Precision tracking control of dual-stage actuation system for optical manufacturing

Abstract

Actuators with high linear motion speed, high positioning resolution and long motion stroke are needed in many precision machining systems. In some current systems, voice coil motors (VCMs) are implemented for servo control. While the voice coil motors may provide long motion stroke needed in many applications, the main obstacle that hinders the improvement of the machining accuracy and efficiency is its limited bandwidth. To fundamentally solve this issue, we propose to develop a dual-stage actuation system that consists of a voice coil motor that covers the coarse motion and a piezoelectric stack actuator that induces the fine motion to enhance the positioning accuracy. A flexure hinge-based mechanism is developed to connect these two actuators together. A series of numerical and experimental studies are carried out to facilitate the system design and preliminary control development.