Structural Design of Permanent Magnet Momentum Sphere for Attitude Control of a Small-sized Spacecraft

With the increasing application of small spacecraft, the momentum actuator, the core component of its attitude control system, has received more and more attention. Most of the traditional momentum actuators are redundantly designed with multiple single-direction momentum structures. The structure is complex and the efficiency is low, which is not conducive to the long-term on-orbit operation of the small spacecraft. Aiming at the above problems, a permanent magnet momentum sphere (PMMS) is proposed. Firstly, the basic structure of PMMS is given, and the mechanism of cogging torque is expounded according to the structure. Then, the model of PMMS is established in ANSYS by using virtual displacement method. According to the design requirements of PMMS, the relevant structural parameters are simulated and analyzed to reduce the influence of the cogging torque, and the optimal parameters that meet the design requirements are obtained. The simulation results confirm the rationality and effectiveness of PMMS design.