Attitude Control Method for Liquid-Filled Flexible Spacecraft Based on Wave-Based Control

Abstract

A spacecraft often consists of a main rigid body, flexible appendages, and liquid loads such as fuel. Precise positioning and fast stabilization are crucial, but the complex interactions among rigid, flexible, and liquid components lead to residual vibrations, which can deteriorate performance, causing undesired effects like jitter, pogo oscillation, or resonance. Specifically, the coupling between fuel slosh and solar panel vibrations challenges control accuracy. This study compares the performance of wave-based and proportional-derivative controllers through numerical simulations of a liquid-filled spacecraft with a flexible appendage during an attitude maneuver in a microgravity environment. Notably, the impact that wave-based control has over the spacecraft attitude maneuvering states is greater than the proportional derivative controller, but requires a decreased control input cost. Comparison with an experiment using linear-quadratic-Gaussian control reveals that wave-based control does not instigate high-frequency vibration even when the correction is abrupt. These findings are valuable for spacecraft modeling, dynamic analysis, and control system design.