雙翼雙軸衛星的建模與姿態控制

Abstract

近代衛星因任務多樣化需要高能量消耗而採用高縱橫比的太陽能板，導致柔性振動模態影響姿態控制。本論文主要考慮對稱雙翼的衛星構型，且翼片有兩個正交的旋轉自由度會改變系統旋轉慣量與柔固耦合效應。研究方法包括三種建模架構：多體建模(Multibody modeling)、線性分式變換(Linear fractional transformation, LFT)以及質量彈簧阻尼系統(Mass-damper-spring system, MDK)，這些模型基於有限元分析構建，能模擬具有柔固耦合特性的衛星響應。三種建模架構在與Simscape建立的線性化模型交叉驗證後，均證實其可靠性。控制器設計方面以質量彈簧阻尼系統為基礎，透過H∞控制器設計的線性矩陣不等式(Linear matrix inequality)方法，設計靜態回授和線性參數變化的前饋控制器，實現系統穩定和動態性能提升。將控制器配置於Simscape的非線性動態模型中模擬，得到了不錯的追蹤性能表現。本論文整合各種建模方法，為衛星參數選擇和發射前驗證提供支持，並建置一組應對雙軸自由度旋轉慣量變化的姿態控制器。

Modern satellites, due to their diversified mission requirements, require high energy consumption and thus employ high aspect ratio solar panels. This leads to flexible vibration modes affecting attitude control. This thesis primarily considers a satellite configuration with symmetric dual appendages, where the appendages have two orthogonal rotational degrees of freedom, altering the system's rotational inertia and flexible-rigid coupling effects. The research methodology includes three modeling frameworks: multibody modeling, linear fractional transformation (LFT), and mass-damper-spring system (MDK). These models, based on finite element analysis, can simulate satellite responses with flexible-rigid coupling characteristics. The reliability of these three modeling frameworks is validated through cross-verification with a linearized model in Simscape. For controller design, a MDK system is utilized as the foundation. Using the linear matrix inequality (LMI) method for H∞ controller design, both static feedback and linear-parameter-varying (LPV) feedforward controllers are developed to achieve system stability and enhanced dynamic performance. The controllers are implemented in a nonlinear dynamic model in Simscape, yielding satisfactory tracking performance. This thesis integrates various modeling methods to support satellite parameter selection and pre-launch verification and establishes an attitude controller capable of handling the inertia changes due to dual-axis rotational degrees of freedom.