Shape reconstruction method for imaging conductive materials in Electrical Capacitance Tomography

One of the innovative application of the tomography process is detecting the size and the location of the grounded metal in the Lost Foam Casting (LFC). Traditional methods based on fixed sensitivity matrix for solving the inverse problem are failed while the other dynamic methods for updating the sensitivity matrix are consuming time. A design of a narrow band level set method to reconstruct the interfaces between the grounded objects and the foam patterns is discussed. The level set method is a well suited method compared with the traditional pixel based image reconstruction methods for the case of the grounded metal. This method can provide more accurate solution for recovering the shape and the place of the grounded metal. Two difficult problems are associated with the ECT system for the grounded material, sensitivity matrix calculation and the shielding problem. The effect of the grounded metal on the sensitivity matrix is studied and the shielding problem is demonstrated. The final results, based on simulations, demonstrate the advantage of using the shape reconstruction method to track the shape and the location of the grounded metal in the imaging area.

[1]  Lihui Peng,et al.  Image reconstruction algorithms for electrical capacitance tomography , 2003 .

[2]  Mohamed Abdelrahman,et al.  Monitoring metal-fill in a lost foam casting process. , 2006, ISA transactions.

[3]  M. Soleimani,et al.  Level set reconstruction of conductivity and permittivity from boundary electrical measurements using experimental data , 2006 .

[4]  F. Santosa.  A Level-set Approach Inverse Problems Involving Obstacles , 1995 .

[5]  Ø. Isaksen,et al.  A review of reconstruction techniques for capacitance tomography , 1996 .

[6]  F. Santosa,et al.  Reconstruction of a two-dimensional binary obstacle by controlled evolution of a level-set , 1998 .

[7]  M. Burger.  A framework for the construction of level set methods for shape optimization and reconstruction , 2003 .

[8]  E. Miller,et al.  A shape reconstruction method for electromagnetic tomography using adjoint fields and level sets , 2000 .

[9]  Ronald Fedkiw,et al.  Level set methods and dynamic implicit surfaces , 2002, Applied mathematical sciences.

[10]  J. C. Gamio,et al.  A comparative analysis of single- and multiple-electrode excitation methods in electrical capacitance tomography , 2002 .

[11]  William R B Lionheart,et al.  Reconstruction Algorithms for Permittivity and Conductivity Imaging , 2001 .

[12]  T. Chan,et al.  Level set and total variation regularization for elliptic inverse problems with discontinuous coefficients , 2004 .

[13]  J. Sethian.  Numerical algorithms for propagating interfaces: Hamilton-Jacobi equations and conservation laws , 1990 .

[14]  Eric T. Chung,et al.  Electrical impedance tomography using level set representation and total variational regularization , 2005 .

[15]  Thomas Sonar,et al.  On a second order residual estimator for numerical schemes for nonlinear hyperbolic conservation laws , 2001 .

[16]  J. Sethian,et al.  Fronts propagating with curvature-dependent speed: algorithms based on Hamilton-Jacobi formulations , 1988 .

[17]  K. Kunisch,et al.  Level-set function approach to an inverse interface problem , 2001 .

[18]  S. Osher,et al.  Algorithms Based on Hamilton-Jacobi Formulations , 1988 .

[19]  S. Osher,et al.  Level Set Methods for Optimization Problems Involving Geometry and Constraints I. Frequencies of a T , 2001 .

[20]  Manuchehr Soleimani,et al.  Nonlinear image reconstruction for electrical capacitance tomography using experimental data , 2005 .

[21]  Sun Li-quan.  Simulation of Sensors and Image Reconstruction Algorithm Based on Genetic Algorithms for Electrical Capacitance Tomography System , 2004 .

[22]  Stanley Osher,et al.  A survey on level set methods for inverse problems and optimal design , 2005, European Journal of Applied Mathematics.

[23]  Manuchehr Soleimani,et al.  Image and Shape Reconstruction methods in Magnetic Induction Tomography and electrical impedance tomography , 2005 .

[24]  James A. Sethian,et al.  Level Set Methods and Fast Marching Methods , 1999 .