Study On Modeling And Compensation Of Eddy Current Sensor And Its Electromagnetic Field Simulation Study

The welding defects of ship are important hidden dangers in safe navigation. Eddycurrent sensor can accurately detect the weld cracking to assess and analysis based onmeasurement results, to ensure the reliability of safe navigation of ships. The detectionperformance of eddy current sensor has a crucial impact on test results, so it has importantpractical significance to analyze and study detection performance of eddy current sensor.Starting from working principle of eddy current sensor, conducting study frommodeling and compensation of static and dynamic and eddy current electromagnetic finiteelement simulation analysis of eddy current sensor aiming at how to effectively improvedetection performance of eddy current sensor. Related work including:1) In order to get actual static and dynamic characteristic of the eddy current sensor,using BP neural network and function link neural network respectively to establish staticmodel of the eddy current sensor, using RBF neural network, LS-SVM and GA-LS-SVMrespectively to establish dynamic model of the eddy current sensor, analyzing andcomparing modeling effect of different methods, choose appropriate modeling methodaccording to different requirement.2) Analyze static and dynamic characteristic based on static and dynamic model. Forobvious nonlinear in static model, adopt the method of concatenated compensation linkbehind sensor to carry on non-linear compensation, the compensation part is the inversemodel of sensor, which is made by BP neural network and function link neural network,both of them achieved good compensation effect; To further improve dynamic characteristicof sensor, adopt lead compensation and inverse neural network(RBF neural network andLS-SVM) to realize dynamic compensation of sensor, compare advantages anddisadvantages of different methods.3) Based on Ansoft Maxwell to establish finite element simulation model of eddycurrent sensor, analyze influence factors in the process of testing, extract different axiscomponent of magnetic field when defect exists, and analyze the characteristic quantities tofind that length, depth and buried depth of defect and the coordinate axis characteristicamount have corresponding relation, based on this can be judged is surface defect or internaldefect, it provided valuable reference for quantitative analysis of defects and classificationof defects.The thesis is complete the prototype development of eddy current testing system, carried out preliminary research work especially in terms of its data processing andsimulation analysis. Because of the tight schedule and heavy task, relative reseach work hasmany places to improve further and deeper, the focus of future work has been described andsupplemented in the conclusion part of paper.