抄録
To reduce unbalance response of a flexible rotor suspended by electromagnetic bearings, two methods have mainly been investigated. One is the method of increasing damping of the mechanical system ; the other is the method of cancelling out unbalances. For the former method, PID control is generally used. Although PID control is very effective for reducing resonance vibration, in other ranges of rotational speed it yields little effect. On the other hand, with the latter method of open loop control, it is expected that unbalance response is greatly attenuated in all ranges of rotational speed. In this paper, we combine PID control and open loop control with a variable gain against rotational speed. PID control is needed to stabilize the rotor system and open loop control is used to reduce unbalance response. From calculated and experimental results, we find that the above method has greater capability of suppressing vibration of a flexible rotor than does ordinary PID control.
