The Application Of Landweber Scheme In EMT

Electromagnetic Tomography (EMT) technology is an industrial process imaging technology, which based on the principle of electromagnetic induction. The EMT system has the advantages of simple structure, low cost, fast response, non-invasive, non-contacting and safe, it has broad application prospects. The research of EMT image reconstruction algorithm is very important. However, because of the characteristics of soft field and three-dimensional field, it has many challenges to the research of EMT image reconstruction algorithm.By means of the finite element simulation of EMT forward problem, this paper researched the EMT image reconstruction algorithm, the contributions of this dissertation are as follows:Based on the research of EMT forward problem and inverse problem, the Finite element analysis of EMT forward problem and the image reconstruction algorithm, the paper proposed the Landweber algorithm with the initial value from LBP. And using the singular value decomposition (SVD), author derived an iterative representation formula for the Landweber scheme and consequently established the necessary and sufficiency of known convergent conditions, then the method of choosing relaxation coefficients was found. Finally, the reconstruction image were realized by LBP algorithm and the Landweber algorithm with the initial value as 0 and result from LBP, by using the simulation data, then the image reconstruction result were compared. In practice, we can see that the Landweber algorithm with the initial value from LBP could optimize the image reconstruction result.