Resonance suppression method based on H_∞ mix sensitivity of CMG gimbal system

Aiming at the issue of mechanical resonance of the control moment gyro (CMG) gimbal system caused by the harmonic drive due to its flexibility and low damping characteristics, a vibration suppression method based on H_∞ mix sensitivity is presented. According to the dynamic model of gimbal system, the theoretical analysis of mechanical resonance is achieved and the resonance frequency point of gimbal system is described. At the same time, regarding of the torsion torque introduced by the harmonic drive as a load torque disturbance, a H_∞ mix sensitivity controller is designed to suppress gimbal resonance. Employing the CMG with 1 000 Nms rated moment, the simulation and experiment results are performed that the designed controller can effectively suppress the vibration of gimbal servo system and further greatly improve the angular precision of the gimbal system.