Research On Method Of 3D Surface Roughness Measuring Based On Multi-Sequence Images

The matching up and working performances of machining part, especially as wear resisting property, lubricating ability and fatigue resistance, are significantly affected by the surface roughness. So it's very important to evaluate reasonably surface roughness. Higher machining precision and service performance are required along with the developing of industry, so more accurate and comprehensive measurement and evaluation surface roughness in 3-D is needed urgently.The main content of this thesis is measurement of the workpiece surface roughness used one-eye microscope combined with computer image processing technology, thereby non-contact method of measurement of roughness was studied. Complete and clear information on the object surface can't be obtained from one image because of the limitation of the microscopic focal length. A sequence of object images can obtain by moving the object in the Z axial and scanning the object surface layers through microscope. At the same time the initial value of Z-axis of each image was also obtained; then the focus area in every image was picked-up and fused them in an all-focus image. On the other hand, clear portion of each image of the sequence of images was calculated by focus measure operator, height value of each point was calculated by Gaussian interpolating to the results of focus measuring, using high-level information to reconstruct 3-D surface of the microscopic samples.3-D model of micro-samples was simulated. Finally, a set of elevation data collected using microscope was analyzed by handwriting software to acquire a set of 2-D and 3-D roughness parameters and 3-D evaluation curve.Through the results obtained was analyzed, the 3-D parameters of rationality and effectiveness were confirmed. The feasibility of 3-D detection of surface roughness based on digital imaging technology was approved. The experimental work has laid a foundation for establishing scientific standard of 3-D detection of surface roughness and developing relevant testing system in the future, which has significant meaning for realizing on-line measurement and completely obtaining 3-D data.