A semiactive control scheme for a 6-DOF model of a rotor-bearing system with a MR suspension

This work deals with the problem of balancing control of a rotor-bearing system, which consist of one rotor mounted on two nonorthotropic supports, one of them a traditional journal bearing and the other a journal bearing supported by an arrangement of two radial magneto-rheological (MR) dampers, whose rheological properties depend on the current inputs. The mathematical model of the 6 degrees of freedom rotor-bearing system consists of one disk with unbalance mounted on a shaft and two nonorthotropic supports. For control design purposes a Choi-Lee-Park polynomial model is considered for the two MR dampers, which are quite consistent with the nonlinear and complex hysteresis behavior and also simplifies the implementation issues of the balancing control scheme. The controller for the unbalance response is synthesized using sliding-mode control techniques. Finally, some simulation results are reported to illustrate the dynamic performance of the overall open-loop and closed-loop system.