Özcan Barış, Blankenbach Jörg
Geodetic Institute and Chair for Computing in Civil Engineering & Geo Information Systems, RWTH Aachen University, Mies-van-der-Rohe-Str. 1, 52074 Aachen, Germany.
Sensors (Basel). 2022 May 31;22(11):4211. doi: 10.3390/s22114211.
The roughness of a surface is a decisive parameter of a material. In rehabilitation of concrete structures, for example, it significantly affects the adhesion between the coating material and the base concrete. However, the standard measurement procedure in construction suffers from considerable disadvantages, which leads to the demand for more sophisticated methods. In a research project, we, therefore, developed a novel camera-based measurement system, which is customized to meet the prevailing requirements for practical use on construction sites. In this article, we provide an overview of the measurement system and present comprehensive examinations to evaluate the accuracy and to provide evidence of validity. First, we examined the accuracy of the system by empirically assessing both trueness and precision of measurements using three concrete specimens. Trueness was determined by comparing the surface measurements to those of a highly accurate microscope system, revealing RMSE values of around 40-50 µm. Precision, on the other hand, was assessed considering the scattering of the roughness measurements under repeat conditions, which led to standard deviations of less than 6 µm. Furthermore, to proof validity, a comparative study was conducted based on sixteen concrete specimens, which includes the sand patch method and laser triangulation as established roughness measurement methods in practice. The empirically determined correlation coefficients between all three methods were greater than 0.99, indicating extraordinarily high linear relationships. Among them, the greatest correlation was between the camera-based system and laser triangulation.
表面粗糙度是材料的一个决定性参数。例如，在混凝土结构修复中，它会显著影响涂层材料与基础混凝土之间的附着力。然而，建筑施工中的标准测量程序存在相当大的缺点，这导致了对更精密方法的需求。因此，在一个研究项目中，我们开发了一种新型的基于摄像头的测量系统，该系统经过定制，以满足在建筑工地实际使用的普遍要求。在本文中，我们对测量系统进行了概述，并进行了全面的测试，以评估其准确性并提供有效性证据。首先，我们通过使用三个混凝土试件对测量的真实性和精度进行实证评估，来检验系统的准确性。通过将表面测量结果与高精度显微镜系统的测量结果进行比较来确定真实性，结果显示均方根误差值约为40 - 50微米。另一方面，考虑到重复条件下粗糙度测量的离散性来评估精度，结果导致标准偏差小于6微米。此外，为了证明有效性，基于16个混凝土试件进行了一项对比研究，其中包括实际中已确立的粗糙度测量方法——砂铺法和激光三角测量法。通过实证确定的这三种方法之间的相关系数均大于0.99，表明它们具有极高的线性关系。其中，基于摄像头的系统与激光三角测量法之间的相关性最强。
