In order to solve the problem of accurate measurement of scratches on the surface of airplane cabin and wing skin, a surface scratch measurement system based on digital image processing technology was designed. The measurement system of the aerial scratch detector imprints the scratches on the surface of the object on the CCD, and through the segmentation, transformation, fitting and other processing of the scratch images, the depth of the scratches is finally obtained. Compared with human eye aiming method, this method can reduce human measurement error and improve measurement accuracy and efficiency. By repeated measurement of standard scratch, the difference of test standard can reach 0.5 micron, which can meet the needs of engineering measurement.
Aircraft manufacturers and maintenance companies are paying attention to the possibility that improper construction may leave some scratches on the pressurized fuselage skin. Aviation scratch tester according to the nature of the skin scratch line and mechanical characteristics, using ANSYS software to calculate the maximum stress of scratch gap and the local stress strain estimate the fatigue life of the component under cyclic load, systematic analysis of the different degree of scratch lines on pressurized fuselage skin structure integrity, and some meaningful conclusions are obtained.
The scratch measurement system is designed based on the principle of light cutting to obtain the contour image of the 45° oblique section of the scratch relative to the surface, and obtain the actual scratch depth through image processing. This system mainly includes scratch optical imaging, image acquisition, image processing, mainly used to measure surface scratches, concave and convex, such as aircraft wing skin surface scratches, cockpit scratches and so on.