中国空间科学技术

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一种航天器防护与遮挡的几何描述算法研究

裴扬,宋笔锋,李占科   

  1. 西北工业大学,西北工业大学,西北工业大学 西安710072 ,西安710072 ,西安710072
  • 发布日期:2004-10-25

On Geometric Description Algorithm of Spacecraft Shielding or Masking

Pei Yang Song Bifeng Li Zhanke(Northwestern Polytechnical University, Xi'an 710072)   

  • Online:2004-10-25
  • Supported by:
    国家自然科学基金 (19972 0 56、 10 3 72 0 82 );; 西北工业大学博士论文创新基金 (CX2 0 0 3 0 1)

被引次数

2

摘要： 文中提出了一种航天器部件在任意威胁攻击方向上的投影面积和重叠面积的计算方法及部件间遮挡关系的确定方法。采用“几何拼接法”或借助有限元软件来建立航天器及其部件模型。将航天器各个部件向投影坐标系进行投影获得部件投影边界图形。利用垂直扫描线对各个部件的投影多边形进行扫描并进行求交运算 ,形成多个分散的四边形 ,在每个四边形内产生射击线 ,累加求出航天器易损性评估中所需的部件投影面积、重叠面积及遮挡关系。算例对三个正方体形状的部件进行了几何描述 ,当扫描线步长取 2cm时 ,投影面积及重叠面积计算值与理论值的最大相对误差为 5 0 6% ;当扫描线步长取 0 5cm时 ,最大相对误差为 1 2 5 %。结果表明算法通用性强 ,易于实现

关键词: 几何描述算法, 有限元法, 易损性, 风险评估

Abstract: 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.