Method for measuring surface roughness based on wavelet Brownian motion texture fusion model

Abstract

The invention belongs to the technical field of surface roughness detection, and particularly relates to a method for measuring surface roughness based on a wavelet Brownian motion texture fusion model, which comprises the following steps: (1) acquiring a laser speckle image; (2) determining an optimal wavelet basis function; (3) determining an optimal wavelet decomposition layer number; (4) carrying out two-dimensional wavelet decomposition on the obtained laser speckle image; (5) performing modeling analysis by using a wavelet Brownian motion texture fusion method to obtain a mathematical model; and (6) substituting the surface texture characteristic parameters of the to-be-measured workpiece into the mathematical model obtained in the step (5), and calculating to obtain the surface roughness of the to-be-measured workpiece. According to the method, a mathematical model between laser speckle image texture characteristic parameters and characterization surface roughness parameters isestablished by using a wavelet and Brownian motion texture fusion method in the aspects of practice and theory, so that the surface roughness of the to-be-measured workpiece can be measured in an online, rapid and non-contact manner through a single laser speckle image.

Description

technical field [0001] The invention belongs to the technical field of surface roughness detection, in particular to a method for measuring surface roughness based on a wavelet Brownian motion texture fusion model. Background technique [0002] Surface roughness refers to the small spacing and unevenness of small peaks and valleys on the processed surface, which belongs to microscopic geometric shape errors. High-tech industries such as national defense and aerospace have stricter requirements on them, which directly or indirectly affect the efficiency of processing and production as well as the performance and life of instruments. [0003] At present, surface roughness measurement methods mainly include contact stylus measurement methods and optical non-contact measurement methods. The non-contact measurement method has been developed and applied rapidly because it will not damage the surface to be measured, and the optical detection method has developed particularly rapid...

AI Technical Summary

Problems solved by technology

Among them, the optical probe method is easily affected by external interference, and the measurement efficiency is low; the laser interferometry technology is complicated, and the adjustment time of the optical system is long; the measurement accuracy of the laser scattering method is not high, the measurement range is narrow, and there is a certain deviation between theoretical calculation and actual measurement results; The laser speckle method has high measurement accuracy, but the speckle contrast method has a small measurement range and is only applicable to R a <0.3μm surface; speckle correlation method usually requires two images to achieve, sensitive to eccentricity and vibration, not suitable for online measurement

It can be seen that online and non-contact measurement of surface roughness cannot be realized

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