Dynamics and Control of Tethered Spacecraft Systems

系留航天器系统的动力学与控制

基本信息

批准号：
RGPIN-2018-05991
负责人：
Zhu, ZhengHong
金额：
$ 4.66万
依托单位：
York University
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2019
资助国家：
加拿大
起止时间：
2019-01-01 至 2020-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691227
关键词：
Dynamics Control Tethered Spacecraft Systems

项目摘要

Tethered Spacecraft Systems (TSS) are novel devices to extend the capability of spacecraft to conduct scientific and other tasks. Among them, the propellantless propulsion by electrodynamic tethers in Earth orbits or electrostatic tethers beyond Earth orbits is an appealing alternative to existing rocket propulsion. However, TSS are difficult to operate due to their extreme long length and variable configurations. As such, a thorough understanding of dynamics and control of TSS is a preoccupation for any successful TSS mission.******High-fidelity modeling of TSS inevitably leads to a set of nonlinear, distributed and coupled partial differential equations. The control of such systems subject to stochastic perturbative effects requires feedback of states. However, interior states along tether length are not measurable as sensors are only available at spacecraft connected at tether ends. This leads to a challenging feedback control for distributed systems with only boundary observation. Furthermore, the implementation and validation of control laws for TSS before launch are equally challenging. Novel ground test facility and theory are required to scale down the real TSS into testbeds with limited dimensions.******The aim of this discovery program is to systematically study fundamentals of dynamics and control of TSS in and beyond Earth orbits. Builds on the success of previous Discovery Grant, new computational control for flexible TSS will be developed by considering multiphysics, coupled rigid-flexible dynamics, orbital perturbations, and boundary feedback control with limited observation at boundary. First, a new nodal position finite element Kalman filter will be developed to give spatial and temporal estimates of interior states (motion and electric voltage) along tether length based on feedback at tether's ends. Second, a novel computational control without explicit structures for TSS will be developed by combining a dual adaptive model predictive control with the nodal position finite element Kalman filter. Third, the derived computational control will be used for tether deployment/retrieval, effective and efficient space debris deorbit by electrodynamic tether, and interplanetary travel by electrical solar wind sail. Fourth, ground tests will be conducted to validate the proposed computational control. Finally, key components of TSS will be tested in microgravity by parabolic flights and prototype of electrodynamic tether deorbit device will be demonstrated in space.******The discovery program will train HQP in multi-physical modeling, coupled rigid-flexible dynamics, astrodynamics, advanced control theory, space environment, software, hardware, and experimental validation. HQP will also be trained in professional development through discussion with collaborators and team members, participation in real TSS space mission, and collaboration with space industry.**

系留航天器系统（TSS）是一种新颖的设备，可扩展航天器执行科学和其他任务的能力。其中，地球轨道上的电动系绳或地球轨道外的静电系绳的无推进剂推进是现有火箭推进的一种有吸引力的替代方案。然而，TSS由于其极长的长度和可变的配置而难以操作。因此，对 TSS 动力学和控制的透彻理解是任何成功的 TSS 任务的当务之急。********TSS 的高保真建模不可避免地会产生一组非线性、分布和耦合的偏微分方程。对此类受随机微扰效应影响的系统的控制需要状态反馈。然而，沿着系绳长度的内部状态是不可测量的，因为传感器仅适用于连接在系绳末端的航天器。这给仅具有边界观察的分布式系统带来了具有挑战性的反馈控制。此外，发射前 TSS 控制法的实施和验证同样具有挑战性。需要新颖的地面测试设施和理论来将真实的 TSS 缩小为尺寸有限的测试台。******该发现计划的目的是系统地研究地球轨道内外 TSS 的动力学和控制基础知识。在先前发现资助计划的成功基础上，将通过考虑多物理场、刚柔耦合动力学、轨道扰动和有限边界观测的边界反馈控制来开发灵活 TSS 的新计算控制。首先，将开发一种新的节点位置有限元卡尔曼滤波器，以根据系绳末端的反馈给出沿系绳长度的内部状态（运动和电压）的空间和时间估计。其次，通过将双自适应模型预测控制与节点位置有限元卡尔曼滤波器相结合，将开发一种没有显式 TSS 结构的新型计算控制。第三，衍生的计算控制将用于系绳部署/回收、通过电动系绳有效且高效的空间碎片脱轨以及通过电动太阳风帆进行星际旅行。第四，将进行地面测试以验证所提出的计算控制。最后，TSS 的关键部件将通过抛物线飞行在微重力下进行测试，电动系绳脱轨装置原型将在太空中进行演示。******该发现计划将在多物理建模、刚柔耦合动力学方面对 HQP 进行培训、天体动力学、先进控制理论、空间环境、软件、硬件和实验验证。 HQP 还将通过与合作者和团队成员的讨论、参与真正的 TSS 太空任务以及与航天工业的合作来接受专业发展培训。**