Test and Analysis of micro-vibrations generated by Large Control Moment Gyroscope

Control moment gyroscope (CMG) is widely used as an actuator of spacecraft attitude control Micro-vibrations generated by CMG will influence the performance of high-sensitivity instruments on-board the spacecraft; however, the micro-vibrations characteristics of CMG are not yet clearly understood. This paper concentrates on testing and analyzing the micro-vibrations produced by CMG. Firstly, for the massive weight of CMG, it is impossible to remove the influence of testboard’s inherent characteristic on CMG’s vibration disturbance cannot be isolated with improving testboard stiffness. Hence, a rigid CMG model was developed and used in the control experiment for comparing the modal test results of the CMG model and prototype. Secondly, considering the natural frequency of CMG should be different according to the vitiation of its rigidity and mass distribution, a CMG start up dynamic test was implemented to calculate the working CMG natural frequency. Finally, a dis turbing frequency test under multiple CMG gimbal angular speed was designed to calculate t he influence from the CMG gimbal angular and its rotation speed and to further provide data for whole satellite CMG vibration disturbance analysis.