2019 Volume 17 Issue 3 Pages 371-379
This paper considers a rest-to-rest spacecraft attitude maneuver using two variable-speed control moment gyros. Two methods are used to derive angular momentum and gimbal angles over time subject to physical constraints. The first is an analytical method using variational calculus: from the analytical solution the dynamic characteristics of the attitude maneuver are easily understood and feasible trajectories are derived. The second is a numerical method which uses a Chebyshev pseudospectral method. The maneuvering time is minimized by the numerical method. In this second method, it is difficult to obtain a solution without appropriate initial values. However, a solution can be derived by using an analytical solution as initial values. The analytical and numerical methods are executed in all directions of the attitude maneuver, thus validating the effectiveness of the successful completion of the intended maneuver. Finally, ground experiments are conducted using the optimal trajectories obtained by the numerical method.