Research On Image Reconstruction Algorithm Of Electrical Resistance Tomography

Flow imaging is a new technique delevoped rapidly in recent years, which has great developmental potential and wide industial application prospect. Having many distinct advantages such as low cost, wide application field, simple structure, non-invade and better safety, Electrical Resistance Tomography(ERT) has being the most popular research direction and the main development in flow imaging technique. There is still a lot of work to be done before practical use of the technique.The object of this dissertation is on the research of 16-electrode Electrical Resistance Tomography system. The topics studied are: modeling and analyze using Finite Element Method, analyse and computation of sensitivity field, optimal design of transducer, identification of the pattern of two-component flow, image reconstruction of the discrete phase distribution, concentration measurement. The main problems researched in the dissertation and achievements are as follows:Firstly, the important meaning of multiphase flow measurement to the science research and industry production is summarized, at the same time main parameter, current status and developing trend of multiphase flow measurement technique are analyzed.Secondly, the structure and technique characteristic of electrical resistance tomography system is clarified. The current status and broad industrial application prospect of electrical resistance tomography are discussed. The key problems that must be solved in the development of electrical resistance tomography are also pointed out. It is emphasized that the soft field characteristic and the low resolution of image reconstruction are the main problems that result in the difficulty of its practical application.Thirdly, the principle and constitution of electrical resistance tomography system is analyzed and mathematical model of sensitivity field is proposed. The current status of ERT technique is discussed. The system of finite element is built, and it can calculate numerical value of sensitivity field.Fourthly, introduce several classical ERT image reconstruction algorithms, analyse and compare these excellences and disadvantages, in an attempt to inherit and improve.Finally, Neural Network is used as ERT image reconstruction algorithm.Put forward a new kind neural network called algebraic neural for ERT, MATLAB simulation results show the method is effective and accurate for image reconstruction.