Research On Dynamic Balance Technique Of Satellite With Large Rotating Compoents

With the continuous development of new spacecraft,more and more attention is paid to the research of rotating component payloads.There is a mass eccentricity resulting from the presence of manufacturing process limitations and installation errors,which leads to unbalanced moment.This may seriously affect the overall operation of the system and even lead to satellite mission failure.Hence,for satellites with large rotating component,starting from the rotor unbalance characteristics,considering the coupling effect between the satellite platform and the payload,the characteristics of dynamic unbalance disturbance of large rotating component are clarified,and then a targeted effective control algorithm is sought.It is of great significance to realize high-precision attitude control of satellites with complex structures.The main research contents of the paper are as follows:On the basis of the attitude dynamic of the three axis stabilized satellite,the formula of the inertia force and the dynamic imbalance is derived to deal with the unbalanced rotating components.Considering unbalanced components as external disturbances,satellite attitude dynamic model has been updated.It is concluded that for the static unbalanced moment generated by the inertial force,the value is related to the eccentricity,rotational speed and installation position of the rotating components The dynamic unbalanced moment is related to the rotational speed and inertial product of rotating components.This disturbance led to the sinusoidal divergence of the attitude of satellite platform.Aiming at the coupling effect between satellite platforms and payloads,a fine dynamic model with large rotating components satellites is proposed based on multi-body dynamics.This model innovatively takes the gyro-torque,the relative movement between the rotating components and the satellite platform,and the control torques generated by the change of the angular momentum of the rotating components into consideration.It is noted that this model is not suitable for dynamic systems with energy loss.At the same time,combined with engineering practice experience,reaction wheel for absorbing angular momentum of the rotating components and the friction torque of the rolling bearing was considered.Simulation analysis shows that the disturbance has the characteristics of periodicity and fixed-phase deviation,and the control torques is quite large during acceleration phase.In order to achieve high-precision attitude control of satellites,a composite compensation controller is designed to compensate the control torques and reduce the impulse characteristics of the disturbance torque during the acceleration phase of the rotating components.In the cruise phase,a dynamic balance controller based on repetitive control is used to ensure the asymptotical convergence of the satellite attitude,and the attitude vibration of the satellite platform is effectively suppressed.The proposed semiphysical simulation system verifies the difference between the coupling torque of the payload and the satellite platform based on the reaction wheel drive and the motor drive.It is confirmed that the model does not suitable for dynamic systems with energy loss.At the same time,the experimental results show that the dynamic balance control algorithm based on repetitive control effectively suppress the unbalanced moment.