直線運動精度の超精密計測・制御 液面を基準とする場合

Abstract

The purpose of this research is to realize precise straight motion. The straight motion system used in the paper has an ability to control five degrees of freedom of a moving table; vertical and horizontal positions, and roll, pitch and yaw angles. For the purpose, two references are introduced; motion reference and absolute reference. Table motions are controlled relatively to the motion reference. A solid master is used for the motion reference because of its stability against changes of environment. A geometrical error of the motion reference causes motion errors of the table. To compensate these errors, motion errors relative to the absolute reference are measured. The paper proposes the liquid surface for the absolute reference. The liquid surface is used only to measure motion errors caused by the geometrical error because the liquid surface is not robust enough. After the compensation, straight motion accuracies of 0.2μm in vertical position, 0.1arc sec in roll angle and 0.3arc sec in pitch angle were achieved.