Design of an Attitude Control System for a Spacecraft with Propellant Slosh Dynamics

<p>The presence of propellant slosh dynamics in a spacecraft system during a maneuver leads to attitude control system (ACS) performance degradation resulting in attitude tracking errors and instability. As spacecraft missions become more complex and involve longer durations, a substantial propellant mass is required to achieve the mission objectives and perform orbital maneuvers. When the propellant tanks are only partially filled, the liquid fuel moves inside the tanks with translational and rotational accelerations generating the slosh dynamics. This research effort performs a comparative study with different optimal control techniques and a novel application of a model reference artificial immune system adaptive controller (MRAIS). A linearized model of a realistic spacecraft dynamic model incorporating propellant slosh is derived utilizing the mass-spring analogy. Simulations with the linearized models assist in control law development to achieve the control objective: to suppress the fuel slosh dynamics while obtaining the desired attitude. These control laws are then tested with the nonlinear equations of motion for a spacecraft with propellant slosh dynamics to evaluate the ability of the models to design an attitude control system. Monte Carlo analysis is also applied to characterize the performance of each controller and determine the most significant parameters that cause instability issues. The Model Reference Artificial Immune System has superior performance in comparison to the baseline optimal control systems and is more robust to system instabilities, actuator failures, and aggressive maneuvers.</p>

Name thesis:degree_name

Master of Science in Aerospace Engineering

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Aerospace Engineering

Year

2018

Author dc:creator

• Coulter, Nolan

• attitude control
• spacecraft
• slosh dynamics
• Aerospace Engineering
• Astrodynamics
• Space Vehicles

Repository record dc:identifier

https://commons.erau.edu/edt/424

OAI identifier oai:identifier

oai:commons.erau.edu:edt-1423