Three-dimensional reconstruction method for damaged corrosive pitting topography of metal panel

Abstract

The invention discloses a three-dimensional reconstruction method for the damaged corrosive pitting morphology of a metal panel. The three-dimensional reconstruction method comprises the following steps: scanning the corrosion pit surface topography of the metal panel so as to be used as a reference picture; aligning laser emitted by a laser displacement sensor to the top of a corrosion pit, setting the indication of the laser displacement sensor as zero, translating the laser displacement sensor so as to enable the laser to be aligned to the bottom of the corrosion pit, wherein the indication of the sensor is the height difference from the top to bottom of the corrosion pit, and the height difference is the depth of the corrosion pit; and establishing an NURBS (Non-Uniform Rational B-Spline) surface by utilizing the gray scale value of the reference picture, and stretching the NURBS surface into a body, thus completing the reconstruction of the pitting corrosion area topography of a test piece. The three-dimensional reconstruction method is simple and accurate to scan and input; the measurement precision of the laser displacement sensor can achieve 10-3mm which can meet the requirement of the corrosion pit on depth less than 1mm; and the existing commodity software can be adopted for replacing the manual programming, so that the working efficiency is improved.

Description

technical field [0001] The method belongs to the technical field of computer image processing, and in particular relates to a method for reconstructing a three-dimensional shape from a single two-dimensional grayscale image. Background technique [0002] The aluminum alloy sheet metal parts used in the aircraft structure will be corroded by chemical pollutants in the air and pitting corrosion will occur in the atmospheric environment. cause aircraft safety accidents. In order to analyze the structural fracture caused by pitting, it is very necessary to analyze the stress distribution on the surface of the entire pitting area first. However, the surface pitting corrosion morphology of aluminum alloy is complex, and there is no ready-made physical model. At this time, the 3D reconstruction method can be used to establish a 3D model and analyze it. [0003] Existing surface image acquisition technologies mainly include digital camera photography and microscope photography. ...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the disadvantages of large surface area error, large pit depth measurement error, and low efficiency of manually writing computer programs caused by existing photographing techniques, the present invention provides a method for three-dimensional reconstruction of pitting damage morphology of metal plates based on gray values. It can quickly realize the shooting of two-dimensional grayscale pictures of surface corrosion pit topography, and carry out three-dimensional image computer reconstruction of pitting surface topography according to the grayscale value and the depth value measured by the laser displacement sensor

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