Suppression of the High-Frequency Errors in Surface Topography Measurements Based on Comparison of Various Spline Filtering Methods

Abstract

The metrology of so-called “engineering surfaces” is burdened with a substantial risk of both measurement and data analysis errors. One of the most encouraging issues is the definition of frequency-defined measurement errors. This paper proposes a new method for the suppression and reduction of high-frequency measurement errors from the surface topography data. This technique is based on comparisons of alternative types of noise detection procedures with the examination of profile (2D) or surface (3D) details for both measured and modelled surface topography data. In this paper, the results of applying various spline filters used for suppressions of measurement noise were compared with regard to several kinds of surface textures. For the purpose of the article, the influence of proposed approaches on the values of surface topography parameters (from ISO 25178 for areal and ISO 4287 for profile standards) was also performed. The effect of the distribution of some features of surface texture on the results of suppressions of high-frequency measurement noise was also closely studied. Therefore, the surface topography analysis with Power Spectral Density, Autocorrelation Function, and novel approaches based on the spline modifications or studies of the shape of an Autocorrelation Function was presented.

Selection of Methods of Surface Texture Characterisation for Reduction of the Frequency-Based Errors in the Measurement and Data Analysis Processes

“…When the centre of an ACF was studied alongside profile exploration, the amplitude of a value growth increased more rapidly when high-frequency errors were found. This trend has already been noticed before when an autocorrelation function centre-shape method (ACF-CSM) was developed [26]. For plateau-honed cylinder liners, the TTP can be decisive.…”

“…As mentioned before, the ACF-CSM approach may be valuable, nevertheless, as suggested in previous studies, multi-threaded analysis [26] may be required. When applying a PSD analysis, the regular user must be reserved to use an 'all direction method' in deriving the 3D (areal) PSD performance.…”

“…In this case, the treatment trace technique, based on the profile characterisation, can be additionally applied. This technique was presented widely in a previous paper by the author, defined as a treatment trace profile (TTP) [26] or, a simplifying, treatment direction method (TDM) [31]. This method can, in this case, improve the profile (2D) utility over an areal (3D) when high-frequency measurement noise is detected.…”

“…The high-frequency noise can be caused by the instability of the mechanics with any influences from the environment or by internal electrical noise. Nevertheless, the high-frequency noise, in most cases, is the result of vibration [26].…”

Discharge Energy as a Key Contributing Factor Determining Microgeometry of Aluminum Samples Created by Electrical Discharge Machining

“…This is mainly caused by the fact that that they are included in the widely used commercial software and they can be evaluated with basic knowledge of surface metrology principles. Alternative approaches using multiscale analysis or autocorrelation function are still rare [57,58], because, in principle, they are more complicated and would require more skillful and mindful users. They will be appreciated once they add value by advancing the understanding of the relations between topographies and phenomena or if they can better exploit the acquired topographic information [29,59].…”