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    25 August 2003, Volume 23 Issue 04 Previous Issue    Next Issue
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    Research on 3D Attitude Determination System Based on GPS
    Zheng Qinghui (College of Aerospace and Material Engineering, National University of Defense Technology Changsha 410073) Zhang Yulin Zeng Guoqiang Liu Youming (College of Arming and Commanding Technic,Beijing 101416 )
    2003, 23 (04):  . 
    Abstract ( 1637 )   Save
    A 3D attitude determination system is established. Theory and algorithm of attitude determination based GPS are addressed in this paper. Least square adjustment is used to calibrate baseline, then get baseline length and angle between two baselines, which can be used as a restriction to accelerate ambiguity resolution. Vector of baseline is estimated to get coarse attitude, ultimately, the precise attitude is estimated by iterative least square adjustment. All the discussed above are validated by attitude determination system.
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    Research of INS/SAR Integrated Navigation System Aided by Height
    Xiong Zhi Liu Jianye Lin Xueyuan (Navigation Research Center, Nanjing University of Aeronautics & Astronautics Nanjing 210016)$$$$
    2003, 23 (04):  . 
    Abstract ( 1943 )   Save
    The theory of terrain-aided navigation system has been presented, which is based on the matching of SAR images. The SAR images aided navigation can't get the information of height, so the height output is be added to the system, and the block diagram is given. Built the equations of integrated navigation system and perform the simulation. Simulation result shows that the accuracy of the system can be improved greatly, and the design of the system is feasible.
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    Empirical Layered Correction Algorithm for Refractive Error of Radar Signals
    Hu Shaolin (University of Science & Technology of China, Hefei 230027) Niu Xiaolei Xu Aihua Chai Min (Xi′an Satellite Control Center, Xi'an 710043)$$$$
    2003, 23 (04):  . 
    Abstract ( 1807 )   Save
    A new algorithm is built for correcting refractive error of radar signals, which is called the empirical layered correction in this paper Based on comparing with the empirical correction and the layered correction, it can be found that this new with the highest precision This new algorithm can be used in case that there are no weather stating exists to measure refractive parameters of atmosphere and can improve the precision of measurement and control of spacecraft
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    Numerical Simulation Study on the Pulse Tube Cryocooler for Space Application
    Ma Jun (Beijing University of Aeronautics and Astronautics, Beijing 100083) Hou Yukui (Chinese Academy of Space Technology, Beijing 100081) Ju Yonglin Zhou Yuan (Technical Institute of Physics and Chemistry, Beijing 100080)
    2003, 23 (04):  . 
    Abstract ( 1523 )   Save
    Having no moving part in the low temperature region of the cold finger, the pulse tube cryocooler has considerable system advantages over most other types of regenerative refrigerators in terms of simplicity, reliability and vibration It is a innovative cryocooler for space application In this paper, the 1-dimensional model describing the nonlinear process within the pulse tube cryocooler is solved using finite difference method The simulation results are compared with the experiment results.
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    Calculation for the Impulse of Micro-Detonation Thruster
    He Yuanhang(Beijing Institute of Technology, Beijing 100081) Wang Ping(CDSTIC, Beijing 100036)
    2003, 23 (04):  . 
    Abstract ( 1649 )   Save
    The lightweight micro detonation thruster is consisted of a lot of thrust units containing tiny energetic material By using the instantaneous detonation assumption and the tiny charge mass linear approximation, the impulse and the thrust of a micro detonation thrust unit operating in vacuum are theoretically calculated in this paper Based on that, the influences of specific detonation heat, isentropic exponent and length of the nozzle on the impulse and the thrust are studied The results show that increasing the charge mass, the isentropic exponent and the specific detonation heat can enhance the impulse of a thrust unit, and the nozzle length must be 4 times or more of the charge length to achieve the perfect propulsion performance
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    The Stability and Accuracy Analysis of Ballistic Estimating with Position and Range Rate Fusion
    Zhu Zhuanmin Yang Yikang Huang Yongxuan (System Engineering Institute of Xi'an Jiaotong University, Xi'an 710049) Li Jisheng (Xi'an Satellite Control Centre, Xi'an 710043)$$$$
    2003, 23 (04):  . 
    Abstract ( 1549 )   Save
    Based on the Kalman filter, the paper discusses the influence factors on robust and estimate accuracy when rebuilt the ballistic, and demonstrates the range rate data functions in rebuilding the ballistic strictly. The analysis and simulation demonstrates that using the velocity and position data simultaneously is one of the basic ways to improved the sysem's stability and data processing quality
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    Research on Small Satellite Formation Reconfiguration Control
    Wei Juan * Ning Fangli ** Huang Yongxuan * (*Institute of System Engineering, Xi'an JiaoTong University, Xi'an 710049) (**College of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072)
    2003, 23 (04):  . 
    Abstract ( 1502 )   Save
    In this paper, 6DOF control of formation flying for formation reconfiguration is studied Firstly, rotation and translational motion model is established Then translational motion rale is designed mainly using robust control theory, the controller for closed loop system is obtained Finally, the correctness of the method is exemplified, the simulating result shows that the method is effective and feasible
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    Reliability Analysis of Special Type of Redundant Inertial Attitude Reference System on Board
    Yun Ben (Beijing Institute of Control Engineering, Beijing 100080)
    2003, 23 (04):  . 
    Abstract ( 1745 )   Save
    With the development of space technology, components on satellites and spacecrafts are becoming more and more complicated, there is a need of more simple applicable redundant scheme and reliability analyzing method for engineering application. A new approach for a special kind of redundant system is proposed, which is applied in redundant inertial attitude reference system on satellites. It is a new redundant scheme that takes K out of N redundant system and cold store redundant system. It is proved that scheme is ready for engineering practice in theory.
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    Research on Integrated Vehicle and Ground Fault Diagnosis System for Space Laboratory
    Long Bing Fan Xianfeng Jiang Xingwei Jing Wuxing (Harbin Institute of Technology, Harbin 150001) Li Zhi (Chinese Academy of Space Technology, Beijing 100086)$$$$
    2003, 23 (04):  . 
    Abstract ( 1966 )   Save
    Research on fault diagnosis for spacecrafts is not only helpful to improve the safety and reliability of spacecrafts, but also to reduce their life cycle cost significantly. An Integrated Vehicle and Ground Fault Diagnosis System for space laboratory is described in detail. The system is consisted of Integrated Vehicle Fault Diagnosis System (IVFDS) with limited autonomous diagnosis capability, and Integrated Ground Fault Diagnosis System (IGFDS) including diagnosis system level fault and subsystem level fault. Model based reasoning (especially for multi signal model) is emphasized in this system. At the end of this paper, it is pointed on that some key techniques such as system modeling and component based diagnosis system, need to be studied in depth.
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    Influence on Launching Azimuth by Launching Point Position Error
    Duan Xiaojun Yao Jing Zhou Haiyin (National University of Defense Technology, Changsha 410073)$$$$
    2003, 23 (04):  . 
    Abstract ( 1602 )   Save
    This paper analyzes the influence on launching coordinates of ballistic missile produced by launching point position error. The change lies not only in original point but also in Eulerian angle of coordinate transformation. Therefore, based on the geometric principle of plane equation being determined and Cosine formula to calculate the angle of two planes, a simple analytical expression among launching azimuth, launching point and goal point are obtained firstly in the Earth centered Inertial coordinates. Secondly, by the aid of Earth centered Inertial coordinates , the transformation matrix between the launching coordinates with error and the true one is derived. Given the launching point and the goal, the influence on launching coordinates of ballistic missile produced by launching point orientation error can be achieved in quantified value.
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    Theoretical Analysis of Thermal Contact Resistance Between Solid Interfaces
    Zhao Lanping (Tongji University, Shanghai 200092) Xu Lie (Department of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030)$$$$
    2003, 23 (04):  . 
    Abstract ( 1755 )   Save
    A new fractional thermal contact conductance (TCC) model based on fractional geometry , the M T model and classical thermal contact theory which includies bulk resistance and also constriction resistance is developed. The relation between TCC values and the affecting factors such as the contact pressure, the fractal roughness, the material properties and the interface temperature is derived from this model.
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    Fault Diagnosis and Optimizing Configuration of Flywheels Based on Direct Redundancy
    Xing Yan (Beijing Institute of Control Engineering, Beijing 100080)$$$$
    2003, 23 (04):  . 
    Abstract ( 1659 )   Save
    Fault detection and diagnosis of closed loop control system is one of the problems in urgent need of solving in satellite control engineering. Fault of one actuator in closed loop system will affect the outputs of other normal actuators because of fault propagation. Flywheels are main actuators of satellite control system in long term orbitmove mode and faults are unavoidable owing to their continuous mechanical movement. The fault would have a strong impact on the satellite if it can not be detected and isolated in time. This paper presented a fault detect and isolate method based on the direct redundancy of flywheels, its basic idea is that there exists consistency of the flywheels′ outputs (change rate of rotation rate) in redundant configuration flywheels system, and inconsistency in the measured rotation rates is then ametric that can be used for detecting faults and subsequently for fault isolation. This method didn′t need to integrate the torque control command of every flywheel and reduced calculation amount. Simulation results showed that this method could detect and isolate incipient fault in real time. At last we made optimizing configuration analysis of the direct redundant flywheels from the fault detect performance point of view.
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    B-Spline Wavelets Edge Detection with Embedded Confidence
    Yan Fengxia Luo Jianshu (National University of Defense Technology, Changsha 410073)$$$$
    2003, 23 (04):  . 
    Abstract ( 2186 )   Save
    In edge detection, matching with a template derived from the input data is meaningful since it provides an independent measure of confidence in the presence of the employededge model. In this paper, by making good use of the characteristics of wavelet transform and multi scale of edge information, the cubic B spline smoothing filter operator is designed and combined with the embedded confidence to detect edges. Furthermore, the edge detection method for those images badly contaminated by noises is studied, according to the sensitivity of human visual system. The experimental results show that the proposed method can detect the edges of images accurately and efficiently.
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