Abstract
This work was carried out to develop a precision dual positioning apparatus, consisting of friction drive and piezoelectric actuator. In this apparatus, the piezoelectric actuator, designed for fine positioning, is mounted on top of the friction drive slide, designed for coarse positioning. Individual loops are closed by laser interferometer systems, with 2.5 nm resolution. The friction drive and piezoelectric actuator move together, using a kind of inchworm movement method, which the authors have proposed. The method makes it possible for this positioning system to have an over 100 mm stroke with 2.5 nm resolution and no backlash. In addition, this dual positioning system, using the inchworm movement method, is also valid for assuring a tool's continuous path (CP) control, with nanometer order accuracies, in forming three-dimensional surfaces, using a precision machine (precision lathe).
