Vertical Vibration Control of an Active Vibration Isolation table loading Elastic Tower-like Object

Abstract

This paper deals with the control system design for active isolation table that loads a dynamical object. When elastic loads are put on the isolation table, vibration modes of the table are changed. Therefore, the controllers for the active isolation table should be designed taking account of elastic loads.In this research, an experimental active isolation table with an elastic load is built. Its dynamical model is identified by using experimental modal analysis or FEM analysis. A controller in horizontal direction is designed by using the model according to sub-optimal control theory, absolute velocity feed-back control theory and feed-forward control theory. It has been confirmed from previous research that good control performance in the horizontal direction can be obtained. In this research, to further improve the performance, the optimal controller was designed for vertical vibration and the performance was verified.