Stability improvement of motion of a rotor with an active control method

The so-called phase-locked delayed feedback control method is applied to a Jeffcott rotor supported by rolling-element bearings but with negative damp ing and then to the same rotor supported by journal bearings, to improve th e stability of motion of the rotor. The control parameters are determined i n terms of the characteristic equation of the controlled rotor. The results of numerical simulations show that the stability of motion of the rotor is greatly improved with the help of the phase-locked delayed feedback contro l method.