表面形貌评定的B样条小波基准线的实现

Realization of B-spline wavelet reference line for the surface topography evaluation

随着科学技术的发展,对工件的表面精度提出了更高的要求。表面形貌特征在很大程度上影响了工件的技术性能和使用功能。近年来,国内外对表面形貌特征进行了大量的研究,制定了相关的标准。但是仍然存在一些不确定性和模糊性。文中针对高斯滤波器存在边界效应和对缺陷表面产生形变的不足,提出了一种B样条小波获取表面形貌功能评定基准线的方法。首先建立表面形貌的数学模型,采用小波分析的分解与重构原理,实现了表面形貌的数学模型的小波构建。最后根据小波变换的定义,用B样条函数构造出B样条小波函数,并将其应用于表面形貌的分析,从而实现了表面轮廓与基准线的分离。通过实例对比分析,该方法要优于高斯滤波获取基准线的方法。B样条小波分离法不仅消除了边界效应,而且消除了表面异常值高斯基准线的变形。

The higher accuracy for workpiece was required in surface measurement with the technology development. The surface topography characteristics affect greatly the technical features and functions of workpiece. In recent years, though many researches have been made on the surface topography and related standards have been presented, the end effects and surface distorts still exist in these standards. This paper aims at the end effects and surfaces of Gaussian Filter, a new method using B-spline wavelet to evaluatethe surface topography parameter is proposed. First, we established the mathematical model of the surface topography. The mathematical model of surface topography was realized by using the decomposition and reconstruction of orthogonal spline wavelet. According to the definition of the wavelet, we use B-spline function to generate B-spline wavelet function. We realized the different frequency components separation by this method. The experimental results show that this method is better than Gaussian Filtering. B-spline wavelet analysis not only eliminates the end effect, but also eliminates deformation of the reference line because of the abnormal characteristic.