Design of Precision Positioning Stage Driven by Voice Coil Motor with Integrated Active Eddy Current Damper

Abstract

A flexure-based precision positioning stage driven by voice coil motor (VCM) with integrated active eddy current damper (ECD) is proposed in this paper. This device is constituted of two identical VCMs, one ECD and one compound double parallelogram mechanism (CDPM). The VCM with Halbach permanent magnets (PMs) array is designed to yield a large driving force and low force ripple. The CDPM is selected as the flexure guide with the advantages of deterministic motion and high precision displacement transmission. The double-sided active ECD is proposed to suppress the residual vibration especially in the deceleration or stop motion process. Based on the analytical models and theoretical analyses of the VCM, the ECD and the flexure guide, the relationship between the input driving current and output displacement is obtained. Finite element analysis (FEA) is carried out to verify both the electromagnetic and dynamic performance of the designed stage. The results validate that the proposed stage can achieve a large motion range about $\boldsymbol{\pm 5\text{mm}}$, deliver the force-constant variation less than 2%, and possess a high bandwidth approximately 55Hz.