Semiactive balancing control scheme for a rotor bearing system on MR dampers

In this paper is addressed the problem of semiactive balancing control of a Jeffcott-like rotor system on journal bearings, one of them supported on radial Magneto-Rheological (MR) dampers. The mathematical model of the rotor system results from a Jeffcott model and the dynamics associated to the MR dampers, whose properties depend on the current inputs (control actions). There are different models for MR dampers proposed in the literature, most of them experimentally validated. For control purposes we use the Choi-Lee-Park polynomial model, which is quite consistent with the nonlinear and complex hysteresis damper models and also simplifies the physical implementation. The semiactive control scheme is then analyzed and synthesized to manipulate the unbalance response of the rotor system, by means of a proper modification of the rotordynamics coefficients (damping and stiffness) using.sliding-mode control techniques.