嫦娥三号软着陆轨道设计与落点避障

摘要

This paper designs and calculates the control scheme of the soft landing process of Chang ’e-3. The dynamics equation is established based on the parabolic trajectory, with minimum fuel consumption as the goal, and the landing preparatory track position is determined. According to the tasks of different stages, different guidance methods are implemented, the optimal control strategies for the six stages of soft landing are given, and time consumption and lander quality are calculated at each stage. In the stage of obstacle avoidance, through the gray-level threshold analysis of digital elevation map, the ways of binarization processing, flat map conversion, obstacle circle delimitation are chosen to select the landing point. Finally, error analysis and sensitivity analysis about the model are made.%设计与计算嫦娥三号软着陆过程的控制方案。建立基于抛物线运行轨迹的动力学方程，以燃料消耗最少为目标，确定着陆准备轨道的位置；根据不同阶段的任务，实施不同的制导方式，给出软着陆6个阶段的最优控制策略，并算得各阶段的耗时与着陆器质量；在避障阶段，通过对数字高程图的灰度阈值分析，采用二值化处理、平坦图转换、障碍圆划定等方法选定着陆点；最后，对所建模型作出误差分析和敏感性分析。