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  • Accurate Algorithm for Trajectory Determination of Launch Vehicle in Ascent Phase
  • GUO Jun hai, ZHAO Hua
  • 2015, 36 (9): 1018-1023. doi: 10.3873/j.issn.1000-1328.2015.09.006
  • Abstract ( 472 ) PDF (743KB)( 26528 )

    For the problem of trajectory modeling in ascent phase of launch vehicle, free-node spline model is proposed to represent the change of this trajectory. The trajectory parameter estimation is converted to spline function coefficient estimation for trajectory determination, thus effectively improving accuracy by reducing the number of estimated parameters. Furthermore, an algorithm for optimization of measurement elements is obtained to improve accuracy of the trajectory determination by using chromosome encoding of measurement elements, constructing fitness function based on weighted ranking and designing the improved proportion selecting operator in basic genetic algorithm frame. Then the combinatorial space of measurement elements is sufficiently searched for optimization. The results of simulation based on the classical trajectory of ascent phase and distribution of stations show that accuracy of ascent trajectory determination is effectively improved. Compared with traditional methods, position determination accuracy of this method is improved from 92.0% to 94.4%. In the case of using free-node spline model, the position determination accuracy is also enhanced to 16.4%~ 88.6%.

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  • A Evaluation Method for Multi Spacecraft Formation Detection Efficiency
  • YANG Zhen, MENG Xin, NIU Wen long, LI Ming tao, ZHANG Yi teng, ZHENG Wei
  • 2015, 36 (9): 981-987. doi: 10.3873/j.issn.1000-1328.2015.09.001
  • Abstract ( 277 ) PDF (1824KB)( 21778 )

    In order to choose the best detection efficiency of different formations, quantitative evaluation of different formations shall be employed. In this paper, the existing evaluation parameters of four-point cooperative detection are analyzed and summarized and then based on the definition of volumetric tensor, the five-point formation is divided into five tetrahedrons and one main tetrahedron plus a fifth point to evaluate the detection efficiency. Finally, orbit data of five-spacecraft in one orbit period is used to simulate and analyze the two methods, and result shows that the method works well in evaluating five-point formation.

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  • Research on Large Thrust Liquid Rocket Engine
  • TAN Yong hua
  • 2013, 34 (10): 1303-1308. doi: 10.3873/j.issn.1000-1328.2013.10.002
  • Abstract ( 1635 ) PDF (1306KB)( 2538 )

    Large thrust rocket engine is the basic of aerospace development and the present of high tech level and comprehensive national strength. The development condition and trend of launch vehicle main power system is analyzed, and the large thrust LOX/Kerosene rocket engine and LOX/LH2 rocket engine are the development trend and the best combination in the future is put forward. In this paper, the general scheme and main parameters of large thrust LOX/Kerosene rocket engine and LOX/LH2 rocket engine for heavy launch vehicle are researched, and the key technology and resolvent is put forward. The two kinds of large thrust engines will offer power for space using, momentous space activities of manned lunar and deep space exploration.

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  • Mechanical Analysis and Bionic Structure Design of Astronautic Payloads Based on Natural Honeycomb
  • DONG Yong jin, ZHU Guang wu
  • 2016, 37 (3): 262-267. doi: 10.3873/j.issn.1000-1328.2016.03.003
  • Abstract ( 268 ) PDF (1926KB)( 2215 )

    The honeycomb sandwich structure which is widely used and researched in the field of navigation is different from the natural honeycomb in terms of structure. Research focused on the mechanical performance of natural honeycomb is rarely found. In this paper the 3-D models of the two types are established and the finite elements analysis is implemented to find whether the natural honeycomb is better than the common honeycomb sandwich in some aspects. The deformation and stress of the two types under axial and radial applied forces are found out and then the bionics intelligence of the natural honeycomb is brought to light. The mechanical performance unique to the natural honeycomb is applied to the structure design of some astronomic payloads, and good effects are got.

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