Satellite Attitude Control System Using a Spherical Reaction Wheel

A reaction wheel is generally capable of providing single axial torque. Three separated devices were indispensable for controlling three-axis attitude of a satellite. The proposed system, which is called spherical reaction wheel, enables three-dimensional rotation of a spherical rotor and provides three-dimensional torque so that mounting only one proposed device can be sufficient to control three-axis attitude of a satellite. Furthermore, the system reduces size and weight of an attitude control system in comparison with the conventional system. To confirm the validity of the proposed device as an attitude control system, we conduct experiments concerning attitude control of a small satellite model with PID controller.