Wear Debris Shape Analysis And 3D Reconstruction

The ferrography is a fault diagnosis method based on the analysis of wear particle. In the ferrography, wear particle images reflect the important information of the spare part wearing and tearing within the mechanical equipment. The recognition of the wear particle is the core step of the ferrography. The result of the recognition has direct relation to the correctness of the wear condition monitoring for the equipments. As the composition of the wear debris is the same to the composition of the wear part, an appropriate judgment of the wear debris composition would allow a right definition of the source of the wear particle generation and provide valuable information to the maintain of machinery. The primary component analysis was applied to the wear particle HSI color parameters to judge the composition of the wear debris.Wear debris analysis is restricted to the 2-D shape analysis, because of the limitation of the cost and capability of the 3-D imaging equipment. 3-D analysis is used in some special case. As the depth of field of optical microscope is limited, the sum-modified-Laplacian (SML) operator is used as the image focusing evaluation function. Then the wear debris surface altitude is measured. The image pixels correspond to the focus altitude are segmented from the image and a full depth image is formed. Then the surface altitude information and the full depth surface image is fused together to reconstruct the 3-D surface of wear debris. For real time reconstruction, a quick reconstruction arithmetic is provided. For the reconstruction of the 3-D shape, a change was applied to the optical microscope to get an appropriate equipment to measure the 3-D shape of wear debris. A debris analysis and surface reconstruction software was designed on the Visual C++.net platform.The main contents of the thesis are as follows:1. The development and up-to-date status of wear particle analysis technology and 3-D measure technology at home and abroad are evaluated synthetically. Thestudy plan and main content are presented.2. Principal component analysis is applied to the analysis of wear debris HSI color parameters, and a method to determine the composition of wear debris is found.3. The use of image processing in ferrography image analysis and the theory of 3-D measurement and its use in wear debris measurement is discussed.4. A 3-D shape measurement set is designed using DSP, step-motor, optical microscope, CCD camera and computer, and used on measure 3-D shape of debris5. Software on Visual C++.net is brought forward to analyze debris and reconstruct the 3-D shape of wear debris. The 3-D shape of a wear debris is rebuild using the set mentioned above to collect the 2-D image serial and reconstruct the 3-D shape.