Study On A High-speed Communication System For Electrical Capacitance Tomography

Two-phase flow widely exists in industries. The real-time and accurate measurement of two-phase flow parameters is significant in the industrial application. Because of the complexity, nonlinear and dynamic characteristics of the two-phase flow system, the measurement of two-phase flow parameters becomes a difficult and urgent problem to be solved.Electrical Capacitance Tomography (ECT) is a widely studied technique for the measurement of two-phase flow parameters. Owing to the advantages of low-cost, high-speed capability, non-invasion, wide applications and reliability, ECT has been applied in many fields. However, it is still in the stage of laboratory research due to a few problems and difficulties.Based on the analysis of existing ECT system, a high-speed communication system for ECT is proposed and developed. Test results show that the data transmission rate can meet the real-time requirement of the industrial processes.The main works are listed as follows:(1) By analyzing the widely used capacitance measurement circuits and communication methods used in ECT, a high-speed communication system based on Universal Serial Bus (USB) 2.0 is designed and developed. The advantages of the present ECT data acquisition circuit are fully developed and the "bottleneck" of data communication in ECT system is broken through.(2) The Digital Signal Processor (DSP) has been applied in the new system. Using thedeveloped firmware program and application program, the communication between DSP and host computer based on USB is implemented.(3) The data transmission rate and reliability of the designed system are tested and theresults meet the requirements of application. Some suggestions are proposed for the further design of high-speed and reliable ECT system.