A Metal Surface Roughness Evaluation System Based On The Three Dimensional Reconstruction Technology Of Digital Image

Surface roughness is an important indicator for surface quality, and the surface roughness of metal materials severely affects the appearance quality and properties. Therefore, the reasonable evaluation of metal material surface roughness is very important。At present, most of the methods or instruments for evaluating the surface roughness of metallic materials have the following defects: slow speed, high cost, low accuracy, poor stability, etc.They seldom realize online detection under low environmental requirements, most of them still remain in the stage of two dimensional measurement,the results of the measurement are one-sided, and can’t reflect the overall characteristics of the surface, and can not analyze the surface quality completely.The technology of evaluating the metal surface roughness has been studied in this thesis, and the software which can effectively break the shortage of the existing method has been designed. First, from the gray difference informationa of a two-dimensional metal surface digital image, extract the height difference information between the surface layer, the mapping relationship between the two models is established, and the corresponding method and algorithm of the 3D surface reconstruction of the surface are established. Based on this, the main assessment parameters are selected and the main assessment method and algorithm of surface roughness are established by observing the 3D space model; finally, the experimental tests of the system were carried out by using the rough mill and the smooth milling sample, the measured data and the roughness of the sample standard parameters were compared, the results meet the accuracy of the metal surface measurement, the average error rate of the parameters are not more than 10-1μ m,the feasibility and accuracy of the system are proved.The software is designed on MATLAB platform,its powerful scientific computing function provides a strong guarantee for the high accuracy and fast determination of surface roughness; outside its GUI technology makes the software have good interactivity, user-friendly operation. This system has a wide range of applications, from qualitative analysis of metal workpiece to scientific research institute, it can be widely used in college and professional teaching,it can further develop APP application in handset and other handheld terminals, the inspection of the surface roughness will become more convenient.