Study On Three-dimensional Surface Topography Based On White Light Interferometer

Three-dimensional microscopic surface topography detection is an important method to obtain surface morphological features.Compared with the traditional contact method with low measurement efficiency,the non-contact white light interferometry method has many advantages and is an ideal method for measuring microscopic surface morphology.However,the single measurement range can not meet the measurement needs,this paper proposes to obtain a more complete microscopic surface morphology based on the overlapping area gray image mosaic technology.Unlike one-dimensional and two-dimensional data,the three-dimensional data is closer to the reality,which can better describe the microscopic surface morphology.At present,the surface morphological feature analysis in the continuous improvement of the three-dimensional assessment method,compared to the previous two-dimensional assessment method is more global,can more comprehensively reflect the microscopic surface morphology.In this paper,the fractal Characterization,power spectrum analysis and three-dimensional parameter characterization of microscopic surface topography are studied.The main research work has the following points:(1)Analyzing the microscopic surface measurement method,discussing the measuring principle of white light interferometer and the composition of software and hardware,and introducing the related measurement process.(2)Based on the traditional feature detection and matching algorithm research,a set of white-light interferometer can be used in the gray image mosaic algorithm flow.In the process of image matching,SURF,ORB and Harris Corner Point detection are used respectively,the experiment shows that the ORB algorithm can be well applied to the research of the subject.Then using the Euclidean distance culling error matching point,combined with the multi-pixel fusion algorithm,the seam is stitched to achieve the image stitching effect.(3)The three-dimensional topography visualization is realized by analyzing the microscopic surface topography height data collected.The point cloud stitching is realized by mapping the two-dimensional feature points in image stitching to the three-dimensional point cloud data method.By using fractal dimension to study the overall complexity of microscopic morphology,the differential box-dimension method is used to calculate the fractal dimension and to judge the complexity of the microscopic surface with similar roughness.The texture and orientation characteristics of microscopic surface topography were analyzed by using power spectral density method.Given the representation parameters and expressions with different physical meanings,a relatively perfect parameter characterization system is established.(4)Based on MATLAB and Visual C + +,the software architecture and workflow are explained,and the analysis software of three-dimensional microscopic surface topography is developed,which realizes the work of enlarging the field of measurement and microscopic surface morphology.