Active vibration isolation control for a multi-degree-of-freedom structure with uncertain base dynamics

This paper proposes a design method for an active vibration isolation controller for a multi-degree-of-freedom structure with uncertain base dynamics. It is demonstrated that a controller with a desired performance can be designed even if we don't know precisely the base dynamics by using the criterion function for the purpose of suppression of the interaction between the controlled structure and its base. In order to minimize this interaction we select the acceleration of the lowest mass of the controlled structure and the relative displacement between the lowest mass and its upper mass as the controlled variables. By simulations and experiments it is verified that the designed controller improves both the control performances and the robust performance under existence of the base dynamics with uncertainties.