Feasibility study & system conceptual design for the spherical actuator

This paper reports on the development of a spherical actuator which is an innovative satellite attitude control device. The spherical actuator consists of a spherical rigid metal ball which can rotate around arbitrary axes by magnetic levitation and 6 electromagnets which are allocated in pairs at each axis. The study is motivated from the possibilities of high torque generation, mass reduction and long life time and limitations of the conventional attitude control device such as singularity problem in Control Moment Gyroscope and low torque generation in reaction wheel. As a seed project at KARI, the purpose of this year is to study the feasibilities of the system and to design conceptually for the spherical actuator. To be more specific, the experiment of magnetic levitation and rotating of the spherical ball in 1 axis are scheduled to finish this year. In this study, the concept of spherical actuator and the mathematical model for the spherical actuator is present. In addition, some simulation results and analysis for the design parameters are shown.