Here, the electromagnetic force of a differential magnetic suspension active isolator which was the core component of a magnetic suspension active vibration isolation system was measured by means of experiments. Through experimental measurements and fitting a mathematical expression with least square method, the actual relation expression of electromagnetic force-current-gap was obtained. A control mechanism and a value function for active vibration isolation based on force transmissibility were proposed. Considering the practical capacity of the differential magnetic suspension active isolator, the value function was revised. The revised function and the optimal feedback matrix were deduced. A control model based on the control mechanism was established. Output force responses of the active vibration isolation system and a passive one under wxcitation of swept-frequency signal were simulated. The simulation results indicated that the active system possesses good effect on vibration isolation. comparing with the passive system, the force transmissibility is reduced by 2-3dB in low-frequency range, especially, around the resonance frequency, the force transmissibility is reduced by 8-10dB. In order to check test the reliability of the mechanism, experiments were performed. Experiments showed that the force transmissibility is reduced by 6-8dB around the resonance frequency, so the experimental results agree well with the simulated results.
SONG Chunsheng;Hu Yefa;Zhou Zude .
Control mechanism of a differential magnetic suspension active vibration isolation system[J]. Journal of Vibration and Shock, 2010, 29(7): 24-27,1
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