Investigation of the structure function for analysis of optically measured surface data (Structure Function II)

为了表征表面，通常使用诸如粗糙度数Ra或Sa的参数。然而，这些以前使用的参数通常不能描述所需应用所需的表面特性。利用结构函数，提出了一种新的表面计量分析方法。然而，结构函数关于表面性质的信息值比上述特征的信息值大得多，因为在所有方向上评估了数据集中所有可能距离的所有高度差。结构函数可以有效地处理光学测量技术中通常出现的大量数据。与其他统计方法相比，结构函数也具有几个优点，例如自相关函数。相比之下，结构函数要实用得多。事实证明，对表面相对粗糙度更高的敏感性是最重要的优势之一。与基于傅立叶的方法相比，该方法更直观地更容易评估，并且与曲面几何形状的变化相比，它更加稳健。它可以应用于表面的任何孔径或几何形状，也可以比较不同测量方法的数据。在以前的项目中，结构函数与粗糙度和波纹之间的关系可以通过相应的模拟来显示。在金刚石车削表面上，实验表明，通过比较结构功能评估，可以快速、轻松地确定轮廓或整个表面上几纳米级的粗糙度差异。由于结构函数适用于表征非常小的粗糙度，它也可用于精确评估几乎任何类型的工具(冲压、成形、拉深工具)的磨损，仅举一个使用的例子。在本续篇建议中，从结构函数推导可靠的参数(描述符)将从理论和实验中进行研究。如上所述，诸如来自轮廓数据的粗糙度参数Ra、Rq或Rz或来自表面数据的Sa或Sq的常规参数不一定是用于质量保证的有意义的参数。因此，在该项目中，独立的描述符将从结构函数中得到，利用该结构函数，通常在新定义方向上的表面表征可以被有意义地扩展。对于波纹度的表征，需要研究非周期或各向异性分布。最后，必须确定用什么下限表面结构，如粗糙度或波纹度，可以绝对表征。另一个目的是证明结构功能也适用于质量控制的损伤指示。

To characterize surfaces, parameters such as the roughness numbers Ra or Sa are conventionally used. However, these previously used parameters often do not describe the surface properties required for the desired applications. With the structure function, we introduce a new analysis method for surface metrology. However, the informative value of the structure function with respect to the nature of a surface is much greater than that of the above-mentioned characteristics, since all height differences are evaluated for all possible distances within the data set in all directions. The structure function can process large volumes of data, which typically occur in optical measurement techniques, efficiently. The structure function also has several advantages over other statistical methods, such as e.g. the autocorrelation function. In contrast, the structure function is much more practicable. The greater sensitivity for comparative roughness on surfaces has proven to be one of the most important advantages. It is intuitively easier to evaluate and, compared to Fourier-based methods, is much more robust compared to variations in surface geometry. It can be applied to almost any aperture or geometry of the surface and allows the comparison of data from different measurement methods as well.In the previous project, correlations between the structure function and roughness as well as ripples could be shown with corresponding simulations. On diamond-turned surfaces, it has been shown experimentally that roughness differences of a few nanometers on profiles or entire surfaces can be quickly and easily determined by comparing structural function evaluations. Since the structure function is suitable for the characterization of very small roughness, it can also be used for the precise assessment of the wear of tools (stamping, forming, deep-drawing tools) of almost any kind, to name only one example of use.In this continuation proposal, the derivation of reliable parameters (descriptors) from the structure function is to be investigated theoretically and experimentally. As indicated above, conventional parameters such as roughness parameters Ra, Rq or Rz from profile data or Sa or Sq from surface data are not necessarily meaningful parameters for quality assurance. In the project, therefore, independent descriptors are to be derived from the structural function with which the usual surface characterization in the direction of new definitions can be meaningfully extended. For the characterization of waviness, a study of aperiodic or anisotropic distributions is required. Finally, it must be determined with which lower limit surface structures such as roughness or waviness can be absolutely characterized. Another goal is to prove that the structure function is also suitable for damage indication for quality control.