Development of a three-axis active vibration isolator using displacement cancellation technique

Abstract

A three-degree-of-freedom (3-DOF) active vibration isolation system using vibration cancellation technique is presented in this paper. The disturbance cancellation concept is put into action to design the controller as well as to eliminate the displacement of the isolation table respect to the base under static load. The corresponding controller is designed in such way so that it can generate additional opposite force against disturbance. This additional force just makes the movement of the isolation table along the opposite direction of the disturbance to cancel the effect of the middle table movement on the isolation table, which finally leads zero compliance of the isolation table. Voice coil motors (VCMs) are used for getting linear actuating effect of the system's moving parts. The developed system under mode control showed the capability to maintain zero compliance under static disturbance in the 3-DOF motions associated with horizontal translations and a vertical rotation. Moreover experiments have been conducted to measure the dynamic response of the controlled system associated with direct disturbance.