| 摘要 |
<p>A magnetic bearing is provided with a simulating circuit (10) for estimating a displacement of a rotor (1) on the basis of a force which is exerted on the rotor (1). An output of the simulating circuit (10) is compared with an actual displacement signal. A delay circuit (13) and a subtracter (21) are provided to subtract a run-out which was estimated one period before the rotation of the rotor from the displacement signal. A displacement signal from which the run-out component was eliminated is set to a new displacement signal. A signal which is obtained by adding an estimation run-out of one period before, namely, an output of the delay circuit to the run-out which was estimated by comparing the output of the simulating circuit (10) with the new displacement signal is newly inputted to the delay circuit (13). Due to this, the run-out component is eliminated from the displacement signal of the magnetic bearing, a load of power amplifiers (7a, 7b) for driving electromagnets (3a, 3b) is reduced, there is a surplus for a saturation which is caused in a high frequency band, the reliability of a control system is improved, and a deterioration of a positional accuracy which is caused by the run-out is prevented. <IMAGE></p> |
