Based On Gray Level Co-occurrence Matrix Texture Parameters Of The Non-planar Surface Roughness

The technology of machine building is used in manufacturing widely, so the measurement of surface roughness for exact workpiece has to be improved to meet new requirements. The measurement of laser speckle is paid much attention by people for its good advantages without contacting, damaging and so on, and has been applied to manufacture. The existing measurements of laser speckle are used to measure workpieces'surface roughness whose surface are plane, and the research on nonplanar measurement of surface roughness is hardly reported. The most precision workpieces'surface are nonplanar, so it's necessary to do further study on nonplanar measurement of surface roughness.The texture of nonplanar workpieces are different as result of adopting different machining technics, such as thickness, directtion, density and so on, the information of machining exists in those texture, and can be extracted by some methods that analyses the character of texture. The character of image's texture can be reflected by Gray Level Co-occurrence Matrix's four characteristic parameters that are second moment, inertia, corralation and entropy, thus the four texture's parameters can be used to study the nonplanar surface roughness. A experimental setup which is aimed at nonplanar workpiece is designed to obtian laser speckle images by CCD, then digital images and numerical value are processed by MATLAB7.0 software .The three parameters which are the making directionθ, the making step d and the gray-level g of image have an effect on making Gray Level Co-occurrence Matrix (GLCM), and the effect is considered seriously in this paper. Appropriate d and g are selected after theoretic analyse and numerical compare, and a Synthesized GLCM(SGLCM) is designed to calculate numerical value. At last, some curves are ploted that the SGLCM's four characteristic parameters change along with the surface roughness Ra. The experimental results indicate that the four parameters can show nonplanar surface roughness's information, so it can be considered as a new method to study the measrement of nonplanar surface roughness.Finally, a graphical user interface(GUI) is developed by matlab7.0 software, which can be used to calculate the texture's characteristic parameters and ploted the curves that show the connection between surface roughness and characteristic parameters .