太阳帆航天器动力学与控制研究

发布时间：2018-06-07 09:37

本文选题：太阳帆 + 非开普勒轨道　；参考：《清华大学》2009年博士论文

【摘要】： 深空探测贯穿人类发展史,在科学、技术、政治和文化方面都有重要意义。随着深空探测任务距地球越来越远,燃料成为限制深空探测发展的一个重要因素。于是,人们提出了多种新型的推进方式,其中太阳帆可以提供连续小推力且比冲无限大,被认为是最实际的方法之一。NASA和ESA有多项相关飞行任务正在研制之中。太阳帆航天器的动力学与控制问题是理论研究的重点,对飞行任务的实现具有重要意义。太阳帆航天器不同于传统航天器,轨道和姿态是强耦合的。本文给出了耦合系统在周期轨道上稳定的条件;在轨道不影响姿态的情况下,推导了耦合系统的稳定性与轨道稳定性、姿态稳定性的关系。在只考虑轨道动力学的情况下,分析了太阳帆的被动控制。被动控制要求太阳帆的法线方向与太阳光之间的夹角保持不变,此时太阳帆的轨道总是稳定的且其轨道参数由太阳帆的初始角动量唯一确定。根据被动分析结果和耦合系统稳定的条件,设计了能在日心悬浮轨道和人工拉格朗日点被动稳定飞行的太阳帆结构。太阳帆技术在未来很长时间内无法达到多个任务提出的太阳帆尺寸要求。本文提出了太阳帆航天器编队飞行的概念,研究了几种简单姿态控制律下,各种悬浮轨道附近相对运动的稳定性。定义了一套描述椭圆相对轨道的相对轨道根数,分析了简单控制律下稳定相对轨道的特征,结果表明相对轨道的形状和空间指向都受到限制。为了得到更丰富的相对轨道,同时考虑到相对速度测量困难,研究了仅利用位置反馈进行相对轨道设计的方法。并利用数值算例验证了该设计方法的有效性。拉格朗日点附近编队研究中很重要的一个领域为编队控制。研究结果表明:利用脉冲控制很难实现高精度编队,太阳帆能提供微牛以下的连续小推力可以满足小尺度高精度编队需求。由于太阳光压力的方向受到限制,并非所有编队控制都能利用太阳帆。本文给出了太阳帆控制能力范围内的直线编队和圆形编队,利用数值算例验证了太阳帆实现编队控制的可行性。在小行星牵引任务中,引力拖车方法的优点是不依赖小行星特性、可靠性高,缺点是偏移能力有限。本文将太阳帆控制在小行星附近的悬浮轨道,实现对小行星轨道的偏移;进一步利用引力拖车编队提高偏移能力,研究了悬浮轨道上引力拖车编队的控制策略。最后,比较了普通引力拖车和太阳帆引力拖车的偏移能力。
[Abstract]:Deep space exploration runs through the history of human development and has important scientific, technical, political and cultural implications. As the deep space exploration mission is farther away from Earth, fuel becomes an important factor restricting the development of deep space exploration. Therefore, a variety of new propulsion methods have been proposed, in which the solar sail can provide continuous small thrust and infinite specific impulse, which is considered as one of the most practical methods. NASA and ESA have many related missions under development. The dynamics and control of solar sail spacecraft is the focus of theoretical research, which is of great significance to the realization of mission. The solar sail spacecraft is different from the traditional spacecraft, and its orbit and attitude are strongly coupled. In this paper, the condition of the stability of the coupled system in the periodic orbit is given, and the relation between the stability of the coupled system and the stability of the orbit and attitude is deduced when the orbit does not affect the attitude. The passive control of solar sail is analyzed under the condition of only considering orbital dynamics. Passive control requires that the angle between the normal direction of the solar sail and the solar light remain constant, and that the orbit of the solar sail is always stable and its orbit parameters are determined only by the initial angular momentum of the solar sail. According to the results of passive analysis and the condition of the stability of the coupled system, the solar sail structure which can fly passively and steadily at the heliocentric suspension orbit and the artificial Lagrange point is designed. Solar sail technology will not meet the requirements of solar sail size for many missions in a long time in the future. In this paper, the concept of formation flying of solar sail spacecraft is proposed, and the stability of relative motion near various levitation orbits under several simple attitude control laws is studied. In this paper, a set of relative orbital root numbers describing relative elliptic orbits is defined, and the characteristics of stable relative orbits under simple control law are analyzed. The results show that the shape and spatial direction of relative orbits are limited. In order to obtain more abundant relative orbits and take into account the difficulty of relative velocity measurement, a method of relative orbit design using position feedback is studied. The effectiveness of the design method is verified by numerical examples. Formation control is an important field in the formation study near Lagrange point. The results show that it is difficult to achieve high precision formation by using pulse control, and the solar sail can provide continuous and small thrust below microcattle to meet the demand of small scale high precision formation. Not all formation controls can use solar sails because the direction of solar pressure is limited. In this paper, the linear formation and circular formation within the range of solar sail control capability are given, and the feasibility of solar sail formation control is verified by numerical examples. In asteroid towing mission, the advantage of gravitational trailer method is that it is independent of asteroid characteristics, high reliability and limited migration ability. In this paper, the solar sail is controlled in the suspension orbit near the asteroid to realize the migration of the asteroid orbit, and the control strategy of the gravitational trailer formation on the suspension orbit is studied by using the gravitational trailer formation to improve the migration ability. Finally, the offsetting ability of the conventional gravitational trailer and the solar sail gravitational trailer is compared.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2009
【分类号】：V411.4

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