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

电磁轴承系统中广泛采用的是模拟电路的PID控制器。这种系统虽然简单、价格低廉，但对柔性转子的振动控制能力不够。为了减小由电磁轴承支承的柔性转子的共振，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，需要对系统进行适当的控制，并在系统的各个环节中进行适当的控制。本文利用状态观测器设计了状态反馈控制器，使系统的模态阻尼得到改善，并在此基础上提出了一种基于状态观测器的系统状态估计方法，该方法只适用于周期性外力作用下的系统状态估计。另一种方法是利用状态观测器设计的逆系统状态估计方法，该方法中的外力与状态观测器相比不具有周期性。本文的研究结果表明，该方法是有效的在应用上述概念的实验系统中，验证了与模态速度相关的反馈控制具有改善机械系统在每个模态上的阻尼特性的能力。

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.