An Image Reconstruction Method of ECT Based on Two-step Regularization Gauss-NewtonIterative Algorithm
ZHANG Lifeng1,2,CHEN Da1,2,LIU Weiliang1,2
1.Department of Automation, North China Electric Power University, Baoding, Hebei 071003, China
2.Baoding key Lab of State Detection & Optimization Regulation for Integrated Energy System, Baoding, Hebei 071003, China
Abstract:Electrical capacitance tomography (ECT) is a nonlinear problem and has serious ill-posed. In order to improve the accuracy of image reconstruction, an ECT image reconstruction method based on two-step regularized Gauss-Newton iterative algorithm is proposed. Aiming at the non-convergence problem of standard regularized Gauss-Newton iterative algorithm in image reconstruction, a two-step iterative method is introduced. The regularization matrix is improved, which improves the accuracy of estimation. Considering the dependence of Gauss-Newton algorithm on the initial value of iteration, homotopy algorithm is added. Finally, the simulation and static experiment are carried out, and compared with the linear back projection (LBP) algorithm, Landweber algorithm and Tikhonov regularization algorithm, the results show that this method can effectively improve the accuracy of image reconstruction.
LEDGER P D. hp-Finite element discretisation of the electrical impedance tomography problem [J]. Computer Methods in Applied Mechanics Engineering, 2012, 225-228: 154-176.
WEN L M, ZHOU M M, LI M, et al. Improved Tikhonov regularization method for Image reconstruction [J]. Atca Metrologica Sinica, 2018, 39(5): 679-683.
ZHANG L F, Dai L. Image reconstruction based on robust regularized extreme learning machine for electrical capacitance tomography [J]. Atca Metrologica Sinica, 2022, 43(8): 1044-1049.
FAN W R, WANG H X, HAO K H. Two-step iterative TV regularization algorithm for image reconstruction of electrical impedance tomography [J]. Chinese Journal of Scientific Instrument, 2012, 33(3): 625-630.
MA M, HE X F, LI M, et al. Research on ECT image reconstruction algorithm based on improved TSVD regularization [J]. Transducer and Microsystem Technologies, 2020, 39(4): 136-139.
TANG L M. Regularization modified Gauss-Newton method for solving NLS problem [J]. Geotechnical Investigation & Surveying, 2009, 37(6): 58-61.
SUN J T, TIAN W B, CHE H Q, et al. Proportional-integral controller modified Landweber iterative method for image reconstruction in electrical capacitance tomography [J]. IEEE Sensors Journal, 2019, 19(19): 8790-8802.
MA M, SUN M J. Image reconstruction algorithms of ECT system based on the modified linearized Bregman algorithm [J]. Atca Metrologica Sinica, 2021, 42(7): 879-884.