基于H_∞混合灵敏度的CMG框架谐振抑制方法

Resonance Suppression Method Based on H_∞ Mix Sensitivity of CMG Gimbal System

针对由谐波减速器的柔性、低阻尼引起控制力矩陀螺(control moment gyro,简称CMG)框架伺服系统产生机械谐振的问题,提出了一种基于H∞混合灵敏度的振动抑制方法。结合框架伺服系统动力学模型阐明了系统产生谐振的原理,分析了系统的谐振频率点,并将由于谐波减速器引起的谐波扭转力矩作为系统输出端的扰动,在速度环中设计了基于混合灵敏度的H∞控制器来抑制该扰动,从而抑制框架伺服系统的谐振。以1 000N·m·s的控制力矩陀螺框架伺服系统为研究对象进行仿真及实验,结果表明,该控制方法有效地抑制了框架伺服系统的机械谐振,提高了框架伺服系统的速率输出精度。

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,aH∞ mix sensitivity controller is designed to suppress gimbal resonance.Employing the CMG with 1 000Nms 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.