Moving-Gimbal Effect Suppression of MSCMG Based on Fractional-Order Disturbance Observer

During the frame motion of the magnetically suspended control moment gyroscope (MSCMG), a load torque acting on the Active Magnetic Bearing (AMB) system is generated, which interferes with the AMB rotor system and will amplify the jitter of the rotor displacement signal. In order to weaken the effect of load torque on the suspension stability of MSCMG, a torque interference suppression method based on a fractional order disturbance observer is introduced. First, the dynamic model of the AMB rotor system and the load moment model under the condition of frame rotation are established. Then, the principle of the disturbance observer (DOB) to suppress the interference torque of the frame is introduced, and the design of the fractional Q filter is realized by using the Oustaloup algorithm, which improves the fractional-order of DOB bandwidth adjustment. Finally, the simulation outcomes manifest that this method can successfully suppress the external interference caused by the load torque, enhance the anti-interference ability and enhance the stability of the AMB rotor system.