火星着陆任务落点误差快速分析方法

A new landing site uncertainty analysis method for mars entry mission

摘要:

在火星着陆任务设计中,为高效地评估进入点导航误差等动力学方程中的不确定因素对着陆精度的影响,引入Galerkin投影法则,提出一种火星着陆落点不确定度快速预报与分析方法．该方法采用Wiener-Askey正交多项式逼近着陆器状态,将落点误差的预报问题转换为1个确定性微分方程的求解问题．最后以我国未来实施火星着陆探测为背景,分别用本文算法和蒙特卡洛方法进行数值仿真分析,结果表明,本文算法能够对落点偏差进行快速分析,准确预测其均值和方差,且计算效率明显提高．

Abstract:

To evaluate how the uncertain factors in the entry dynamics such as the navigation errors at the entry point affect the landing precision effectively, by introducing the Galerkin projection, a rapid landing error prediction method for Mars entry is proposed. In this method, the Polynomial Chaos are used to approximate the vehicle's states, and the problem is converted to a deterministic dynamical systems. Applying the method to a representative entry scenario of our country's future Mars entry mission, simulation results indicate that, compared with Monte Carlo method, the proposed method is able to predict the mean and covariance with little error and more computational efficiency.