Development of high-speed surface roughness measurement method by multi-wavelength imaging

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04221
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 18020:Manufacturing and production engineering-related
• Research Institution: Industrial Research Institute of Shizuoka Prefecture
• Principal Investigator: Nakano Masaharu 静岡県工業技術研究所, 浜松工業技術支援センター光科, 上席研究員 (90707837)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 表面粗さ / 表面性状 / 測色 / イメージング / 色彩計 / 非接触

Outline of Final Research Achievements

We have developed a method for estimating the surface roughness from the color distribution of the scattered light on the sample surface measured by using a two-dimensional colorimeter. It was showed that the distribution of colorimetric value of the scattered light, which mapped to a CIE 1931 xy chromaticity diagram, was varied according to the surface roughness. We clarified the factors affected the measurement sensitivity, which is the amount of change in the colorimetric distribution depending on the surface roughness, and the measurement variation, constructed a measurement system optimized those factors. It was confirmed that a roughness parameter, the arithmetical mean height of a surface 'Sa,' was estimated with an accuracy of 0.69 μm within the range from 0.7 μm to 11 μm near the center of the measurement surface area using our optimized measurement system.

Free Research Field

光計測

Academic Significance and Societal Importance of the Research Achievements

製品の品質検査工程において、加工面の表面粗さを評価するために、目視や触診といった官能検査が使われてきた。官能検査では、高度な検査技術を有する人材が必要で、定量的な品質管理が難しいことが課題となっている。本手法により、短時間で粗さを測定することが可能になれば、定量的な全数検査をインラインで行うといった高レベルの品質管理での利用を期待できる。そのためには、測色値の分布と粗さの関係を評価し、本手法による粗さの推定精度を明らかにする必要がある。