A Dual-Modal Tomography System Based On Internal Array Electrode

Electrical tomography technology provides an effective field parameters testing for two-phase flow system. Compared with other tomography technology, it has the advantages of non-radiant, rapid response and low cost.Electrical Resistance Tomography and Electrical Capacitance Tomography are the two most developed ET methods nowadays. ERT is suitable to measure the conductive medium that is taken as the continuous phase in two-phase flow, while ECT is suitable to measure the non-conducting medium that is taken as the continuous phase. Because of the set of constraints, It is difficult to accomplish the target just use one detection technology under complicated working conditions. It is of significant to combined with ERT and ECT and fuse their measured data, which has the advantages of expanding the scope of application and acquiring more information.In this thesis, the sensor structure optimization and hardware design of the dual-mode tomography technology are introduced and studied. The main work and results are as follows:1. Based on the analysis of the soft-field characteristics of the sensing field, Electrode array model of the3-dimensional dual-mode system is established by using the physical field coupling analysis software COMSOL, and optimum design of the electrode structure is obtained combined with sensor structure parameters optimization criterion. It can eliminate the interaction between two sensitive fields effectively.2. A novel16-electrode digitized dual-mode tomography system base on FPGA and DSP is designed and implemented, which can operate in either single mode or dual-mode. FPGA is responsible for the logical controls of the front end circuit and pre-processing of the signal. DSP mainly realize the function of data transfer, post-processing, algorithm realization and communication with PC.3. The system programming design was constructed. In order to facilitate the system debugging, the seamless link between MATLAB and the programming environment is realized through interface program design. 4. Performance test including the channels’consistency are implemented. Static experiments and flow pattern experiments are also studied. The results show that the system has the feature of good flexibility and expansibility.At the end of the thesis, the author presented some ideas to improve the system.