Method and system for vision-based defect detection
AssigneeWistron Corporation
InventorsJie-Ci Yang, Meng-Chao Kao, Wen-Kuong Liu, Tsang-Hsing Lee, Li-Ping Pan
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Abstract
A method and a system for vision-based defect detection are proposed. The method includes the following steps. A test audio signal is outputted to a device-under-test (DUT), and a response signal of the DUT with respect to the test audio signal is received to generate a received audio signal. Signal processing is performed on the received audio signal to generate a spectrogram, and whether the DUT has an unacceptable defect with respect to the predefined auditory standard is determined by analyzing a distribution of signal strength according to the spectrogram.
Claims17
A method for vision-based defect detection of a device-under-test (DUT) comprising:
- outputting a test audio signal, wherein the test signal continuously ranges from a high frequency to a low frequency, over the passage of time;
- receiving a response signal that is generated with respect to the test audio signal;
- converting the received response signal to a received audio signal;
- performing signal processing on the received audio signal to generate a spectrogram;
- determining whether a defect exists by analyzing a distribution of signal strength, over a preset frequency range, according to the spectrogram;
- in response to determining that the DUT has the defect, determining whether the defect is unacceptable with respect to a predefined auditory standard through computer vision according to the spectrogram;
- wherein the step of determining whether the defect is unacceptable with respect to the predefined auditory standard through computer vision according to the spectrogram comprises:
- obtaining a plurality of sub-spectrograms associated with the spectrogram;
- transforming each of the sub-spectrograms into a projection curve;
- obtaining a plurality of segments associated with each of the projection curves;
- generating a feature quantification result corresponding to each of the segments of each of the projection curves;
- and
- determining whether the DUT has the unacceptable defect according to the feature quantification results and a classifier.
A defect detection system comprising:
- a signal outputting device, configured to output a test audio signal, wherein the test signal continuously ranges from a high frequency to a low frequency, over the passage of time;
- a microphone, configured to receive a response signal with respect to the test audio signal;
- an analog-to-digital converter, configured to convert the response signal to a received audio signal;
- and
- a processing device, configured to perform signal processing on the received audio signal to generate a spectrogram and determine whether a device-under-test (DUT) has an unacceptable defect by analyzing a present frequency range with respect to the predefined auditory standard through computer vision according to the spectrogram;
- wherein the processing device further pre-stores a classifier, and the processing device obtains a plurality of sub-spectrograms associated with the spectrogram, transforms each of the sub-spectrograms into a projection curve, obtains a plurality of segments associated with each of the projection curves, generates a feature quantification result corresponding to each of the segments of each of the projection curves, and determines whether the DUT has the unacceptable defect according to the feature quantification results and the classifier.
Dependencies are inferred from the claim text.