Study Of Electromagnetic Characteristic Of Sensitive Field And Image Reconstruction For Electrical Capacitance-Resistance Tomography Compound System

The key of automatic control system in sugar production is accurate measurement of the density and flow rate of sugar aqua. The electrical capacitance- resistance tomography compound system can provide visualizing information in sugar-boiling bottle online. The system has advantages of being simple in structure, non-invasion, high safety and fast in response etc, producing the dependable information for optimized control. So it is a promising technique in industry. The techniques of two subsystems (e.g. electrical capacitance tomography (ECT) and electrical resistance tomography (ERT)) are studied in this dissertation, including of the principles, electromagnetic characteristics of sensitive field, image reconstruction and image fusion etc. The works are as follows:1. Principles, system structures, technique characters and applications ofECT and ERT are analyzed in details. The compound system's advantage and application for visualization are proposed too.2. A software package based on MATLAB is designed. The software package has a friendly interface, including of simulation function by Finite Element Method (FEM) and the control function. It can analyze the electromagnetic characteristic of sensitive field, and complete image reconstruction and image fusion.3. A FEM model of sensitive field for ECT and ERT is established and verified. The electromagnetism characteristic of the sensitive field is analyzed, including of relationship between electrode number, mesh shape, mesh number and electromagnetism of sensitive characteristic in ERT; relationship between electrode number, degreed of angel and sensitivity distribution in ECT. The analysis of the experiment result lays a solid foundation on the compound system's application in the industry.4. Some typical image reconstruction algorithms of ECT and ERT are analyzed. The result shows that LBP algorithm is appropriate to on-line detection still. The reconstructed image is improved in order to show its characteristic parameter in stereoscopic space.5. The image fusion algorithms are analyzed at trial for the compound system. Since the image reconstruction algorithms of ECT and ERT are aiming at two-phase flow, these algorithms will produce mistakes in condition of three-phase flow environment. So it is important to adopt image fusionalgorithms. After the reconstructed images of ECT and ERT are completed respectively, image fusion algorithms are applyed to reshow the original sensitive field.