三维粗糙表面的计算机生成及其纹理控制

工程实际中,大部分机械加工后的表面都存在一定的纹理,纹理作为表面的一种空间特征,无法用单一的表面形貌参数来描述其各向异性特征。利用基于AR模型的二维数字滤波技术,通过计算机模拟生成具有指定自相关函数的粗糙表面;通过控制自相关函数来控制纹理,获得纹理的本质特征,在此基础上提出了一种能有效模拟所需表面纹理的自相关函数。结果表明:数字滤波的方法能比较准确地生成具有规定自相关函数的表面;表面纹理与自相关函数的周期分量相关,可通过控制自相关函数的周期特征来模拟具有周期性的加工表面纹理。最后通过与WYKO实测的表面对比以及由实测表面来获得自相关函数的图像对比,证实方法的有效性。

The Generation of Three Dimensional Rough Surface and the Control of Texture Feature

In engineering,almost all machined surfaces have some sorts of texture features.As a spatial feature,texture can hardly be described by a single parameter of surface topography.Based on the autoregressive(AR) model,the technology of digital filter was used to generate the rough surfaces that have the given autocorrelation function(ACF).To generate the rough surfaces according to the specified ACF,and control the texture by a properly designed ACF,a new form of ACF that can create desired texture most effectively was proposed.The results indicated that the method of digital filter can be used to generate the rough surfaces that have the given ACF accurately.There is an obvious relativity between the surface texture and the periodic component of the ACF.By controlling the periodic character of the specified ACF,the rough surfaces that have the periodic texture can be generated.The comparisons between the computer generated surfaces and the engineering surfaces measured by the WYKO,and their ACF as well,provide a validation for the proposed method.