Robust QFT control of a three-axis nano-positioning stage

Abstract

A novel three-axis nano-positioning device is proposed which consists of an X-Y table and a rotational stage on top of the X-Y table. Each stage is actuated by piezoactuator and the motion is sensed by laser displacement sensors. The simplified model of the stage was derived and the finite element model was developed to analyze the motion of the stage. Then the QFT algorithm was proposed to design robust controllers for the stage. It was found that the rise time of the stage is about 0.1 sec for a 10 um input. The positioning accuracy can achieve is within 0.1 um.