Research On Automatic Leveling And 3D Reconstruction Method Of White Light Scanning Interferometry System

White light scanning interferometry is an important 3D surface topography measurement technology.Due to its non-contact,surface scanning,high accuracy,and no phase blur,it has been widely used in the field of microscopic surface precision measurement.At present,how to improve the degree of automation,accuracy and speed of measurement is still the key issues of this technology.This paper mainly focuses on these issues.Based on the flexible hinge angle adjustment platform,an automatic leveling algorithm is proposed to solve the problems of tedious operation and low efficiency in the manual leveling process.At the same time,a 3D surface reconstruction algorithm based on fast template matching is proposed to maintain the balance between measurement speed and measurement accuracy,and achieve high-speed,high-precision3 D surface reconstruction.The main research contents of this paper include the following:1.Systematically investigate the current research status of the existing ultra-precision three-dimensional surface topography measurement technology,analyze and compare the basic principles,advantages and disadvantages of related technologies,and clarify the key problems of the current white light scanning interferometry technology.2.Deeply study the characteristics of white light interference and the principle of white light scanning interference measurement system,design the overall structure of the measurement device according to its principle,select the required relevant parts,and finally build a set of white light interference measurement experiment device,and analyze the main performance parameters of the system.3.Aiming at the problem of low accuracy and low efficiency caused by manual observation of fringe and manual leveling in the process of white light interference measurement,the automatic leveling method is studied in depth,the principle of automatic leveling based on fringe image feedback is proposed.Combining with theflexible hinge angle adjustment platform,a stepping leveling algorithm based on the flexible hinge angle adjustment platform is proposed to effectively realize the automatic leveling of the measurement system,and the algorithm is verified through experiments..4.Aiming at the shortcomings of the existing algorithms in the measurement accuracy or measurement speed,according to the same or similar characteristics of the white light interferometry signal,a 3D reconstruction algorithm of white light interference based on fast template matching is proposed,which fast locates the position of zero optical path difference through coarse and fine steps to reconstruct the 3D topography.The algorithm combines the rapidity of the centroid method and the accuracy of template matching to achieve high-precision measurement while ensuring a faster measurement speed.Finally,simulations and experiments verify the effectiveness of the proposed algorithm.5.Through programming to realize the above-mentioned related algorithms,a 3D measurement software for white light scanning interference was developed..The measurement system has the functions of motion control,image acquisition,automatic leveling,3d reconstruction and result display,and the 3D reconstruction data is filtered and de-noised to improve the measurement accuracy of the system.Finally,the effectiveness of the white light interference measurement system is verified by experimental test.