基于重要性测度的一箭多星分离安全性分析

Study on safety of multi-satellite launch mission based on importance measure

对于一箭多星发射任务,各颗卫星分离速度及分离角度可能存在一定误差,使得分离后星间距离存在不确定性,从而影响分离安全性.为提高一箭多星分离安全性,利用重要性测度分析方法对卫星入轨分离后的星间距离开展研究.提出了基于移动最小二乘的重要性测度指标求解新方法,数值算例表明新计算方法相比传统的Monte Carlo方法和Saltelli方法效率更高.针对分离后星间距离过于接近的情况,重要性测度分析方法能够有效识别出对星间距离影响较大的变量,对这些变量的分布参数进行优化调整后,星间最小距离明显增大且不确定性降低,从而保证了一箭多星的分离安全性.

For multi-satellite launch mission, the velocity and direction of each satellite at separation may deviate from nominal value, which will introduce uncertainty to the distances between satellites after separation, and influence the safety as a result. In order to improve the satellite rocket separation safety of multi-satellite launch mission, importance measure analysis technology is employed to analyze the distance between satellites after separation. A new method is proposed to calculate the importance measures, numerical example shows that the efficiency of the proposed method is higher than the traditional Monte Carlo method and Saltelli's method. For the situation that distance between satellites is too close after separation, importance measure analysis technology can be used to identify the input variables those have greater influence on the distances between satellites, then the distribution parameters of those input variables can be optimized, which can increase the minimum distance between satellites, and decrease its uncertainty as well. As a result, the safety during separation can be insured.