Design, modeling, and control of a large range 3-DOF micropositioning stage

The demand for large range three-degrees-of-freedom (3-DOF) micro/nanopositioning mechanisms has been increased recently for potential utilization in many applications. However, these mechanisms suffer from a large footprint and low motion accuracy, which severely affect their exploitation. In this paper, a compact mechanism is proposed to achieve a large workspace and a high motion accuracy. Leaf springs are adopted to realize a fully compliant mechanism and three Voice Coil Motors (VCMs) are used in actuation. The VCMs are enclosed within driving arms and the leaf springs are distributed in a multilevel design to improve the mechanism compactness. The analytical model is developed and a prototype is fabricated to examine statics, dynamics, and feedback performance. Moreover, a laser-based sensing approach is developed to capture the 3-DOF motion. Furthermore, a robust control technique is designed to improve tracking performance. Results show that this mechanism possesses a compact design with a large workspace. Also, high resolution and tracking performance are achieved.