Three Dimensional Profile Measurement System Based On Frequency Spectrum Separation And Least Squares Algorithm

With the accumulating and developing of technology in the area of laser technology,software engineering,high precision machinery,automatic robot,more and more creative and accurate measurement technology step into modern science and engineering technology fields which assistants the leap of these fields.Various fields has its different requirement,object and precision in precision measurement.So it is essential that the three-dimensional surface of the measured object applied in various material.Glass is a kind of extremely widely used material,which is suitable in aerospace,biomedical,microelectronics,optics measurement,nanometer technology and other industries.Although wave-number scanning surface measurement method major in composite material measurement,and researcher scholars have breached the bottleneck in this sphere,it is rare that wave-number scanning method applied in measuring the flatness and surface of Glass material.As for this situation,this paper puts forward to use glass slide and lens as experimental samples,analyses the advantage of using Spectrum Decomposition and Least Squares Algorithm in glass material measurement in theory,and confirm the advantage of using this algorithm in experiment basing in the actual experiment data.As in 3D surface measurement system,firstly,CCD camera continuously take N interference images,recorded interference fringes message between optical wedge and glass slide.Then,the random discrete Fourier transform,which transforms interference from time domain to frequent domain,is performed at each pixel on all the time-resolved interfering image sequences and get winding phase message.Finally,it is easy to restore experiment sample actual surface through unwinding phase method.The research work of this paper is mainly as follows:(1)On the basis of the wave number scanning interference measuring instrument,experiment sample use glass slide and the glass lens,and design a three-dimensional surface measuring system which base on the wave number scanning interference.(2)Calibrate the camera and confirm the final calibration result through the actual calibration data.(3)proposing a data demodulation algorithm that aim at solving the problem of spectrum aliasing of interference surface signals.