Optimal design and experimental performances of an integrated linear actuator with large displacement and high resolution

Abstract

These linear actuators with large displacement, high resolution and compact structure have played an important role in ultra-precision engineering and still attracted a lot of attentions for various applications. Thus, a new integrated linear actuator with above capacities, based on the principle of coarse-fine composite, is proposed and discussed in this paper. Owing to the integration of a new electromagnetic rotor drive (ERD) and a smart giant magnetostrictive drive (GMD), a larger displacement can be initially achieved and maintained by the driving of the ERD, whereafter a smaller displacement can be adjusted and refined by the GMD. The mechanism structure and working principle are presented and described detailedly. As the key part, mechanical analysis and dynamic modeling of the ERD are carried out and established, and structure optimization is also conducted for obtaining a better working environment. A prototype was manufactured and its main performance was tested through a series of experiments. The results confirm that with a compact size of $\phi43 \times 95\, {\text{mm}}\, (L)$ the maximum output displacement is 503 μm, and the movement resolution is up to 70 nm, proving the feasibility of precise positioning in ultra-precision engineering.