NONDESTRUCTIVE TESTING METHOD FOR ELECTRICAL CAPACITANCE TOMOGRAPHY BASED ON IMAGE RECONSTRUCTION OF ROTATING ELECTRODES

Abstract

The electrical capacitance tomography (ECT) is a visual nondestructive testing technology. The relative positional distribution between the electrodes and the phantom object affects the accuracy of the reconstructed image. To solve this problem, an image reconstruction method and image fusion algorithm of ECT system based on rotating electrodes are proposed. First, 4 image reconstruction algorithms are employed to reconstruct the experimental model, the Landweber iterative algorithm based on Tikhonov regularization presents the best performance. Then, by rotation the 12 electrodes 4 times, we can obtain 5 sets of capacitance data, and obtain 5 images. Finally, the fusion results can be obtained by performing the adaptive weighted fusion on these 5 images. Results show that the adaptive weighted image fusion method based on rotation electrodes improves the quality of reconstructed images and effectively reduces the artefacts.