Non-Contact Surface Roughness Measurement by Implementation of a Spatial Light Modulator

Abstract

The surface structure, especially the roughness, has a significant influence on numerous parameters, such as friction and wear, and therefore estimates the quality of technical systems. In the last decades, a broad variety of surface roughness measurement methods were developed. A destructive measurement procedure or the lack of feasibility of online monitoring are the crucial drawbacks of most of these methods. This article proposes a new non-contact method for measuring the surface roughness that is straightforward to implement and easy to extend to online monitoring processes. The key element is a liquid-crystal-based spatial light modulator, integrated in an interferometric setup. By varying the imprinted phase of the modulator, a correlation between the imprinted phase and the fringe visibility of an interferogram is measured, and the surface roughness can be derived. This paper presents the theoretical approach of the method and first simulation and experimental results for a set of surface roughnesses. The experimental results are compared with values obtained by an atomic force microscope and a stylus profiler.

Fuzzy Clustering Algorithm with Non-Neighborhood Spatial Information for Surface Roughness Measurement Based on the Reflected Aliasing Images

“…The best performance is obtained when the value vpc is maximal or vpe is minimal. Finally, to contrast the performance of different roughness indexes, the coefficient of determination R 2 [9] are adopted:R2=1−true∑false(y−y∗false)2true∑false(y−truey¯false)2 where y is the value measured by stylus, y¯ is the average value of y , and y∗ is the predicted regression value.…”

“…Generally, the measurement techniques of surface roughness can be divided into contact and non-contact methods [9,10]. The most common contact type is the stylus method, which has been used extensively in a lot of systems and performs well [11].…”

Survey of Procedural Methods for Two-Dimensional Texture Generation

“…Tactile sensing and texture recognition are key components in the areas of aeronautical engineering, optical engineering, and many cyber-physical systems, as they can provide rich details regarding object surfaces. Novel sensor devices have been designed to improve tactile sensing, haptic perception, and surface texture recognition [1,2]. Accordingly, accurate and reliable methods for measuring the perceptual texture features of surfaces (e.g., roughness, fineness, and granularity) are in high demand, which can work together with sensors to provide integrated systems.…”

Rauheitsauswertung mit hoher lateraler Auflösung mittels räumlicher Lichtmodulatoren / Roughness evaluation with high lateral resolution by spatial light modulators

“…Um lokale Unterschiede der Rauheit festzustellen, werden die Streifen räumlich bereichsweise ausgewertet. Dies wurde bereits in vorhergehenden Artikeln vorgestellt [1,2]. Das Verfahren in [1,2]…”