Flywheel Vibration Isolation of Satellite Structure by Applying Structural Plates with Elastic Boundary Instead of Restrained Boundary  
[PERSON]  
1 State Key Laboratory of Mechanics and Control for Aerospace Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; [EMAIL_ADDRESS]. the wheel speed. Some disturbances include interactions between the harmonics and the structural modes of the wheel which result in large disturbance amplifications at some wheel speeds [7]. These vibrations constitute the primary source of interference that significantly impacts the design performance of payloads [8; 9; 10; 11]. In particular, for optical payloads, the impact of flywheel disturbance cannot be ignored and is difficult to eliminate. For satellites that require high attitude stability and accuracy, the suppression of flywheel vibration is crucial. Since the disturbance of the flywheel system is generally multi-directional, most isolation devices for flywheels employ multiple independent isolation rod units. They form a multi-degree-of-freedom isolation platform with a certain topology configuration to suspend and isolate the flywheel system. This isolation method has greater flexibility, better omnidirectional isolation performance, and higher reliability. For example, China's FY-4 satellite [12] utilized a 6-DOF (six-degree-of-freedom) passive isolation platform to isolate the flywheel's vibration. The GOES-R satellite launched by the United States in 2016 applied viscoelastic isolators to reduce the impact of the disturbance from its six flywheels and achieved significant attenuation of vibration above 50 Hz [13]. A double-layer passive isolation system based on viscoelastic material is used in China's Gaofen-3 optical satellite for flywheel disturbance suppression [5]. [PERSON] from India [14; 15] proposed a flexible isolation platform based on a folding beam structure, which can reduce the installation stiffness of the flywheel and effectively suppress the vibration disturbance. The WorldView-I and WorldView-II Earth observation satellites [16] launched by DigitalGlobe integrated eight isolation rod units with the CMG group. [PERSON] et al. [17] studied the influence of flywheel vibration on optical cameras. Results showed that a flywheel isolation platform with four metal rubber isolation components can reduce the optical axis angular displacement of the optical payload by over 50%. [PERSON] et al. [18] proposed a passive isolation platform composed of multiple folding beams and established an equivalent kinetic model of the flywheel and platform system. The model was validated through eigenvalue and frequency response analysis, demonstrating that it can effectively reduce the disturbance of the flywheel. Passive isolation devices reduce micro-vibration by lowering the system frequency and increasing structural damping, and their reliability has led to widespread use in engineering. However, recent research has focused on semi-active and active isolation platforms based on passive ones. For example, [PERSON] et al. [19; 20; 21] from JAXA developed a variable damping isolation device to reduce the radial disturbance force caused by rotor static unbalance. [PERSON] et al. [22] invented an active-passive integrated 3-DOF isolation platform capable of two translational degrees of freedom in the installation plane and one perpendicular to it. [PERSON] et al. [23; 24] created an active 3-DOF isolation micro-platform using fully active piezoelectric actuators designed with the lever principle. [PERSON] et al. [7; 25; 26] proposed a hybrid isolation platform with a positive Stewart configuration, utilizing voice coil motors and viscous dampers for support legs to suppress flywheel vibration. [PERSON] et al. [27] studied the dynamic parameters of the satellite active isolation platform based on genetic and differential evolution algorithms considering load and structural weight. [PERSON] et al. [28; 29] created the kinetic model for the satellite with a 6-DOF vibration isolation system.