Dynamic modelling and observation of micro-vibrations generated by a Single Gimbal Control Moment Gyro

Control Moment Gyros (CMGs) are commonly used as actuators of attitude control in spacecraft. Micro-vibrations generated by CMGs will influence the performance of high-sensitivity instruments on-board the spacecraft; however, the micro-vibration characteristics of CMGs are not yet clearly understood. This research focuses on dynamic modelling and observation of micro-vibrations generated by CMGs. Firstly, the energy method was employed to develop a theoretical model describing a Single Gimbal CMG (SGCMG). This model fully considers the compliance of the internal bearing systems and the coupled motions of the rotating flywheel and the gimbal. Secondly, the micro-vibration characteristics of a SGCMG were tested using the standard Kistler table. Finally, the theoretical model was validated by comparing it against the disturbance characteristics obtained from the experimental tests, which revealed that predictions of the theoretical model consistently predicted the results of experimental tests. Therefore, the model presented here can be used to predict the micro-vibration characteristics of a SGCMG. •We conduct micro-vibrations experiment tests of the Control Moment Gyro.•We discuss the micro-vibration characteristics of the CMG.•Disturbance outputs are closely related to the gimbal angle.•Flywheel imbalance and bearing irregularities are the two main disturbance sources.•An accurate analytical disturbance model of the CMG is proposed.