Active Disturbance Rejection Control Based on Electromechanical Tribo-Dynamic Model Compensation of Single-Gimbal Control Moment Gyroscope

A single-gimbal control moment gyroscope (SGCMG) plays a crucial role in the attitude control of small satellites. The precision of the rotational speed of the gimbal in the SGCMG determines the accuracy of the output torque for adjusting the attitude. When the gimbal rotates, the primary flexible components of the SGCMG, i.e., bearings, exhibit time-varying stiffness due to the large changes in the tribological properties of the ball raceway (lubrication status and contact characteristics), which, in turn, impacts the gimbal speed. In light of this, this article proposes a control strategy to reduce the impact of bearing flexibility on the rotational speed of gimbal. First, considering the tribological properties of the bearings, an electromechanical tribo-dynamic for a control moment gyroscope is established. Second, disturbances affecting the gimbal's motion are computed through sensors or dynamic equations, leading to the proposal of an active disturbance rejection control (ADRC) based on model compensation. Finally, through simulation and experimentation, and a comparative analysis with the traditional ADRC, the proposed control algorithm is demonstrated to enhance the dynamic response performance and disturbance rejection capabilities of the system.