Detection of Micro-Cracks on Highly Specular Reflectors: Dimensioning a Vision Machine Based on Optical Properties

Rémi Gilblas (1) , Thierry Sentenac (1) , Jean-José Orteu (1) , Mickaël Sauvée (2) , Guillaume Sierra (3) , Florian Gacoin (4) , Olivier Guillaumon (3)

1 ICA - Institut Clément Ader
2 ALCI SAS
3 MAP Coatings
4 Airbus Defence and Space [Toulouse]

This paper describes the complete dimensioning of a method and apparatus dedicated to the automatic detection of defects on optical mirror-like components called optical solar reflector (OSR), which are used to ensure the thermal control of satellites. First, the requirements of the method are defined according to the properties of the OSR (multilayer and semitransparent) and the defects to be detected. The defect dimensions are then measured and exhibit very dispersed micrometric values. Second, the optical characterization of the OSR and its sublayers is conducted, enabling the dimensioning of the machine with regard to the localization of the defect (surface, interface, or volume). Third, a semi-industrial prototype is developed and evaluated through two kinds of experiments. The first experiment illustrates the production capacity of the prototype and the second the measurement capability. Results showed that the prototype exceeded the initial requirements and could be used to replace the currently used control with confidence.

Mots clés: Spectrometry; Optical microscopy; Satellite protection; Defect detection; Optical properties

Domaines: Sciences de l'ingénieur [physics]

Rémi Gilblas, Thierry Sentenac, Jean-José Orteu, Mickaël Sauvée, Guillaume Sierra, et al.. Detection of Micro-Cracks on Highly Specular Reflectors: Dimensioning a Vision Machine Based on Optical Properties. IEEE Sensors Journal, 2017, 17 (23), p.7901 - 7907. ⟨10.1109/JSEN.2017.2762359⟩. ⟨hal-01633655⟩