Harmonic response of an eddy-current sensor for real-time measurement of thin-wall titanium alloy workpiece
Journal
IEEE/ASME International Conference on Advanced Intelligent Mechatronics
Journal Volume
2016-September
Pages
1271-1276
Date Issued
2016
Author(s)
Abstract
Motivated by the needs to develop a sensing method that simultaneously characterizes the dynamic behavior and system properties for analyzing and controlling a physical system, this paper formulates the harmonic response of an eddy-current (EC) sensor using the distributed current source (DCS) models to determine the workpiece thickness and displacement from the measured magnetic flux density of the induced EC. The DCS modeling methods, which base on physically intuitive closed-form solutions to derive the response to an input current through an electromagnet, do not require time-consuming and complicated meshes including the air-space as needed for a finite-element analysis. The effectiveness of the closed-form approximation for real-time applications has been verified against exact integral solutions and finite-element analysis (FEA), which requires less than 1% of the exact integral computation and yet is capable of achieving relatively high accuracy of about 2% maximum error. The models have been applied to derive a mapping between experimentally measured harmonic response of the induced EC field and the thickness/displacement of a titanium alloy workpiece.
Type
conference paper