Patent ID: 11954845
Assignee: AIRBUS SAS
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 2:
3. A non-transitory computer-readable data carrier having stored thereon a computer program product comprising instructions which, when the program is executed by a computer, are configured to cause the computer to carry out a method for determining whether a part suffers from fatigue damage, the method comprising:
1.1 with a scanning microscope device, imaging the sample surface so as to obtain a sample image potentially containing the fatigue striations;
1.2 with an image patch selecting device, selecting a sample image patch potentially containing the fatigue striations from the sample image for further processing;
1.3 with a pre-processing device:
normalizing the sample image patch by performing, on the sample image patch, any of: a Gaussian filter operation; and/or a histogram equalization; and/or an image binarization and subsequent morphological operation, such as including erosion, dilation or skeleton-operations; and/or a frequency domain self-filtering operation; and/or a window operation or applying a Hamm window; and/or a normalization operation to normalize intensity values to a fixed range; and enhancing line-like regular structures contained in the sample image patch to obtain a normalized image patch;

1.4 with an autocorrelation device, determining an autocorrelation of the normalized image patch to obtain an autocorrelation image patch;
1.5 with a Radon transform device, performing a Radon transform of the autocorrelation image patch to obtain a transformed image patch;
1.6 with a frequency analysis device, performing a spectral analysis of the transformed image patch and determining a power spectrum of the transformed image patch;
1.7 with a striation property determining device, determining, from the power spectrum, at least one striation property that is suitable to indicate a presence of fatigue striations in the sample image patch; and
1.8 with a fatigue damage determining device, determining, if a peak in the power spectrum exceeds a predetermined threshold, that the part suffers from fatigue damage, and determining, if the peak does not exceed the predetermined threshold, that the part does not suffer from fatigue damage.