Dual-Stage Feed Drive for Precision Positioning on Milling Machine

A positioning system with long stroke and high precision by dualstage control was designed. The focus was on combining the long-stroke travel range of linear stage with high-precision characteristics of piezoelectric actuators. The control method used in the system was dynamic compensation type, where the error from linear stage becomes the input to the piezoelectric actuators. Positioning error of 30 μm with single-stage control in a 1 mm stroke can be reduced to 2 μm by using dual-stage control. This technique can be implemented for high-precision positioning in manufacturing and machining systems.