Research On The Method Of Material Identification Of Ultra Wideband Phased Array

Material identification and quality appraisal are important issues in the field of qualitytesting of industrial materials. The material identification of objects composed of a variety ofmaterials need identify the category of each material first, to conclude the composition andquality of the whole material. Meanwhile, as the fast development of industrial automation,the study of mechanical testing with high speed and high accuracy is urgent. Currently,existing material identification methods still can’t realize identifying the material of eachlayer effectively, besides,the accuracy the methods need to be improved, as the parametersthat affect the material reflection information fail to be considered completely.UWB signal carries the rich band information of the echo signal, and have very hightime resolution and range resolution, which can provide sufficient information of the relationof the reflectance and frequency to realize the material identification and to achieve theprecise identification of a measuring point in the target material. On the other hand,phasedarray technology can achieve beam deflection and beam focusing, father more, the point andthe shape of the beam can change flexible,so it has commonly be used in the field of industrialinspection. The technology enables scanning to cover the parts to be tested of the targetmaterial comprehensively, and realize the comprehensive recognition of the target material inany depth and position.Therefore, to solve the problems of the existing material identification method, this paperpropose a new method for material identification using the advantages of UWB and phasedarray technology in material identification.The main work includes:1. Derive theoretical reflectance curves,which describes the relationship between theinherent material properties parameters and material reflection.The method first research howthe inherent material properties parameters impact the material properties, then deduced thetheoretical reflectance curves, which describes the relationship between the inherent materialproperties parameters and material reflection.This curve is a function about reflectioncoefficient varying with the frequency function, and the parameters in the function is thematerial electromagnetic parameter of each level and the thickness of each level target.Themethod also consider the loss of signal during propagation into the theoretical reflectancecurves.2. Realizing material identification through processing the echo signals to obtain themetrical reflectance curves, and solved the inherent properties of each layer of the target material making use of the metrical reflectance curve and the theoretical reflectance curvestogether.The method uses UWB phased array technology to transmit focusing beam towardsthe target material point-by-point, and then make the receiving UWB echo signalsbeamforming.Rich frequency information containing material properties of the echo signalthen is gained. By signal processing techniques,each metrical reflectance curve can be gotfrom the echo signals.Finally,based on the equivalence relation of the metrical reflectancecurves and the theoretical reflectance curves, using the theory of the minimum value of thecost function, the electromagnetic parameters of each layer of the multilayer materials targetcan be solved, in order to determine the category of each layer of material.