Analysis Of Surface Roughness Measurement And Evaluation Method Based On Differential Confocal Microscopy Imaging System

Surface roughness is an important part of surface quality evaluation and has important applications in mechanical,electronic,biomedical and optical fields.With the progress and development of nanotechnology,micro-machining and ultra-precision machining technology,the surface size of parts is becoming smaller and smaller,and the measurement technology of surface roughness is becoming more and more demanding.At the same time,because 3D surface topography can better reflect the true characteristics of machined surface,the evaluation of surface roughness is developing towards 3D evaluation,so it is more and more important to analyze the measurement and evaluation methods of surface roughness.In this paper,using differential confocal microscopic imaging principle,the surface morphology of machined surface is measured by non-contact and high-precision measurement.The surface roughness evaluation method and evaluation parameters are deeply studied to realize the two-dimensional machined surface.The parameter evaluation of 3D surface roughness meets the requirement of measuring and evaluating the surface roughness.The research content of this project comes from the project "in situ imaging method and technique of high scattering laser differential confocal microscopy Raman spectroscopy" funded by the National Natural Science Foundation of China.The project number is 61475020.The main contents of this paper are as follows:(1)Evaluation of two-dimensional surface roughness.The evaluation datum line is established by using Gao Si filter,and the shape error curve,corrugation curve and roughness curve are separated.By studying the existing surface roughness evaluation parameters,13 two-dimensional surface roughness evaluation parameters and their calculation formulas are given.The evaluation of shape error,corrugation and roughness is realized.(2)Three dimensional surface roughness evaluation.By analyzing the two-dimensional Gao Si filter,it can be divided into two-order one-dimensional filter to improve the processing speed.The evaluation datum is established by using two-dimensional Gao Si filter,and the shape error surface,corrugation surface and roughness surface are separated.The amplitude parameters and function parameters are given by studying the evaluation parameters of the existing 3D surface roughness.There are 17 concrete three dimensional surface roughness evaluation parameters and their calculation formulas in three categories of volume parameters to realize the parameter evaluation of three dimensional surface roughness.(3)By using the software of VS2010,the surface roughness function module is programmed and tested,and the surface roughness module interface is designed to realize the automatic measurement and evaluation of the roughness of the machined surface.(4)The algorithm program is written by MATLAB and compared with the existing commercial confocal microscope under the same set of measurement data to verify the accuracy of the roughness evaluation method and the evaluation parameters.The surface morphology and roughness of standard samples were measured by differential confocal microscopy and compared with commercial confocal microscopy to verify the accuracy of the whole measurement system.