results shows these methods are feasible.
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    Research on Dynamics Modeling of the Lunar Soft-Landing Explorer
    Tian Hao Bai Zhengfeng Zhao Yang(Harbin Institute of Technology,Harbin 150001)
    2009, 29 (06):  32-38+44. 
    Abstract ( 1882 )   Save
    The propellant tank of the Lunar soft-landing explorer adopts lateral symmetry dispersible layout,and the effects of the layout on the liquid propellant sloshing were analyzed.Liquid in the tank was considered as the first-order spring mass model,and the dynamics model ofLunar soft-landing explorer including propellant shake was established by using virtual power principle and the dynamics model was applicable from the dynamics descending stage to the landing stage.Finally,the dynamics simulation of descending stage was made and the simulation results can provide theory reference for explorer control system design.
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    Influences Analysis of Moon Surface Terrain on the Rover Antenna Direction
    Li Qingyi(Beijing Institute of Spacecraft System Engineering,Beijing 100094)
    2009, 29 (06):  39-44. 
    Abstract ( 1813 )   Save
    A kind of simulation method was introduced to simulate the moon rover static & mobile measurement and control(TMTC) status including azimuth and elevation.The method covered immobile and locomotive status with and without terrain.Theoretical azimuth and elevation of landing point were given and compared with Satellite tool kit(STK).Considering a kind of virtual moving route,the influence of given terrain on the rover TMTC status was worked out.
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    Satellite Attitude Estimation Using MRPs Based on UPF
    Mou Zhongkai Sui Lifen Huang Xianyuan(Institute of Survey and Mapping,Information Engineering University,Zhengzhou 450052)
    2009, 29 (06):  45-51. 
    Abstract ( 1773 )   Save
    Based on particle filtering(PF),unscented particle filter(UPF)was proposed for satellite attitude estimation based on modified rodrigues parameters(MRPs) and dynamic equation for attitude representation and the propagation of angular velocity respectively.The unscented kalman filter(UKF) was used to generate sophisticated proposal distributions,which can take advantage of the latest measurements.The simulation results show that the presented method has higher accuracy than that of the standard PF and UKF.
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    Study of Fault Detection Method for 3+1S Gyro Unit
    Wang Lifeng Yang Hui Wang Jingang(China Academy of Space Technology,Beijing 100094)
    2009, 29 (06):  52-58. 
    Abstract ( 1642 )   Save
    The angular rate saturation which the angular rate of spacecraft goes beyond the measurement range of gyroscopes was researched.The countermeasure for the miscarriage of justice based on the base of fault mode analysis was presented.The threshold of parity equation from the engineering point of view was also comfirmed and also improved parity equation was improved.The result of simulation indicates that the improved parity equation can not only detect the break fault in time but also can shorten the delay time when the slow fault such as the drift of gyroscopes is detected.
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    Analysis and Verification of CCSDS SCPS-NP and SCPS-TP Protocol
    Liu Jun Wang Jiulong Shi Jun(China Academy of Space Technology,Beijing 100094)
    2009, 29 (06):  59-65. 
    Abstract ( 2773 )   Save
    According to the characteristics of space communications,the Consultative Committee for Space Data Systems(CCSDS)developed SCPS(Space Communications Protocal Specification) protocol set.The application of CCSDS recommendations in China,and the practical application of CCSDS SCPS protocol in network layer(SCPS-NP) and Transport Protocol(SCPS-TP) were introduced,characteristics and applicability were analyzed.It was also compared with TCP/IP protocol for contrast,finally design the program verification system to verify the proposal.The results show that for space communications in specific circumstances,the use of SCPS protocol is superior to that of TCP/IP protocol.
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    Simple Tension Control Strategy for Variable Length Tethered Satellite System
    Zhong Rui Xu Shijie(School of Astronautics,Beihang University Beijing 100191)
    2009, 29 (06):  66-73. 
    Abstract ( 2053 )   Save
    In order to simplify the control of tethered satellite system(TSS),a new design method was proposed by upgrading the existing methods.A linear autonomous system was established according to the dynamic functions of TSS and a linear feedback control law was derivate from this system for deployment,station-keeping and retrieval phases in the same process.Then the parameters of the control law were discussed.For retrieval phase,a piecewise retrieval law was derived by designing the equilibrium point parameter.Numerical simulation results prove that the method works well for the three phases of TSS mission in both circular and near circular orbits.
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    In-orbit Calibration Methods of Accelerometer Parameters on Satellite-borne Gravimetry
    Zhou Zebing1 Bai Yanzheng1 Zhu Zhu1 Zhang Xiaomin2(1 School of Physics,Huazhong University of Science and Technology,Wuhan 430074)(2 DongFangHong Satellite Co.Ltd.,Beijing 100094)
    2009, 29 (06):  74-80. 
    Abstract ( 1988 )   Save
    The operation principle of the electrostatic space accelerometer was introduced,and the calibration methods of the accelerometer parameters in-orbit for the present Earth's gravity field survey missions were outlined.The feasibilities of the methods which are executed by the means of the thrust forces,the centrifugal forces due to the satellite rotation motions,and the gravitation forces,to determine the scale factor of the accelerometer in-orbit,were analyzed.
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