Proposal of attitude control for high-precision stage by compensating nonlinearity and coupling of Euler´s equation and rotational kinematics

High-precision stages are used for the fabrication of integrated circuits, liquid crystal displays and so on. Since higher integration density and product quality are continuously required for the development of industry and informatics, not only the stage position but also the stage attitude needs to be controlled rapidly and precisely. The attitude is determined by roll, pitch and yaw motions which are affected by nonlinearity and coupling caused by Euler´s equation and rotational kinematics. These effects deteriorate the attitude control performance. This paper proposes a MIMO nonlinear feedforward attitude controller which compensates such effect. The effectiveness of the proposed approach is verified by simulations and experiments.