Some aspects of vibration control. Part II: An optimal active controller.

The paper presents a theoretical method for determining the optimal correction to be introduced in a mechanical system. The active control of harmonic vibrations may be achived by applying a control unit which ought to reduce the vibration amplitude of the selected elements of the system. The proposed method makes it possible to determine the controller parameters which provide an optimum value of the chosen quality index. This criterion includes the reduction of weighted amplitudes of the elements on the one hand, and minimizes energy of the control signal on the other. The described method is suitable for determination of an optimum controller of turbine rotor vibrations caused by bearing oil whip, bearing oil whirl or aerodynamic forces. For the case of rotor self-excited vibrations of aerodynamic type the linear model of excitations was compared with the neural network method.