Attitude Control of a Satellite Simulator Using Reaction Wheels and a PID Controller

摘要

Attitude requirements of a satellite are determined by its mission: telecommunications, optical imagery, and meteorology to name a few. A satellite's ability to orient its mission critical hardware (solar arrays, attitude sensors, etc.), as well as its mission specific payload, is incumbent upon the performance of the satellite's attitude control system (ACS). For a highly accurate ACS and for moderately fast maneuverability, reaction wheels are preferred because they allow continuous and smooth control while inducing the smallest possible disturbance torques. The objective of this research is to design, build, test, and evaluate the performance of a reaction wheel ACS on- board the Air Force Institute of Technology's (AFIT) second generation satellite simulator, SimSat II. The reaction wheel ACS is evaluated against performance measures set forth by AFIT faculty; specifically, the ability to perform rest-to-rest maneuvers and withstand worst case disturbance torques. In all, the reaction wheel ACS proves it is capable of performing rest-to-rest maneuvers and withstanding disturbance torques. However, results conclude that theoretical predicted performance is unattainable. The performance of the reaction wheel ACS hinges upon its ability to command the reaction wheels at fixed interval timing. The inability of the test bed to execute fixed interval timing caused performance degradation.