抄録
Rotating machinery has two major vibration problems caused by mass imbalance of a rigid rotor. One is whirling motion of the rotor. The other is vibration of the housing. Magnetic bearings can solve these problems by controlling the forces of electromagnets. As an example, the authors propose application of periodic learning control (PLC) with inverse transfer function compensation (ITFC), which can deal with periodic disturbances. When rotor displacement is treated as the output of the controlled magnetic bearing system, the PLC with the ITFC can suppress the whirling motion. When coil-currents are treated as the output of the controlled system, the PLC with the ITFC can reduce synchronous fluctuations of coil-currents. The reduction of the fluctuations of coil-currents results in the reduction of housing vibration. The PLC with the ITFC can carry out accurate compensation even when parameters of the controlled system are not accurately identified. The experimental results with a totally active magnetic bearing spindle are introduced.
