Solar Sailing: Attitude, Orbit, and Shape Control

太阳航行：姿态、轨道和形状控制

• 批准号: RGPIN-2020-04037
• 负责人: Damaren, Christopher
• 金额: $ 2.84万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716353
• 关键词: Solar; Sailing; Attitude; Orbit; Shape

Spacecraft exhibit three distinct types of motion. The evolution of their position in space is the subject of orbital dynamics. The evolution of their orientation with respect to some reference, such as the Earth, is described by attitude dynamics. Larger spacecraft can be quite flexible and one is concerned with their structural dynamics which describes vibrational and wrinkling types of behaviour. Controlling these three types of motion typically requires feedback control systems which use sensors to monitor the spacecraft motion and then correct errors using appropriate actuators which produce forces and torques. Forces are required to control orbits whereas torques are needed to control orientation (also called attitude). In some problems, the spacecraft's attitude can have a large effect on its orbit. An interesting example is a solar sail, which is a large, flimsy gossamer structure which acts a mirror to reflect the solar radiation acting upon it. This produces a reaction force on the sail. Controlling solar sails is a challenging application because the orbital dynamics, attitude dynamics, and structural dynamics are highly coupled. The orbital path and the orientation of the sail are coupled because the forces stemming from radiation pressure act in a direction that depends on the sail attitude. This is analogous to the motion of a sailboat moving on the surface of a lake in wind. A useful destination for a solar sail is a point between the Sun and the Earth where the solar sail can be used to detect solar storms and communicate a warning to the Earth before the storm arrives. Another useful point to place a solar sail is in a "pole-sitter" position whereby the sail does not orbit the Earth but rather sits above the North Pole and moves with the Earth as it moves around the Sun. In order to use these special orbits, one needs to develop steering strategies to achieve them. We would like to determine attitude motions to reach these places in the shortest time possible. Given the solution of the previous problem, we would like to determine control approaches to follow a prescribed attitude motion. Two actuation approaches will be studied: the use of tip vanes (little miniature solar sails gimballed to the corners of the main sail) and the use of balance masses. The key problem that needs to be solved initially is the determination of the actuator motion required to provide the control torques required by the control system. Having handled the coupled attitude-orbit control problem, the next problem in the hierarchy to be studied brings shape control into play. There are two subproblems to be considered: vibration suppression and wrinkle prevention. Both are complicated by the lack of distributed actuation and sensing and the fact that the actuation is physically noncollocated with the typical sensing which one assumes would include the attitude and angular rate information measured at the centre of the sail.

航天器表现出三种不同类型的运动。 它们在空间中位置的演变是轨道动力学的主题。 它们相对于某些参照物（例如地球）的方向演变是通过姿态动力学来描述的。 较大的航天器可以非常灵活，人们关心的是它们的结构动力学，它描述了振动和起皱类型的行为。 控制这三种类型的运动通常需要反馈控制系统，该系统使用传感器来监测航天器的运动，然后使用产生力和扭矩的适当执行器来纠正错误。 需要力来控制轨道，而需要扭矩来控制方向（也称为姿态）。 在某些问题中，航天器的姿态可能对其轨道产生很大影响。 一个有趣的例子是太阳帆，它是一个巨大而脆弱的薄纱结构，可以充当镜子来反射作用在其上的太阳辐射。这会在帆上产生反作用力。控制太阳帆是一项具有挑战性的应用，因为轨道动力学、姿态动力学和结构动力学是高度耦合的。 轨道路径和帆的方向是耦合的，因为辐射压力产生的力的作用方向取决于帆的姿态。 这类似于帆船在风中在湖面上移动的运动。 太阳帆的一个有用目的地是太阳和地球之间的一个点，在那里太阳帆可用于检测太阳风暴并在风暴到来之前向地球发出警告。放置太阳帆的另一个有用点是处于“极坐”位置，即太阳帆不绕地球运行，而是位于北极上方，并在地球绕太阳运动时与地球一起移动。为了使用这些特殊轨道，需要制定转向策略来实现它们。 我们希望确定在尽可能短的时间内到达这些地方的姿态动作。 考虑到上一个问题的解决方案，我们希望确定控制方法来遵循规定的姿态运动。将研究两种驱动方法：使用尖端叶片（用万向节固定在主帆角上的微型太阳帆）和使用平衡质量。 最初需要解决的关键问题是确定提供控制系统所需的控制扭矩所需的执行器运动。 处理完耦合的姿态轨道控制问题后，要研究的下一个问题将发挥形状控制的作用。 有两个子问题需要考虑：振动抑制和防皱。 由于缺乏分布式驱动和传感，以及驱动在物理上与典型传感不并置的事实，两者都变得复杂，人们假设典型传感包括在帆中心测量的姿态和角速率信息。