Methods and systems for measuring and classifying the cleanliness level of surfaces after high-power laser cleaning

Abstract

The invention relates to a method and system for measuring and classifying the cleanliness level of a surface cleaned by a high-power laser, comprising the following main components: a sealed chamber (1), a moving table (2), a measuring sample (3), a camera (4), an LED lighting system (5), and a computer (6). The moving table (2) assists in adjusting the position of the measuring sample (3) to ensure that the measurement area is within the convergence area of ​​the camera (4). The camera captures the surface image with the support of an LED lighting system whose illumination intensity is adjusted to 420 lumens to ensure appropriate contrast between the background and the stain. The image data is transmitted to a computer (6) for processing by measuring and classifying the cleanliness level of the surface after cleaning with a high-power laser (S101-SI07). This method uses sample images according to the ISO BS EN ISO 8501-1:2007 / SIS 055900 surface standard to establish a cleanliness level (S101), converts the original image to grayscale (SI02), determines the brightness threshold for classifying dark pixels (SI04-SI05), and calculates the ratio of dark pixels to the total number of pixels (SI06). The evaluation scale is established based on the ratio of dark pixels, with SA3 having a ratio below 3%, SA2 from 3% to 10%, SA2 from 10% to 45%, and SAI above 45%. These results allow for the precise determination of the surface cleanliness level after cleaning (SI 07).