Design Of Electrical Capacitance Tomography Detection System Based On DSP

Process tomography plays a vital role in the measurement of multiphase flow which exists in industrial area in recent years,such as petroleum, chemical industry, energy sources and so on.This paper mainly studies electrical capacitance tomography(ECT)which belongs to process tomography.Electrical capacitance tomography have acquired attention from many scholars both at home and abroad at present , because of many advantages , ECT becomes one of two-phase flow measurement technology which has an expansive application . To study electrical capacitance tomography system based on 12 electrodes , this paper introduces the significance of two-phase flow measurement technology which apply to industrial technology and scientific research. And describes the the present status and development trend of ECT technology in domestic and international . Then mostly research of this paper are as follows:⑴Design the hardware of ECT system which based on the DSP TMS320F2812 and make in-depth researches on structure, working principles, features of capacitance tomography.⑵The capacitance transducer which based on 12 electrodes and the circuit of switch selector which controlled by DSP are designed and made.⑶Analyze the impacts of stray capacitances on detection circuit and choose a capacitance/voltage (c/v) converting circuit which is anti-stray capacitances circuit .⑷In the disposal of the c/v converting circuit's result,multiplication demodulation was adopted for acquisition of DC voltage signal which eliminating noise signal.Then the output signal of multiplication demodulation is filtered by butterworth low filter to clear high-frequency signal.⑸This paper apply DSP to data collection and processing, and sent to the computer through the serial port at last.