New Image Reconstruction Algorithm for Capacitively Coupled Electrical Resistance Tomography

As a new electrical tomography technique, capacitively coupled electrical resistance tomography (CCERT) has been recently proposed and investigated. Currently, the research works on image reconstruction algorithms for CCERT are still very limited. In this paper, a new image reconstruction algorithm for CCERT is proposed with the combination of the famous Levenberg-Marquardt (L-M) method and the simultaneous algebraic reconstruction technique (SART). The L-M method is used to obtain an initial reconstructed image. The SART is applied to obtain the final reconstructed image. With a 12-electrode CCERT system, the new image reconstruction algorithm is examined by simulations and experiments, respectively. Both the simulation results and the experimental results show that the images reconstructed by the new image reconstruction algorithm are satisfactory and are in accord with the actual distribution of the two-phase flows. Compared with the conventional image reconstruction algorithms for CCERT, the new image reconstruction algorithm can obtain better reconstructed images.

I. Introduction

By Introducing Capacitively Coupled Contactless Conductivity Detection (C⁴D) technique [1]–[5] into the research field of process tomography, a new electrical tomography technique termed Capacitively Coupled Electrical Resistance Tomography (CCERT) has been proposed and investigated recently [6]–[8]. It can reconstruct the conductivity distribution and hence the material distribution over the cross-section of conductive two-phase flows from boundary changes of electrical measurements. Compared with the conventional Electrical Resistance Tomography (ERT) systems, the CCERT system can avoid the electrochemical erosion effect and the polarization effect and hence eliminate the measurement errors caused by electrode contamination because the electrodes of a CCERT sensor are not directly in contact with the measured fluid [9]. Because of these advantages, the CCERT technique may have more broad application prospects than the conventional ERT technique in the future.