平动点卫星与地球导航卫星联合自主定轨技术研究

发布时间：2018-10-25 08:30

【摘要】：平动点卫星特殊的动力学性质决定了它在深空探测中的重要意义,其中深空导航通信是平动点卫星的重点应用方向之一。平动点拟周期轨道的时空唯一性是仅利用星间测距实现自主定轨的理论依据。本文在五个平动点各选一颗拟周期轨道卫星组成了平动点导航卫星星座,推导了平动点卫星星座在圆型限制性三体问题模型和椭圆型限制性三体问题模型下的状态转移矩阵和观测矩阵,并以此为基础建立了基于星间距离观测的卫星星座自主定轨模型。在自主定轨数值仿真实验中采用了扩展卡尔曼滤波和无迹卡尔曼滤波算法,并比较了两种算法在三体问题模型这一强非线性系统中的表现。仿真实验结果表明平动点卫星仅利用星间测距自主定轨能保持定轨误差180天内不发散,即使在加入初值误差的情况下,x轴和y轴的误差依然能够收敛。平动点卫星能够仅利用星间测距信息进行自主定轨是因为平动点卫星轨道包含了星座的绝对方位信息,因此理论上地球导航卫星可以利用对平动点卫星的距离观测量来解决其无法绝对定位的问题。本文以地月系统为研究对象,在系统质心旋转坐标系中描述了平动点卫星的运动以及平动点卫星和地球导航卫星之间的距离观测模型,而地球轨道卫星的运动更适合在地球赤道惯性坐标系中表述,因此给出了地心赤道惯性坐标系和质心旋转坐标系的转换方法,推导了平动点卫星和地球导航卫星之间的距离观测量对地球导航卫星轨道根数的偏导数,最后按照集中式数据处理方式拟定了平动点卫星和地球导航卫星联合定轨方案。数值仿真实验中采用12颗GPS卫星和5颗平动点卫星,仿真的首要目的是验证联合定轨方案的可行性。在联合定轨方案可行的前提上设计了对照实验来比较星间测向方案和联合定轨方案的优劣。平动点卫星自主定轨研究结果表明,在平动点布置导航星座可以实现仅利用星间测距进行自主定轨,这对提高深空探测的安全性和自主性具有重要的意义。平动点卫星与地球导航卫星联合自主定轨的仿真结果证实了平动点卫星能够抑制地球导航卫星由于星座整体旋转引起的误差发散,联合定轨方案可以作为地球导航卫星自主定轨的备选方案,该方案对保证地球导航卫星的导航精度和系统稳定性有一定的意义。
[Abstract]:The special dynamic property of the translational point satellite determines its significance in the deep space exploration, in which the deep space navigation communication is one of the important application directions of the translational point satellite. The spatio-temporal uniqueness of quasi-periodic orbits at translational points is the theoretical basis for autonomous orbit determination only by using intersatellite ranging. In this paper, the constellation of the translational point navigation satellite is composed of one quasi-periodic orbit satellite at each of the five translational points. The state transfer matrix and observation matrix of the translational point satellite constellation under the circular restricted three body problem model and the elliptic restricted three body problem model are derived. An autonomous orbit determination model of satellite constellation based on intersatellite distance observation is established. The extended Kalman filter and the unscented Kalman filter algorithm are used in the autonomous orbit determination numerical simulation experiment, and the performance of the two algorithms in the three-body problem model is compared. The simulation results show that the orbit determination error of the translational point satellite can be maintained within 180 days only by using the autonomous orbit determination of intersatellite ranging. Even if the initial error is added, the errors of x axis and y axis can still converge. The orbit of the translational point satellite can be determined independently only by using the ranging information between satellites because the orbit of the translational point satellite contains the absolute azimuth information of the constellation. Therefore, in theory, the Earth navigation satellite can use the distance observation of the translational point satellite to solve the problem of its absolute positioning. In this paper, the motion of the translational point satellite and the distance observation model between the translational point satellite and the Earth navigation satellite are described in the rotation coordinate system of the centroid of the earth moon system. The motion of the Earth orbit satellite is more suitable to be expressed in the Earth's equatorial inertial coordinate system, so the transformation method of the geocentric equatorial inertial coordinate system and the mass center rotation coordinate system is given. The partial derivative of the distance observation between the translational point satellite and the Earth navigation satellite to the orbital root number of the Earth navigation satellite is derived. Finally, the joint orbit determination scheme of the translational point satellite and the Earth navigation satellite is formulated according to the centralized data processing method. In the numerical simulation experiment, 12 GPS satellites and 5 translational point satellites are used. The primary purpose of the simulation is to verify the feasibility of the combined orbit determination scheme. Based on the feasibility of the joint orbit determination scheme, a comparative experiment was designed to compare the advantages and disadvantages of the intersatellite direction finding scheme and the joint orbit determination scheme. The results of the autonomous orbit determination of the stratospheric satellite show that the navigation constellation can only be determined by intersatellite ranging, which is of great significance to improve the safety and autonomy of deep space exploration. The simulation results of the simultaneous autonomous orbit determination of the translational point satellite and the Earth navigation satellite confirm that the translational point satellite can restrain the divergence of errors caused by the global rotation of the constellation of the earth navigation satellite. The joint orbit determination scheme can be used as an alternative for autonomous orbit determination of the Earth navigation satellite. This scheme has a certain significance to ensure the navigation accuracy and system stability of the Earth navigation satellite.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V448.2;V412.41

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