Spacecraft Angular Velocity Stabilization Using A Single-Gimbal Variable Speed Control Moment Gyro

Feedback controllers for the stabilization of the angular velocity vector of a rigid spacecraft using a single-gimbal Variable Speed Control Moment Gyro (VSCMG) are presented. Linearization of the equations of motion show that complete attitude stabilization is not possible via linear methods. Nonetheless, it is shown that the linearized angular velocity equations are controllable, and a simple LQR control law is used to locally asymptotically stabilize the angular velocity vector. A Lyapunov-based approach is subsequently used to derive a state feedback control law that globally asymptotically stabilizes the nonlinear angular velocity system.