Attitude Control Method for High-Precision Stage by Compensating for Nonlinearity and Coupling Arising from Euler's Equation and Coordinate Rotation

Abstract

High-precision stages are implemented in the manufacturing processes for electronic devices such as integrated circuits and liquid crystal displays. The development of electronic equipment manufacturing industry requires increasingly higher levels of integration density; hence, not only stage position but also the stage attitude needs to be controlled rapidly and precisely. The attitude is determined on the basis of roll, pitch, and yaw motions, which are affected by the nonlinearity and coupling arising from Euler's equation and coordinate rotation. These effects degrade the attitude control performance. This paper proposes a multi-input multi-output nonlinear feedforward attitude controller which compensates for these effects. The effectiveness of the proposed approach is verified through simulations and experiments.