Research On The ECT Image Reconstruction Algorithm Based On Iterative Optimization Method

Electrical capacitance tomography(ECT)is one of non-destructive testing technology which widely used to detect two-phase flow and multiphase.ECT system is composed of capacitance sensor and data-collecting transmissive system and computer for image reconstruction.The function of the sensor is to convert the information of the measured area into capacitance data;The function of data-collecting transmissive system is to acquire capacitance data and transmit it to the computer;The function of image reconstruction system is to reconstruct capacitance data into images.The focus of this paper is image reconstruction algorithm.In this paper,an image reconstruction algorithm for electrical capacitance tomography based on improved particle swarm optimization,particle swarm optimization and gravity search are proposed.The experimental results show that these new algorithms proposed in this paper can effectively improve the quality of reconstructed image of capacitance tomography.The main research contents are as follows:(1)This paper analyzses the principle of electrical capacitance tomography,discusses the positive and inverse problems in image reconstruction,analyzses of the relationship between sensitivity and image reconstruction,and analyzses the ill-posed problem of image reconstruction.(2)In this article takes the 8-electrode capacitance tomography system as the research object,the classical algorithm is used to reconstruct four common flow patterns,and then the results of various algorithms are analyzed to understand the advantages and disadvantages of various algorithms.(3)In this paper,Landweber algorithm was selected as the research direction,using particle swarm optimization algorithm optimize the results of Landweber algorithm.Analyzing the problems that arised by particle swarm optimization algorithm when it is applied to image reconstruction,and improving the basic particle swarm optimization algorithm,an image reconstruction algorithm-EPSO was proposed.And then,adding the gravity search algorithm to EPSO makes it has a fast convergence speed and better reconstruction results.