Modeling and Parameter Identification for Active Lubricated Hydrostatic Bearing-Rotor System

Active lubricated hydrostatic bearing-rotor system can achieve large bearing capacity, high motion accuracy, high anti vibration ability and long service life. Models from first principles are often complex and inaccurate caused by the discrepancy between the ideal hypothesis and the actual situation. And the multiple-input multiple-output (MIMO) characteristics of the system further increase the complexity of modeling, but the system requires low complexity dynamic model over its entire operating range. In order to solve the problem, this paper presents a modeling and identification method. Firstly, a segmented linear model is established in a small displacement of the shaft, and the parameters are solved by the prediction error method. The parameter variation law of the system is obtained by fitting identified system parameters. Then, the dynamic equation of the system can be obtained. Finally, the identified model is validated by impulse signals. The experimental results demonstrate the validity and accuracy of the identified model.