探测器环绕火星自主导航方法研究

发布时间：2018-06-05 01:36

本文选题：火星探测 + 可观测性　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：自主导航以其相较于其他导航方式的实时性、可靠性等特性发展为深空探测的重要技术之一,而且其在国外的深空探测系列活动中已经成功验证并逐步开始应用在实际任务中。在我国的深空探测规划中,发展自主导航技术已成为重要研究方向。本文以火星探测为背景,重点研究了深空探测器在火星环绕段的自主导航方法。本文首先建立了所需的时空系统,并给出不同坐标系之间的转换关系,同时计算了太阳和火星天然卫星在火星惯性系下的星历,然后综合考虑火星形状、大气阻力、太阳光压、太阳引力以及火星天然卫星等主要摄动因素的影响,在火星赤道惯性系下建立探测器的轨道动力学模型,并分析了摄动力对探测器轨道的影响。同时与STK仿真模型进行对比,给出了相比于参考模型的误差,验证了所建立动力学模型的精确性。为更真实地模拟探测器的测量数据,具体分析了影响探测器观测火星天然卫星以及火星路标的因素:火星遮挡条件、火星阴影条件以及太阳逆光条件,并给出了造成不可见条件的具体方程,并对不同任务轨道的可观测弧段进行了对比仿真,结果显示对于不同高度的任务轨道,虽然对卫星与路标可见性的主要影响因素各不相同,但最终都可归结为目标、火星以及太阳间的位置关系。在探测器环绕火星飞行段,首先针对导航系统是否可观测的问题,通过分析观测模型对状态量的偏导数方程之间的独立性来判别,并利用观测矩阵的条件数分析了可观测度。对以导航信标视线矢量为观测量的导航系统,利用最小二乘算法对多组测量数据进行批处理,然后利用牛顿迭代计算出探测器在环绕段的轨道要素,同时对利用火星表面上已知位置特征的路标的导航方法进行仿真分析。最后,通过对比仿真分析了轨道高度、采样周期、采样点个数、测量噪声以及导航信标的选取对轨道确定精度的影响,并以初定轨结果作为轨道初值进行轨道预报,分析误差传递情况。
[Abstract]:Compared with other navigation methods, autonomous navigation has developed into one of the most important deep space exploration technologies for its real-time and reliability characteristics. Moreover, autonomous navigation has been successfully verified and gradually applied in practical missions in a series of deep space exploration activities abroad. In the deep space exploration planning in China, the development of autonomous navigation technology has become an important research direction. In this paper, based on the background of Mars exploration, the autonomous navigation method of deep space rover in the orbit of Mars is studied. In this paper, the necessary space-time system is first established, and the transformation relations between different coordinate systems are given. The ephemeris of the sun and the Martian natural satellites under the inertial system of Mars are calculated at the same time, and then the shape of Mars, atmospheric resistance and solar pressure are considered synthetically. Under the influence of the main perturbation factors such as the solar gravity and the Martian natural satellite, the orbital dynamics model of the probe is established under the Martian equatorial inertial system, and the influence of the perturbation force on the orbit of the probe is analyzed. At the same time, compared with the STK simulation model, the error compared with the reference model is given, and the accuracy of the established dynamic model is verified. In order to simulate the measured data of the probe more realistically, the factors that affect the observation of the natural Mars satellite and the Mars signpost are analyzed in detail: the condition of the occlusion of Mars, the condition of the shadow of Mars and the condition of the inverse light of the sun. The specific equations of the invisible conditions are given, and the observable arc segments of different mission orbits are compared and simulated. The results show that for different mission orbits at different heights, Although the main factors affecting the visibility of satellites and landmarks are different, they are ultimately attributed to the location of the target, Mars and the sun. In the spacecraft flight around Mars, the observability of the navigation system is first analyzed by analyzing the independence of the partial derivative equations of the observation model to the state variables, and the observable measure is analyzed by using the condition number of the observation matrix. For navigation system with navigation beacon line of sight vector as observation, the least square algorithm is used to batch process multiple sets of measurement data, and then Newton iteration is used to calculate the orbital elements of the detector in the circumferential section. At the same time, the navigation method based on the known position features on Mars surface is simulated and analyzed. Finally, the influence of orbit height, sampling period, number of sampling points, measurement noise and the selection of navigation beacon on the orbit determination accuracy is analyzed by comparison and simulation, and the orbit prediction is carried out with the initial orbit determination result as the initial orbit value. Analyze the error transmission.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V448.2

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