Determination of initial parameters for inverse tomography transformation in eddy current tomography

Abstract

The paper presents approach for determination of initial values of optimized parameters for inverse tomography transformation in eddy current tomography. Inverse tomography transformation is optimization procedure where objective function is residual sum of square errors between measurement results and results of forward tomography transformation for optimized model. Current approach is based on optimization of tested objects’ cross section, which is described by 4 parameters – radius, defect width, depth and angular position. Paper focuses on determining initial values of radius and defects’ angular position. FEM-based forward tomography transformations were conducted for spindle with changing radius, as well as for spindle with different angular position of defect. Obtained results confirmed possibility of determination of those parameters, basing on amplitude measurements (for angular position of defect) and phase shift measurements (for objects’ radius).