Disturbance observer control method in DGMSCMG

To restrain disturbances produced by parameter variations and external disturbances in the axial magnetic bearing in the application of a double-gimbal control moment gyro (DGMSCMG), a disturbance observer control method is proposed, which integrated the H_∞ controller and the disturbance observer. This method considers parameter variations of the magnetic bearing and the effect of gimbals on the axial magnetic bearing. Consequently, the state space equation is changed to the form which can eliminate the disturbances. Then the robust controller is designed, which includes the disturbance observer design and robust H_∞ controller design. The stability analysis is given for the proposed controller. Experiments on the DGMSCMG verified the correctness of the proposed method.