Convex Optimization for Power Tracking of Double-Gimbal Variable-Speed Control Moment Gyroscopes

This Paper addresses an integrated power/attitude control system for a spacecraft with two double-gimbal variable-speed control moment gyroscopes. Double-gimbal variable-speed control moment gyroscopes are of interest because a single device is a three-degree-of-freedom attitude actuator. A double-gimbal variable-speed control moment gyroscope has two gimbal axes and one variable-speed wheel. A primary advantage of adopting this actuator is to reduce the number of actuators, which leads to reducing the total mass and volume allocation within the spacecraft. In this Paper, first, the dynamical equations of motion of a spacecraft equipped with multiple double-gimbal variable-speed control moment gyroscopes are developed. Then, two types of steering laws are proposed for two double-gimbal variable-speed control moment gyroscopes. These steering laws attain three-axis attitude control and power tracking by using the wheels as energy storage devices while considering both singularity avoidance and wheel spin e...