A quality detection method for flat glass based on the principle of laser continuous wave modulation

Abstract

The invention discloses a flat glass quality detection method based on the principle of laser continuous wave modulation, which includes an image acquisition module, image preprocessing, edge extraction, Gray code image encoding and decoding, and a baseline method for estimating front and back surface points of the flat glass. Collect infrared images and depth data; preprocess the collected images; extract the edge of the measured flat glass; encode and decode the Gray code image to obtain the front surface point of the measured flat glass and the direction of the reference light; Carry out calibration to obtain the light direction of the camera; estimate a certain group of points corresponding to the front and back surfaces of the flat glass according to the baseline method, and obtain the measurement results of the thickness of the flat glass. , and the three-dimensional topography of the reverse side, so that the defects and defect sizes on the front and back surfaces can be measured respectively. The invention can make the results of flat glass thickness measurement and defect size more accurate.

Description

technical field [0001] The invention belongs to the field of product quality detection, and in particular relates to a flat glass quality detection method based on the principle of laser continuous wave modulation. Background technique [0002] The thickness of flat glass is a very important quality indicator in the production process of flat glass. Many plates have high requirements on the flatness, thickness and existence of defects on the plate surface. The shortcomings of measuring tools such as thickness gauges are that there is relative sliding between the flat glass and the measuring tool, which may easily cause scratches on the surface of the flat glass, and manual reading is required, resulting in large errors. In addition, the sensor probe of the contact thickness gauge is also subject to wear and tear, requiring frequent recalibration and regular replacement of the probe. For large-sized plates, laser triangulation and interferometry can be used to achieve non-co...

AI Technical Summary

Problems solved by technology

[0002] The thickness of flat glass is a very important quality indicator in the production process of flat glass. Many plates have high requirements on the flatness, thickness and existence of defects on the plate surface. The disadvantage of measuring tools such as thickness gauges is that there is relative sliding between the flat glass and the measuring tool, which can easily cause scratches on the surface of the flat glass, and requires manual readings, resulting in large errors

In addition, the sensor probe of the contact thickness gauge also has a certain degree of wear and tear, and needs to be recalibrated frequently and the probe should be replaced regularly

For large-sized plates, laser triangulation and interferometry can be used to achieve non-contact measurement, but the actual measurement process is affected by various factors, such as jitter, so that the measurement accuracy will still be greatly affected

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