Session
Session III: Where We're Going Section 2
Abstract
This paper looks at attitude control considerations for a small flexible spacecraft with a gravity gradient boom constructed from elastic memory composites. Free-free boundary conditions are used in the development of the system’s equations of motion. Finite element model analysis generates the needed mode shape matrix and resonant frequencies. Modal coordinates are chosen over physical coordinates during the LQG/LTR controller design due to the greatly reduced number of states to control. Controller robustness and pole-zero cancellation techniques further reduce the order of the control transfer matrix. System performance characteristics are determined for the system in response to optimal maneuvering to nominal pointing following a momentum dumping procedure of the reaction wheels. The simulation identified the need to include the first resonant modes in the design model to ensure the system is robust in the presence of uncontrolled higher frequency modes and modeling errors.
Presentation Slides
LQG/LTR Control of Small Flexible Spacecraft with Elastic Memory Composite Appendages
This paper looks at attitude control considerations for a small flexible spacecraft with a gravity gradient boom constructed from elastic memory composites. Free-free boundary conditions are used in the development of the system’s equations of motion. Finite element model analysis generates the needed mode shape matrix and resonant frequencies. Modal coordinates are chosen over physical coordinates during the LQG/LTR controller design due to the greatly reduced number of states to control. Controller robustness and pole-zero cancellation techniques further reduce the order of the control transfer matrix. System performance characteristics are determined for the system in response to optimal maneuvering to nominal pointing following a momentum dumping procedure of the reaction wheels. The simulation identified the need to include the first resonant modes in the design model to ensure the system is robust in the presence of uncontrolled higher frequency modes and modeling errors.
