The ultra-precision positioning system is demanded for some industrial fields, such as semiconductor lithography and fabrication of the nano structure. In this paper, the ultra-precision stage which consists of flexure hinges, piezoelectric actuator, ...
The ultra-precision positioning system is demanded for some industrial fields, such as semiconductor lithography and fabrication of the nano structure. In this paper, the ultra-precision stage which consists of flexure hinges, piezoelectric actuator, and ultra-precision linear encoder, is designed and developed. From the step responses of the system, the system transfer function of the ultra-precision stage system was derived by a second order model system. In order to have robustness for the system uncertainty and external disturbances, the weighting functions were selected and the H∞ controller was designed using them. For the designed controller, the simulation was performed and the designed stage system was applied. Experimental results found that this stage could be controlled below 5㎜ resolution and irrespective of hysteresis and creep by this designed controller.