Suppression of Isolation Table's Fluctuation Due to Switching of Feedforward Controller

Abstract

To avoid a longer settling time of an isolation table, switching of the feedforward controller which is used for the control of supplied air's disturbances, is needed after starting and prior to stopping the table. However, this switching also causes the fluctuation of the table. In order to suppress the fluctuation of the table caused by switching, this study uses a difference operator before the feedforward compensator and the combination of feedforward and feedback loops. The effectiveness of this method is experimentally demonstrated.