Disturbance characteristics analysis of CMG due to imbalances and installation errors

The control moment gyroscope (CMG) is used as the actuator of attitude control for modern satellites. Because of static and dynamic rotor imbalances and installation errors, it becomes one of the main vibration sources on a satellite. To provide a quiet environment for optical payloads, CMG disturbance characteristics due to imbalances and installation errors are analyzed, and the application of the CMG on remote sensing satellites is discussed. In the first step, we construct the dynamic CMG model according to the Newton-Euler approach, taking the static and dynamic imbalances and installation errors of the rotor into consideration. This dynamic model is analyzed in detail, and the axial dynamic equation of the gimbal and that of the rotor are derived. The validity of this model is analyzed and tested by numerical simulation. A cluster of CMGs is adopted, and the integrated satellite dynamic model is derived. In the third part, we analyze the influences of disturbances caused by CMGs on attitude precision and stabilization of satellites. To meet the requirements of attitude precision and attitude stabilization for remote sensing satellites, the constraint conditions of the CMG performance indexes are obtained.