Reducing Undesirable Vibration of Rotating Payload Connected to Spacecraft Using Magnetic Bearing

The control accuracy and stability requirements for rotating payloads in remote sensing satellites are becoming increasingly higher. Typically, rotating payloads such as cameras are connected to the satellite body through mechanical bearings. However, clearances in conventional mechanical bearings are inevitable due to assembly tolerances, manufacturing errors, and wear. When clearances exist in the mechanical bearings of cameras, the clearance between the mechanical bearing and the journal can cause impact-induced vibrations. This paper proposes the implementation of magnetic bearings instead of mechanical bearings to connect the payload with the spacecraft body. First, the magnetic bearing is modeled as a rotational joint with clearance in the dynamic system with magnetic constraints. Subsequently, radial and axial magnetic force models are established. Furthermore, a comparative analysis is conducted to investigate the effects of connection approaches, namely traditional mechanical bearing connections and magnetic bearing connections for rotating payloads. Simultaneously, the dynamic responses of rotating payloads under different connections are discussed. The simulation results demonstrate that the camera attitude motion accuracy is improved and the vibration amplitude under disturbance is reduced when using magnetic bearings. Consequently, the magnetic bearing can effectively isolate vibrations and mitigate disturbances, thereby significantly reducing the attitude shake of rotating payloads.