An Inchworm-type Multi-DOF Stage

Abstract

This paper describes an inchworm-type multi-degree-of-freedom stage, which consists of a platform, linear links and a base. The stage is based on a self-propelled Stewart-platform. We use six stacked-type piezoelectric actuators as the linear links. Six electromagnets are used in the stage. The electromagnets connect the linear links to the base and to the platform. This structure enables the Stewart-platfom to move on a surface by using the principle of an inchworm. The platform supported by the linear links is also operated by the principle of an inchworm, which enables the platform to rotate in the tilt directions. While the electromagnets fix the linear actuators on the base, the platform of the proposed stage realizes a precise multi-DOF motion. Design, principle, and control signals are described. The position and orientation of the moving platform is measured, and some experimental results indicate the feasibility of the proposed stage. The mechanism is effective for a precise positioning system which has a wide working area.