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行星际天文导航方法及其精度影响因素分析

Interplanetary Celestial Navigation Method and Analysis of Its Accuracy Influential Factors

【作者】 李建国

【导师】 杨亚非;

【作者基本信息】 哈尔滨工业大学 , 控制科学与工程, 2009, 硕士

【摘要】 21世纪世界各国都加快了太空探索的步伐,飞行任务的长时间远距离和深空环境的复杂性决定了天文导航方法成为最适合行星际飞行的自主导航方法。针对具体的飞行任务研究合理的行星际天文导航方法并对其进行优化设计,无论在理论上还是工程上均具有重要意义。本论文研究了适合星际巡航飞行的天文导航方法,并对其精度影响因素进行了针对性研究。主要内容包括:建立了基于多体问题的探测器的轨道动力学模型和无陀螺姿态运动模型。结合观测模型,对现有的近地空间和深空自主天文导航方法进行了总结和比较,研究了适合星际巡航飞行的自主天文导航方法。在所提出的行星际自主天文导航方法基础上,着重研究了状态方程、量测方程和滤波算法的选取对系统导航精度的影响。首先,建立了不同轨道描述参数和姿态描述参数下的系统模型,分析了不同状态描述形式对系统计算效率和导航精度的影响。其次,考虑到探测器所处的深空环境和所用的观测手段,研究了最优导航天体的筛选准则,并结合导航系统的可观测性和可观测度,进一步分析了星敏感器的测量精度、导航恒星的数目和量测模型对系统导航精度的影响。最后,研究了常用的非线性滤波算法,并针对自主导航系统的非线性、非高斯及初始导航偏差较大的问题,仿真分析了UKF和UPF对系统导航精度的影响。为导航系统参数的选取提供了良好的理论基础。

【Abstract】 Many countries around the world have accelerated the pace of space exploration in the new century. The long-time and far-distance flight and the complicated environment determine the celestial navigation method as the most appropriate autonomous navigation method for deep space missions. The research of rational interplanetary celestial navigation method and its optimum design according the specific mission have important theoretical significance and applied value. This paper studies the autonomous celestial navigation method suitable for interplanetary cruise flight and analyses its accuracy influential factors. The main contents of this paper are as follows.Orbit dynamical models based on multi-body problem and gyroless attitude motion models of the probe are established. This paper summarizes and compares the existing near-earth space and deep space autonomous navigation methods based on the measurement models. An autonomous navigation method suitable for interplanetary cruise flight is presented.Based on the above research results, this paper emphatically studies the effect of the selection of the state equation, measurement equation and the filter algorithm on the navigation accuracy. First, the system models of different orbit representation parameters and attitude representation parameters are established, and then the effect of different state representations on the computation efficiency and the navigation accuracy. Second, the optimal selection criteria of the navigation celestial bodies are proposed considering the deep space environment of the probe and the observational methods. Then the effect of the star sensor precision, the numbers of the navigation stars and the measurement models on the navigation accuracy is analysed by using the observability theory and the observability index theory. Finally, the popular nonlinear filtering algorithm is researched in this paper. In view of the nonlinear non-Gasussian and the problem of large deviation of initial estimation of the navigation system, the effect of the UKF and UPF on system navigation accuracy is presented by the numerical simulation. The results offer nice theoretical basis to the choice of navigation system parameters.

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