星际软着陆机动能力评估方法研究

Maneuver capability evaluation in planetary soft landing

针对软着陆过程中自主选取安全着陆点的需要,研究了探测器机动能力的评估方法.首先根据软着陆制导律,建立加速度模型积分结果与剩余燃料可生成速度增量之间的数学关系,推导出探测器机动能力的数值计算方法;其次,将软着陆过程中抵消重力作用与位置机动看作两个独立的过程,并假设位置机动过程为理想两脉冲机动,推导出解析的软着陆机动能力表达式;最后,通过数值仿真表明两种分析方法能够得到相近的结果,解析的机动能力分析方法可以实时的对探测器可能着陆区域进行预测,能够为探测器自主的选定着陆点提供重要依据.

Analysis methods for evaluating the maneuver capability in planetary terminal soft landing are researched based on the request of autonomous landing point redesignation.Firstly,to find out the relationship between acceleration model integral result and available velocity increment,a numerical method of maneuver capability analysis is deduced.Secondly,based on the assumption that counteracting the gravity effect and the position maneuver are two independent processes and the position maneuver is an ideal two-impulse maneuver,an analytic expression of maneuver capability analysis is proposed.Simulation result shows that the two methods can get similar results,and the analytic method can predict the potential landing point in real time,which plays an essential role in landing point redesignation.