空间电动力绳系系统热-电-柔耦合动力学建模与控制研究

Space electrodynamic tether system is a new type of space technology with advantages of low mass, fuel-less and ease of operation. It can be used to complete power generation of conductive tether, space debris deorbit, orbit propulsion and orbit maintenance etc. The system carries a long and conductive flexible tether, which belongs to a multi-physics coupling system. It has a high degree of non-linearity and complexity, making it unique in dynamic theory, deployment control and long-term orbital station-keeping/transfer control. This project is aimed at key scientific issues such as "high-precision thermal-electric-flexible coupling dynamic model construction of space electrodynamic tether system", "on-orbit deployment stability control and long-term orbital station-keeping/transfer optimal control of space electrodynamic tether under complicated model". Specially, in this project, considering the attitude movement of the end spacecrafts, a thermal-electric-flexible coupling dynamic modeling method of space electrodynamic tether system is proposed and the influence of the end spacecraft motion on the system is analyzed; considering the control constraints and robustness, a tension and current deployment underactuated control law based on backstepping method of 3D electrodynamic tether system is developed; considering spatial perturbation and multi-constraint conditions, a closed-loop optimal long-term orbital station-keeping/transfer current control based on nonlinear prediction method is proposed. The research will provide theoretical support for the development of space electrodynamic tether system in on-orbit tests and missions.

空间电动力绳系系统是一种具有质量轻、低燃耗、易操作等优势的新型航天技术，可利用其完成导电系绳发电、空间碎片离轨、轨道推进及轨道高度维持等。此系统携带较长且可导电的柔性系绳，属于多物理场耦合系统，具有高度非线性和复杂性，使得其在动力学理论、展开控制与长时轨道保持/转移控制方面存在独特的问题。本项目针对“空间电动力绳系系统热-电-柔耦合动力学模型构建”、“复杂模型下的空间电动力绳系系统在轨展开稳定控制和长时轨道保持/转移最优控制”等关键科学问题，提出一种考虑系绳末端航天器姿态运动的空间电动力绳系系统热-电-柔耦合动力学建模方法，并分析末端航天器运动对系统的影响；考虑控制约束和鲁棒性要求，提出一种基于反步法的欠驱动三维电动力绳系展开拉力与电流控制方法；考虑空间摄动与多约束条件，提出一种基于非线性预测方法的闭环最优长时轨道保持/转移电流控制方法。为空间电动力绳系在轨试验和任务的发展提供理论支撑。

空间电动力绳系系统是一种具有质量轻、低燃耗、易操作等优势的新型航天技术，可利用其完成导电系绳发电、空间碎片离轨、轨道推进及轨道高度维持等。此系统携带较长且可导电的柔性系绳，属于多物理场耦合系统，具有高度非线性和复杂性，使得其在动力学理论、展开控制与长时轨道保持/转移控制方面存在独特的问题。本项目针对“空间电动力绳系系统热-电-柔耦合动力学模型构建”、“复杂模型下的空间电动力绳系系统在轨展开稳定控制和长时轨道保持/转移最优控制”等关键科学问题，提出了一种考虑系绳末端航天器姿态运动的空间电动力绳系系统热-电-柔耦合动力学建模方法，建立了考虑摄动的高精度空间电动力绳系系统模型；在此基础上，考虑控制约束和鲁棒性要求，提出了一种基于反步法的欠驱动三维电动力绳系展开拉力与电流控制方法，实现了欠驱动电动力绳系统展开稳定控制；最后，考虑空间摄动与多约束条件，提出一种基于非线性预测方法的闭环最优长时轨道保持/转移电流控制方法，仅通过调节有限的电流，不依赖其他推进器，实现了电动力绳系统的长时离轨控制，为空间电动力绳系在轨试验和任务的发展提供理论支撑。