Backstepping Control for Satellite Attitude Control Using Spherical Control Moment Gyro

This paper proposes a design of a controller of the spherical control moment gyro (CMG) system that was developed gimballess structure. Generally, it is required to apply the complex steering law to CMG to avoid or pass the singularity that is caused by the gimbal system. Therefore, we proposed a novel system that can reduce the singularity by applying a sphere instead of the gimbal structure. The spherical rotor containing flywheel is driven by three pairs of omni wheels attached to DC motors. In our previous study, the effectivity of the proposed system has been confirmed. Then, this paper applied the backstepping controller to the spherical CMG system because the backstepping is useful control logic for the proposed system having a cascade structure. We designed the controller based on the redesign Lyapunov function, and the validity of the proposed controller is confirmed through numerical simulation.