Development of multiwavelength digital holographic endoprobe system for small pipe inspection using profilometry and spectroscopy

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560521
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Measurement engineering
• Research Institution: Shimane University
• Principal Investigator: YOKOTA Masayuki 島根大学, 総合理工学研究科(研究院), 教授 (80323335)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: ディジタルホログラフィ / 波長多重

Outline of Final Research Achievements

Multiwavelength digital holography for the investigation of a straight pipe inner surface has been proposed. To classify defects on a pipe inner surface, the intensity image reconstructed by three wavelengths (Red, Green and Blue) are used and that enables us to visualize color image of the pipe inner surface. By using the spectral reflectance obtained by each intensity image, it is possible to classify crack and verdigris in the pipe inner surface.
In addition, the height profile of the pipe inner surface could be obtained by two-wavelength holographic contouring technique. Object having a thickness of 0.1mm could be detected using the technique. For the measurement using a cone-shaped mirror, the inclination and positional error of the mirror becomes problem. The algorithm for correcting the effect brought by such error has been proposed and has been shown that the error can be effectively reduced using the correction process using the proposed algorithm.

Free Research Field

光応用計測