Calculation Of Roughness Parameters Research Articles

Surfalize: A Python Library for Surface Topography and Roughness Analysis Designed for Periodic Surface Structures.

Surface roughness measurement is an integral part of the characterization of microtextured surfaces. Multiple established software packages offer the calculation of roughness parameters according to ISO 25178. However, these packages lack a specific set of features, which we hope to address in this work. Firstly, they often lack or have limited capabilities for automated and batch analysis, making it hard to integrate into other applications. Secondly, they are often proprietary and therefore restrict access to some potential users. Lastly, they lack some capabilities when it comes to the analysis of periodic microtextured surfaces. Namely, common parameters such as the peak-to-valley depth, spatial period and homogeneity cannot be calculated automatically. This work aims to address these challenges by introducing a novel Python library, Surfalize, which intends to fill in the gaps regarding this functionality. The functionality is described and the algorithms are validated against established software packages or manual measurements.

Acceleration of surface roughness evaluation using RANSAC and least squares method for Running-in wear process analysis of plateau surface

ISO 21920–2 defines an analysis method and the roughness parameters needed for evaluating the roughness of plateau structure surfaces. The roughness parameters are calculated by fitting straight lines to a material ratio curve. The analysis method by ISO 21920–2 cannot calculate the roughness parameters of surfaces with insufficient plateau structure. In previous studies, analysis methods that enable the calculation of roughness parameters for surfaces with insufficient plateau structure were proposed. However, these analysis methods have the problem that the algorithms do not achieve both automation and speed-up of the plateau surface analysis. Therefore, in order to solve this problem, we propose a new method called “Straight Lines Fitting using RANSAC and Least Squares Method (RLF method)”. RLF method enables the automatic and more than 100 times faster calculation of roughness parameters for surfaces with insufficient plateau structure. RLF method is expected to contribute to improvements in productivity at production sites.

A Novel Light Sectioning Vision System for A Three Dimensional Surface Roughness Assessment (Dept.M)

Standard roughness measurement procedures depend heavily on stylus instruments which have only limited flexibility in handling different parts. On the other hand, optical non-contact techniques are very interesting for 3D characterization of sensitive and complex engineering surfaces. In this study, a new ap proach is introduced to measure surface roughness in three dimensions by combining a light sectioning microscope and a computer vision system. This approach has the advantages of being non-contact, fast and cheap. A prototype version of a user interface program, currently named SR3D Vision, has been developed to manage three dimensional surface roughness measurements. A light sectioning microscope is used to view roughness profiles of the specimens to be Measured and the vision system is used to capture images for successive profiles. This program has been totally developed in-house using MatlabTM software to analyze the captured images through four main modules: (Measurement controller, Profile or surface extraction, 2D roughness parameters calculation and 3D roughness parameters calculation). The system has been calibrated for metric units and verified using standard specimens. In addition, the system was used to measure various samples machined by different operations and the results were compared with a commercial software and a web-based surface metrology algorithm testing system. The accuracy of the system was verified and proved to be within ±4.8% compared with these systems.

Calculation of Roughness Parameters during Ultrasonic Hobbing from the Viewpoint of the Theory of Elastic-Plastic Contact

This article analyses the process of occurrence of the surface roughness during the ultrasonic hobbing of the fine pitch gears from the viewpoint of the theory of elastic-plastic contact, and suggests analytical solutions and regression equations to estimate the roughness parameter Ra in both conventional and ultrasonic machining.

Some Considerations about the Use of Contact and Confocal Microscopy Methods in Surface Texture Measurement.

Surface metrology employs various measurement techniques, among which there has been an increase of noteworthy research into non-contact optical and contact stylus methods. However, some deeper considerations about their differentiation and compatibility are still lacking and necessary. This work compares the measurement characteristics of the confocal microscope with the portable stylus profilometer instrumentation, from a metrological point of view (measurement precision and accuracy, and complexity of algorithms for data processing) and an operational view (measuring ranges, measurement speed, environmental and operational requirements, and cost). Mathematical models and algorithms for roughness parameters calculation and their associated uncertainties evaluation are developed and validated. The experimental results demonstrate that the stylus profilometer presents the most reliable measurement with the highest measurement speed and the least complex algorithms, while the image confocal method takes advantage of higher vertical and horizontal resolution when compared with the employed stylus profilometer.

Calculation Possibilities of 3D Parameters for Surfaces with Irregular Roughness

Abstract In the scientific research, calculations of roughness parameters are carried out, with the aim of comparing measured values of roughness parameters with the calculated ones by normal random field equations. First of all, roughness measurement experiments for surfaces with irregular roughness are carried out to determine the roughness parameters and the ordinate distribution histograms using modern measuring equipment Taylor Hobson Talysurf Intra 50. Using the obtained experimental data, Pearson criterion calculations are made in order to check the compliance of surface ordinate distribution function to normal Gaussian distribution law. The obtained results showed that for all investigated samples the surface ordinate distribution function complies with normal Gaussian distribution law. The next step is the calculation of several 3D roughness parameters (from the standard ISO 25178-2). According to the obtained results it is concluded that the calculated values of surface roughness parameters Sa, Sp, Spc, Sdq, Sdr are quite close to the values obtained by measuring equipment Taylor Hobson. The acquired formulas may be applicable for determination of 3D roughness parameters.

Measurement default diagnostics of a roughness meter with TS100 head using a rectified specimen and solved by fuzzy logic estimator

The purpose of this study is to diagnose defaults of the TR200-roughness meter by contact measurement using the same path with two opposite directions of the probe left and right. We conducted a series of tests on the same rectified part with a roughness of 0.553 μm using a roughness meter equipped with a TS100 standard probe at a probing path of 8.5 mm, a drive speed of 0.5 mm/s and a feedback speed of 1 mm/s. The originality of this present work focuses on the measurement default diagnosis of the roughness of the surface from the change in direction of the probe after each measure in the same trajectory. This approach validates the unreliability of a roughness meter in the case of parts machined by cutting processes (turning, milling, and grinding). These tests have enabled us to limit the control of the surface state by a TS100 standard probe. For each test, a disagreement was found between the right and left directions by making the calculation of roughness parameters. Estimator fuzzy logic was implemented to solve this problem, obtaining satisfactory results with minus proportional errors between the actual displacement curve and the curve displacement obtained by this system.

Surface fitting of an involute spur gear tooth flank roughness measurement to its nominal shape

Abstract A method for fitting a topography measured on an involute spur gear tooth flank to its nominal shape is proposed, so that the exact position along the length of the tooth from which the measured surface originates can be determined, and so that the nominal shape of the surface can be subtracted prior to roughness parameters calculation.

Multiscale similarity characterization of abraded surfaces

Many surface properties are related to their topography. The characteristics of an engineering surface can be recorded as a roughness profile characterized by calculation of roughness parameters. The supposed relevant parameters are used to characterize the surface and to tailor similar surfaces with the same characteristics. The aim of this paper is to propose an alternative method based on information theory to avoid roughness parameters calculation in quantifying the similarity of two roughness profiles. The relevance of this method is emphasized using experimental profiles.

Measurement of surface roughness on rough machined surfaces using spectral speckle correlation and image analysis

A speckle pattern is formed when a rough surface is illuminated with coherent light. The properties of this pattern can be used in the calculation of roughness parameters. Spectral speckle correlation (SSC) is a technique applicable to the measurement of roughness on rough machined surfaces. This paper presents the SSC obtained from measurements on specimens with a surface roughness in range R a = 0.5–5 μm. The measurement results correspond to reference measurements made using a stylus instrument, Form Talysurf.