An endoscopic optical system for inner cylindrical measurement using fringe projection

Armando Albertazzi G. Jr.; Allan C. Hofmann; Analucia V. Fantin; João M. C. Santos

doi:10.1117/12.814540

3 October 2008 An endoscopic optical system for inner cylindrical measurement using fringe projection

Armando Albertazzi G. Jr., Allan C. Hofmann, Analucia V. Fantin, João M. C. Santos

Proceedings Volume 7155, Ninth International Symposium on Laser Metrology; 715514 (2008) https://doi.org/10.1117/12.814540
Event: Ninth International Symposium on Laser Metrology, 2008, Singapore, Singapore

Abstract

This paper presents an endoscopic optical system to measure 3D shapes of inner cylindrical surfaces that combines photogrammetry and fringe projection. The device has two identical cameras aligned with the optical axis and facing each other, two conical lenses and one 360° helical fringe projector. The helical fringe pattern is projected in the inner surface to be measured, phase shifted and acquired by both cameras. The phase patterns are used to identify corresponding points and to reconstruct the surface in a regular cylindrical mesh using an alternative approach. A prototype was built, calibrated and tested. The paper presents the results and an application to inspect internal welding seams in 150 mm (6") diameter pipelines.

Citation Download Citation

Armando Albertazzi G. Jr., Allan C. Hofmann, Analucia V. Fantin, and João M. C. Santos "An endoscopic optical system for inner cylindrical measurement using fringe projection", Proc. SPIE 7155, Ninth International Symposium on Laser Metrology, 715514 (3 October 2008); https://doi.org/10.1117/12.814540

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