Multi-mode control for an active isolation system with an elastic table

This paper proposes a reduced-order physical modeling method for controlling the multi-modes of vibration of an active isolation system with an elastic table. In the lightweight isolation table, the elastic modes appear on the isolation table in a lower frequency domain. In order to avoid the spillover phenomena, the reduced order model, which includes elastic modes, is used in this modeling method. In this study, a reduced order physical model, expressed by 5DOF systems for controlling the multi-modes for designing the controller, LQ control systems, and a two-degree-of-freedom control method with feedforward control are applied. Finally, the discrete model and the controller design are verified through numerical calculations and experimentation.