Title page for ETD etd-07132004-161249


Type of Document Master's Thesis
Author Lennox, Scott Evan
URN etd-07132004-161249
Title Coupled Attitude And Orbital Control System Using Spacecraft Simulators
Degree Master of Science
Department Aerospace and Ocean Engineering
Advisory Committee
Advisor Name Title
Hall, Christopher D. Committee Chair
Schaub, Hanspeter Committee Member
Woolsey, Craig A. Committee Member
Keywords
  • Orbital Control
  • Spacecraft
  • Attitude Control
  • Coupled Control
Date of Defense 2004-07-07
Availability unrestricted
Abstract
Translational and rotational motion are coupled for spacecraft performing formation flying missions. This motion is coupled because orbital control is dependent on the spacecraft attitude for vectored thrust. Formation flying spacecraft have a limited mass and volume for propulsion systems. We want to maximize the efficiency of the spacecraft, which leads to minimizing the error introduced by thrusting in the wrong direction. This thrust direction error leads to the need for a coupled attitude and orbital control strategy. In this thesis a coupled control system is developed using a nonlinear Lyapunov attitude controller and a nonlinear Lyapunov-based orbital controller. A nonlinear Lyapunov attitude controller is presented for a spacecraft with three-axis momentum wheel control. The nonlinear Lyapunov-based orbital controller is combined with a mean motion control strategy to provide a globally asymptotically stable controller. The attitude and orbit control laws are verified separately using numerical simulation, and then are integrated into a coupled control strategy. The coupled system simulations verify that the coupled control strategy is able to correct for an initial relative position error between two spacecraft.
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