Article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images

Utilising cooling stimulation as a thermal excitation means has demonstrated profound capabilities of detecting sub-surface metal loss using thermography. Previously, a prototype mechanism was introduced which accommodates a thermal camera and cooling source and operates in a reciprocating motion sc...

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Main Authors: Doshvarpassand, Siavash, Wang, Xiangyu
Format: Journal Article
Language:English
Published: MDPI 2021
Subjects:
Online Access:http://purl.org/au-research/grants/arc/LP180100222
http://hdl.handle.net/20.500.11937/90925
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author Doshvarpassand, Siavash
Wang, Xiangyu
author_facet Doshvarpassand, Siavash
Wang, Xiangyu
author_sort Doshvarpassand, Siavash
building Curtin Institutional Repository
collection Online Access
description Utilising cooling stimulation as a thermal excitation means has demonstrated profound capabilities of detecting sub-surface metal loss using thermography. Previously, a prototype mechanism was introduced which accommodates a thermal camera and cooling source and operates in a reciprocating motion scanning the test piece while cold stimulation is in operation. Immediately after that, the camera registers the thermal evolution. However, thermal reflections, non-uniform stimulation and lateral heat diffusions will remain as undesirable phenomena preventing the effective observation of sub-surface defects. This becomes more challenging when there is no prior knowledge of the non-defective area in order to effectively distinguish between defective and non-defective areas. In this work, the previously automated acquisition and processing pipeline is re-designed and optimised for two purposes: 1—Through the previous work, the mentioned pipeline was used to analyse a specific area of the test piece surface in order to reconstruct the reference area and identify defects. In order to expand the application of this device over the entire test area, re-gardless of its extension, the pipeline is improved in which the final surface image is reconstructed by taking into account multiple segments of the test surface. The previously introduced pre-pro-cessing method of Dynamic Reference Reconstruction (DRR) is enhanced by using a more rigorous thresholding procedure. Principal Component Analysis (PCA) is then used in order for feature (DRR images) reduction. 2—The results of PCA on multiple segment images of the test surface revealed different ranges of intensities across each segment image. This potentially could cause mistaken interpretation of the defective and non-defective areas. An automated segmentation method based on Gaussian Mixture Model (GMM) is used to assist the expert user in more effective detection of the defective areas when the non-defective areas are uniformly characterised as background. The final results of GMM have shown not only the capability of accurately detecting subsurface metal loss as low as 37.5% but also the successful detection of defects that were either unidentifiable or invisible in either the original thermal images or their PCA transformed results.
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spelling curtin-20.500.11937-909252023-05-08T07:40:32Z Article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images Doshvarpassand, Siavash Wang, Xiangyu Science & Technology Physical Sciences Technology Chemistry, Analytical Engineering, Electrical & Electronic Instruments & Instrumentation Chemistry Engineering cold-active infrared thermography non-destructive testing metal loss defect detection Image processing structural health monitoring vision-based sensors ADAPTIVE HISTOGRAM EQUALIZATION CONTRAST ENHANCEMENT Image processing cold-active infrared thermography metal loss defect detection non-destructive testing structural health monitoring vision-based sensors Motion Principal Component Analysis Respiration Thermography Thermography Respiration Principal Component Analysis Motion Utilising cooling stimulation as a thermal excitation means has demonstrated profound capabilities of detecting sub-surface metal loss using thermography. Previously, a prototype mechanism was introduced which accommodates a thermal camera and cooling source and operates in a reciprocating motion scanning the test piece while cold stimulation is in operation. Immediately after that, the camera registers the thermal evolution. However, thermal reflections, non-uniform stimulation and lateral heat diffusions will remain as undesirable phenomena preventing the effective observation of sub-surface defects. This becomes more challenging when there is no prior knowledge of the non-defective area in order to effectively distinguish between defective and non-defective areas. In this work, the previously automated acquisition and processing pipeline is re-designed and optimised for two purposes: 1—Through the previous work, the mentioned pipeline was used to analyse a specific area of the test piece surface in order to reconstruct the reference area and identify defects. In order to expand the application of this device over the entire test area, re-gardless of its extension, the pipeline is improved in which the final surface image is reconstructed by taking into account multiple segments of the test surface. The previously introduced pre-pro-cessing method of Dynamic Reference Reconstruction (DRR) is enhanced by using a more rigorous thresholding procedure. Principal Component Analysis (PCA) is then used in order for feature (DRR images) reduction. 2—The results of PCA on multiple segment images of the test surface revealed different ranges of intensities across each segment image. This potentially could cause mistaken interpretation of the defective and non-defective areas. An automated segmentation method based on Gaussian Mixture Model (GMM) is used to assist the expert user in more effective detection of the defective areas when the non-defective areas are uniformly characterised as background. The final results of GMM have shown not only the capability of accurately detecting subsurface metal loss as low as 37.5% but also the successful detection of defects that were either unidentifiable or invisible in either the original thermal images or their PCA transformed results. 2021 Journal Article http://hdl.handle.net/20.500.11937/90925 10.3390/s21144811 English http://purl.org/au-research/grants/arc/LP180100222 http://creativecommons.org/licenses/by/4.0/ MDPI fulltext
spellingShingle Science & Technology
Physical Sciences
Technology
Chemistry, Analytical
Engineering, Electrical & Electronic
Instruments & Instrumentation
Chemistry
Engineering
cold-active infrared thermography
non-destructive testing
metal loss defect detection
Image processing
structural health monitoring
vision-based sensors
ADAPTIVE HISTOGRAM EQUALIZATION
CONTRAST ENHANCEMENT
Image processing
cold-active infrared thermography
metal loss defect detection
non-destructive testing
structural health monitoring
vision-based sensors
Motion
Principal Component Analysis
Respiration
Thermography
Thermography
Respiration
Principal Component Analysis
Motion
Doshvarpassand, Siavash
Wang, Xiangyu
Article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images
title Article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images
title_full Article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images
title_fullStr Article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images
title_full_unstemmed Article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images
title_short Article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images
title_sort article an automated pipeline for dynamic detection of sub-surface metal loss defects across cold thermography images
topic Science & Technology
Physical Sciences
Technology
Chemistry, Analytical
Engineering, Electrical & Electronic
Instruments & Instrumentation
Chemistry
Engineering
cold-active infrared thermography
non-destructive testing
metal loss defect detection
Image processing
structural health monitoring
vision-based sensors
ADAPTIVE HISTOGRAM EQUALIZATION
CONTRAST ENHANCEMENT
Image processing
cold-active infrared thermography
metal loss defect detection
non-destructive testing
structural health monitoring
vision-based sensors
Motion
Principal Component Analysis
Respiration
Thermography
Thermography
Respiration
Principal Component Analysis
Motion
url http://purl.org/au-research/grants/arc/LP180100222
http://hdl.handle.net/20.500.11937/90925