Performance Improvement of a 3D Stereo Measurement Video Endoscope by Means of a Tunable Monochromator In the Illumination System

Machikhin, Alexander; Moskovskij energeticeskij institut; Russian Federation

Machikhin, A.S.; National Research University; Russia
Gorevoy, A.V.; National Research University; Russia
Batshev, V.I.; National Research University; Russia
Khokhlov, D.D.; National Research University; Russia
Kaloshin, V.A.; NPO Energomash; Russia
Perfilov, A.M.; NPO Energomash; Russia

ID: ECNDT-0023-2018
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Session: Surface Methods 2
Room: R2
Date: 2018-06-14
Time: 11:30 - 11:50

Industrial video endoscopes are the main tool for remote visual inspection and quantitative characterization of the defects on the hard-to-reach surfaces. We propose a technique to increase the effectiveness of existing stereo measurement videoscopes based on a tunable monochromatization of the illumination. Selection of a proper narrow band (NB) of light spectrum allows high contrast visualization of the defects and better precision of its geometrical parameters measurement. In this paper, we demonstrate experimentally that camera calibration under wide-band (WB) light may lead to significant inaccuracies if NB illumination is used for 3D measurements. As a result, it is necessary to calibrate the system either in a certain NB, where the inspection is the most effective, or in a few NBs with further interpolation of calibration parameters for operation in any selected spectral band. In this case, calibration and image processing software of the existing video endoscopes have to be modified. The results may be useful for the development of new remote visual inspection tools for fluorescent penetrant inspection and analysis of local spectral properties.