A gyroscopic rotor exposed to unbalance is studied and controlled with an active piezoelectrical bearing. A model is required in order to design a suited controller. Due to the lack of related publications utilizing piezoelectrical bearings and obtaining a modal model purely exploiting experimental modal analysis, this paper reveals a method to receive a modal model of a gyroscopic rotor system with an active piezoelectrical bearing. The properties of the retrieved model are then incorporated into the design of an originally model-free control approach for unbalance vibration elimination, which consists of a simple feedback control and an adaptive feedforward control. After the discussion on the limitations of the model-free control, a modified controller using the priorly identified modal model is implemented on an elementary rotor test-rig comparing its performance to the original model-free controller.

A gyroscopic rotor exposed to unbalance and internal damping is controlled with an active piezoelectrical bearing in this paper. The used rotor test-rig is modelled using an FEM approach. The present gyroscopic effects are then used to derive a control strategy which only requires a single piezo actuator, while regular active piezoelectric bearings require two. Using only one actuator generates an excitation which contains an equal amount of forward and backward whirl vibrations. Both parts are differently amplified by the rotor system due to gyroscopic effects, which cause speed-dependent different eigenfrequencies for forward and backward whirl resonances. This facilitates eliminating resonances and stabilize the rotor system with only one actuator but requires two sensors. The control approach is validated with experiments on a rotor test-rig and compared to a control which uses both actuators.