Research On Multi-function Range And Thickness Measurement Method Based On Eddy Current Signal

The eddy current sensor based on the eddy current effect has the advantages of noncontact,simple structure,fast relative speed,and is not affected by the medium on the outer surface of the test piece.It is widely used in the ranging process of conductive materials.During use,it was found that the sensor was sensitive to factors such as the type,thickness,and curvature of the test piece,which affected the measurement accuracy.Therefore,it is of practical significance to study the specific influence process of these factors on the sensor and propose corresponding improvement methods.In this paper,through the method of combining finite element simulation and experimental verification,various factors affecting measurement accuracy are studied;in view of the influence of the wall thickness of the test piece on the measurement signal,a probe structure that can measure distance and wall thickness at the same time is proposed.The distance measurement process provides a reference for the wall thickness;in view of the influence of the curvature of the test piece on the measurement signal,a method of optimizing the compensation value is proposed to improve the measurement accuracy.The specific work content is as follows:First,based on the measurement principle of the eddy current sensor and the finite element modeling theory,the numerical models of three basic eddy current probe structures are established through ANSYS simulation software,and their respective range and thickness measurement accuracy are calculated.Based on the analysis of the accuracy of the probe structure,a multi-functional range and thickness probe structure with wider applicable conditions is proposed.Secondly,through finite element simulation,the influence of probe parameters,probe layout,specimen wall thickness,specimen curvature,specimen type and other factors on the eddy current signal are specifically analyzed,and reasonable experimental parameters are selected based on this.Based on the simulation data,a compensation value optimization method is proposed to improve the ranging accuracy of the curvature specimen.Finally,Through the establishment of an experimental platform,the actual measurement effect of the multi-function distance measuring thickness probe structure was verified,and the rationality of the compensation value optimization method was verified.Experimental results show that the probe structure is feasible,and the compensation value optimization method based on experimental data is effective.