数控加工中3D表面形貌数字图像处理技术

3D Surface Topography Analysis Using Image Processing Technology in NC

摘要: 在数控加工中，加工表面的几何形貌特性在很大程度上影响着它的许多技术性能和使用功能。开展对加工表面形貌的研究是表面科学中重要的研究课题之一。研究表明，工程表面具有随机性、无序性、自相似性、自仿射性和多尺度性等分形特性。表面形貌影响光学元件的机械性能、物理性能、成品率；在特定应用场合下，通过检测光学元件表面三维微观形貌来检测光学元件的加工质量。将工件表面置于光学显微镜焦面上观测，如观测到工件表面某处存在明显缺陷，通过光学显微镜上下数次微移动，对工件表面该处采集多幅对焦图像并进行图像处理，根据处理结果判别工件是否符合加工要求。文中提出了一种基于MATLAB2012高级语言编写的图像处理软件，实现对数幅对焦图像进行分析处理进而拟合出表面微观形貌的三维图形。

Abstract: Topography of machined surface affects many of workpiece’s technical performance and function to a large degree in NC machining. Surface topography is one of the important research topics in surface science. Studies show that machined surface has some fractal characteristics such as randomness, disorder, self-similarity, self-affine and multiscale. Surface topography influences the mechanical properties, physical properties and the rate of finished products. Under certain situations, processing quality of optical elements is detected by detecting 3D micro topography of optical surface. The surface of the workpiece is observed by placing on the focal plane of optical microscope. If there are obvious defects on the workpiece surface, several focus images from this workpiece surface are acquired and processed by moving the optical microscope up and down several times. According to the result of image processing, we judge whether a workpiece is conformed to machining requirements. An image processing software based on MATLAB2012 language is proposed in this paper, which achieves processing and analysis for several focus images, then fitting the 3D surface topography.