DIGITAL VIBRATION CONTROL AND BALANCING FOR A FLEXIBLE ROTOR SUSPENDED BY MAGNETIC BEARINGS

在主动电磁轴承系统中，广泛使用的是具有模拟电路的PID控制器。虽然该系统结构简单、价格低廉，但对柔性转子的振动控制能力不足。为了减小柔性转子的共振振动，基于近似降阶模型设计的状态反馈控制是有效的。为了实现这种控制，不平衡力的估计是必要的。一种常用的状态估计方法称为状态观测器，这种方法只有在外力是周期性的情况下才有效。另一种方法是逆系统，与状态观测器相比，外力不必是周期性的。在本研究中，利用这些估计器，我们设计了状态反馈控制器，使得能够独立地改善机械系统的模态阻尼。在应用上述概念的实验系统中，验证了与模态速度有关的反馈控制具有改善机械系统在每种模式下的阻尼性的能力。

The PID controller with an analog circit is widely used in the active magnetic bearing system.Although this system is simple and non-expensive, the ability of vibration control for a flexible rotor is not sufficient.To reduce resonance vibrations of a flexible rotor suspended by active electromagnetic bearings, the state feedback control whose design is besed on an approximate reduced-order model is effective.For a realization of this control, it is necessary to estimate unbalance forces.One method which is often used for estimating the state is so called a state observer and this method is vallid only for external forces being periodic.The other method is an inverse system in which external forces have not to be periodic in comparison with a state observer.In this research using these estimator we design the state feedback controller which enables to improve modal damping of the mechanical system independently.In the experimental system applied above concept, it is verified that the feedback control which relates a modal velocity has a capability to improve a dampimg property of the mechanical systemon each mode.