MINIMUM ELECTRICAL ENERGY SPACECRAFT MANEUVERS: THEORY AND EXPERIMENTS

Abstract

Reaction wheels are popular satellite attitude control actuators that have been the subject of years of research. Recently, optimal control theory was applied to discover a new reaction wheel control algorithm that steers the spacecraft along an alternate path, minimizing power draw for a system of redundant (four or more) reaction wheels while completing a shortest-time maneuver. This thesis characterizes the energy draw of a particular slewing maneuver using both a conventional attitude maneuver trajectory and trajectories derived using the new concept. In particular, a minimum energy optimal control problem is solved to find efficient energy profiles for a realistic reaction wheel spacecraft attitude control system. These profiles build a maneuver cost tradespace, validating the nonlinear relationship between electrical energy consumption and maneuver duration. To bridge the gap between theory and practice, an experiment is also implemented to test the solutions involving a set of reaction wheels to measure power consumption. Ultimately, an optimal maneuver operating envelope is created and the power model is verified to accurately characterize the power draw of a momentum exchange attitude control system.