• Optics and Precision Engineering
  • Vol. 17, Issue 5, 1187 (2009)
SUN Hui-xian*, ZHANG Yu-hua, and LUO Fei-lu
Author Affiliations
  • [in Chinese]
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    DOI: Cite this Article
    SUN Hui-xian, ZHANG Yu-hua, LUO Fei-lu. Visual inspection of surface crack on labyrinth disc in aeroengine[J]. Optics and Precision Engineering, 2009, 17(5): 1187 Copy Citation Text show less

    Abstract

    The visual inspection based on an endoscope has played an important role in modern fault diagnosis of aeronautic engines. An inspection approach to surface cracks of the aperture on an aeroengine labyrinth disc is studied based on the industrial videoscope in this paper.After analysis on the appearance reasons of the cracks and their characteristics,an automatic recognition method for surface cracks is proposed based on a localization-recognition model and a novel fuzzy fast Hough transform is presented to detect the circular contour to locate the aperture. Then,an interesting region is defined around the aperture,and the image in the interesting region is binarized by a threshold and the binary image is thinned by a morphological method. Moreover,the chain codes in the image are analyzed to recognize the crack. The results of circular contour detection by the proposed fuzzy fast Hough Transform are compared with those by the Standard Hough transform and randomized hough Transform,respectively. The results show that the fuzzy fast Hough transform can detect the contour and can locate the aperture quickly and accurately. A crack detection experiment is carried out for 80 aperture images,and the results indicate that the detecting accuracy is 91.2%.
    SUN Hui-xian, ZHANG Yu-hua, LUO Fei-lu. Visual inspection of surface crack on labyrinth disc in aeroengine[J]. Optics and Precision Engineering, 2009, 17(5): 1187
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