Development of a Novel 3-DOF Positioning Stage for Ultra-precision Grinding (1st Report) -Simple Model and Experiment-

This paper shows a development of a novel 3-DOF positioning stage for ultra-precision grinding machine. The stage utilizes three stacked piezoelectric (PZT) actuators to control the orientation errors of the moving part and to improve stiffness. For purpose of eliminating the hysteresis of PZT actuator and improving the property of response, three high positioning sensors (capacitive sensor) are used for the closed loop control and three flexure hinges are designed as guide. Not only the structure of flexure hinge but also the location of each flexure hinge on the moving platform is also elaborately designed in order to provide the sufficient pre-load and minimize the bending deformation of ultra-precision positioning stage. On the basis of static and dynamic model developed, the algorithm for closed loop control is proposed by own. Finally, the experiments have been carried out to evaluate the static and dynamic performance of the stage and the results show that the static and dynamic models proposed are in well agreement with the experiment results and 4nm resolution can be achieved.