Identification The Stiffness And Damping Of AMB From Rotor Responses Due To Imbalances

AMB（Active Magnetic Bearing）is a kind of new high-performance bearing, in which the rotorcan be stable and frictionless suspended in space. The stiffness and damping of AMB have veryimportant influence to the dynamic characteristic of the AMB system. However, there is no method,which is mature and general to determine the stiffness and damping of AMB nowadays. This paperdescribes a method to identify equivalent stiffness and damping of AMB from rotor dynamic responsedue to imbalances.Build finite element model of the ABM system by MSC.Patran. Detail the modeling method ofthe finite element of rotor of AMB. Introduce how to improve the degree of exactitude of the finiteelement of rotor in MSC.Patran and how to add imbalance mass in rotor.After then, design a scheme to determine the stiffness and damping of AMB due to the imbalanceresponse. The formulas of determining the stiffness and damping of AMB are derived. Simulate theidentification procedure with four cases by computer. According to the characteristics of imbalanceresponse signals that are recorded by experiments, the paper develops a suitable FIR low-pass filter toget the target vibration signal. Then, test and verify the filter by MATLAB. The result shows that thefilter is effective and reliable.At last, the paper focuses on the experiment of the identification of the stiffness and damping ofthe AMB. In order to verify the reliability of the determining method, give the finite element model ofrotor the coefficients those are determined by the experiment, contrast the imbalance response ofsimulation and experiment. The method is proved feasible to determine the stiffness and damping ofAMB.