An adaptive total variation regularization method for electrical capacitance tomography

Electrical capacitance tomography (ECT) is a nonintrusive imaging technique for monitoring dynamics within a closed container. In this paper, an image reconstruction algorithm for ECT, termed Adaptive Total Variation Regularization (ATVR), is introduced. The ATVR algorithm reduces total image error while preventing loss of features of interest in fluid-air interface monitoring. Unlike traditional total variation regularization for ECT, ATVR allows the regularization factor to change during image reconstruction allowing the algorithm to achieve higher accuracy at discontinuous boundaries (such as fluid interfaces) for the same overall image error. ATVR doesn´t require additional iteration steps compared to traditional TVR and so is equally well-suited for the online monitoring of rapidly flowing fluids. Experimental analysis has been conducted on a custom-built ECT test bed and confirms the simulation results and demonstrates the application of the algorithm to the case where a dielectric working fluid (oil) is undergoing steady pumping.