Key Technology Research And System Development Of EMT Remote Experimental Platform

Electromagnetic tomography technology is applied for non-destructive testing,geological investigation,non-contact monitoring and positioning of exceptional object,as well as non-destructive rail testing and so on.With the wide application of electromagnetic tomography,the complexity of experimental equipment and the dependence of imaging process on equipment hinder the further development of electromagnetic tomography technology.Based on this situation,a remote experimental system of electromagnetic tomography is developed in this thesis,which provide a remote experimental platform,so that researchers do not need to build the experimental system by themselves,they can operate the electromagnetic tomography experiment remotely,and choose different image reconstruction algorithms to obtain the results of image reconstruction,finally,the experimental results of electromagnetic tomography will be displayed on the website page.The research content of this thesis can be divided into the following parts:(1)The quality of image reconstruction in electromagnetic tomography is improved.The most core and difficult problem of electromagnetic tomography technology is image reconstruction,because it is an important factor which determine the result of electromagnetic tomography.Therefore,the key point of electromagnetic tomography is how to improve the quality of image reconstruction by the study of image reconstruction algorithms.In this thesis,the remote experimental platform will get the results of image reconstruction on the web page ultimately,so the key to the results of the experiment is the final image reconstruction effect.In this thesis,the traditional image reconstruction algorithms are studied firstly,and then a new image reconstruction algorithm named Split-Bergman algorithm is proposed.The simulation and experimental results show that the Split-Bergman algorithm effectively improves the image reconstruction quality and make the imaging process faster.(2)The hardware experiment platform of electromagnetic tomography is built,including the research and analysis of sensor array,the selection and design of signal excitation and acquisition unit,and the design of channel switching circuit.Finally,the eight coil circular sensor is used as the sensor array,the Zurich MFLI lock-in amplifier is used as the signal excitation and acquisition circuit,and the 32 channel network electromagnetic relay is used as the channel switching module to build a hardware system for the electromagnetic tomography experiment,which lays the foundation for the next step of the remote experimental platform.(3)The remote experimental platform of electromagnetic tomography is built,which including website development,the research and implementation of online monitoring and remote control of experimental equipment.Specifically,build the website by Python's Flask framework which has the function of registration,login,upload experimental data and online image reconstruction,then realize the real-time monitoring on the website using Hikvision webcam and RTSP protocol,finally,the remote control unit are embedded into the website using Matlab toolbox web app server,which realize the real-time monitoring and remote control of the electromagnetic tomography experiment.So the experimental operation and the experimental equipment are separated,and the whole system of the remote experimental platform of electromagnetic tomography is completed.