Abstract
Ultra precision apparatus like semiconductor producing equipment needs the high accuracy at manufacturing. Therefore active isolation systems to avoid vibration transmitted from a vibration source to the precision apparatus are very important. This paper deals with the control system design for active isolation table^<[1][2][3]>. It aims at controlling vibration of the installed object and isolation table simultaneously. An experimental isolation table with flexible loaded object is built. The experimental system is modeled according to the reduced order physical modeling method. The parameters of the table are experimentally identified. Using the obtained model, control simulations are carried out by using feed-back controller designed according to sub-optimal control theory, absolute velocity feed-back control theory and feed-forward controller. The sub-optimal feed-back controller achieved good vibration damping effect, while the feed-forward controller effectively suppressed vibration transmission from ground. In order to evaluate the control performance on experimental system, control experiments are carried out and compared with simulation results. They agreed well and the effectiveness of presented modeling and controller design procedure is confirmed.
