Non-Contact Crack Visual Measurement System Combining Improved U-Net Algorithm and Canny Edge Detection Method with Laser Rangefinder and Camera

Cracks are the main damages of concrete structures. Since cracks may occur in areas that are difficult to reach, non-contact measurement technology is required to accurately measure the width of cracks. This study presents an innovative computer vision system combining a camera and laser rangefinder...

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Main Authors: Sizeng Zhao, Fei Kang, Junjie Li
Format: Article
Language:English
Published: MDPI AG 2022-10-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/12/20/10651
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author Sizeng Zhao
Fei Kang
Junjie Li
author_facet Sizeng Zhao
Fei Kang
Junjie Li
author_sort Sizeng Zhao
collection DOAJ
description Cracks are the main damages of concrete structures. Since cracks may occur in areas that are difficult to reach, non-contact measurement technology is required to accurately measure the width of cracks. This study presents an innovative computer vision system combining a camera and laser rangefinder to measure crack width from any angle and at a long distance. To solve the problem of pixel distortion caused by non-vertical photographing, geometric transformation formulas that can calculate the unit pixel length of the image captured at any angle are proposed. The complexity of crack edge calculation and the imbalance of data in the image are other problems that affect measurement accuracy, and a combination of the improved U-net convolutional networks algorithm and Canny edge detection method is adopted to accurately extract the cracks. The measurement results on the different concrete wall indicate that the proposed system can measure the crack in a non-vertical position, and the proposed algorithm can extract the crack from different background images. Although the proposed system cannot achieve fully automated measurement, the results also confirm the ability to obtain the crack width accurately and conveniently.
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spelling doaj.art-ecb5c987917e4416b2f3c61b2f652b772023-11-23T22:48:13ZengMDPI AGApplied Sciences2076-34172022-10-0112201065110.3390/app122010651Non-Contact Crack Visual Measurement System Combining Improved U-Net Algorithm and Canny Edge Detection Method with Laser Rangefinder and CameraSizeng Zhao0Fei Kang1Junjie Li2School of Hydraulic Engineering, Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024, ChinaSchool of Hydraulic Engineering, Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024, ChinaSchool of Hydraulic Engineering, Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024, ChinaCracks are the main damages of concrete structures. Since cracks may occur in areas that are difficult to reach, non-contact measurement technology is required to accurately measure the width of cracks. This study presents an innovative computer vision system combining a camera and laser rangefinder to measure crack width from any angle and at a long distance. To solve the problem of pixel distortion caused by non-vertical photographing, geometric transformation formulas that can calculate the unit pixel length of the image captured at any angle are proposed. The complexity of crack edge calculation and the imbalance of data in the image are other problems that affect measurement accuracy, and a combination of the improved U-net convolutional networks algorithm and Canny edge detection method is adopted to accurately extract the cracks. The measurement results on the different concrete wall indicate that the proposed system can measure the crack in a non-vertical position, and the proposed algorithm can extract the crack from different background images. Although the proposed system cannot achieve fully automated measurement, the results also confirm the ability to obtain the crack width accurately and conveniently.https://www.mdpi.com/2076-3417/12/20/10651computer visioncrack measurementU-netconvolutional neural networkstructural health monitoringartificial intelligence
spellingShingle Sizeng Zhao
Fei Kang
Junjie Li
Non-Contact Crack Visual Measurement System Combining Improved U-Net Algorithm and Canny Edge Detection Method with Laser Rangefinder and Camera
Applied Sciences
computer vision
crack measurement
U-net
convolutional neural network
structural health monitoring
artificial intelligence
title Non-Contact Crack Visual Measurement System Combining Improved U-Net Algorithm and Canny Edge Detection Method with Laser Rangefinder and Camera
title_full Non-Contact Crack Visual Measurement System Combining Improved U-Net Algorithm and Canny Edge Detection Method with Laser Rangefinder and Camera
title_fullStr Non-Contact Crack Visual Measurement System Combining Improved U-Net Algorithm and Canny Edge Detection Method with Laser Rangefinder and Camera
title_full_unstemmed Non-Contact Crack Visual Measurement System Combining Improved U-Net Algorithm and Canny Edge Detection Method with Laser Rangefinder and Camera
title_short Non-Contact Crack Visual Measurement System Combining Improved U-Net Algorithm and Canny Edge Detection Method with Laser Rangefinder and Camera
title_sort non contact crack visual measurement system combining improved u net algorithm and canny edge detection method with laser rangefinder and camera
topic computer vision
crack measurement
U-net
convolutional neural network
structural health monitoring
artificial intelligence
url https://www.mdpi.com/2076-3417/12/20/10651
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AT feikang noncontactcrackvisualmeasurementsystemcombiningimprovedunetalgorithmandcannyedgedetectionmethodwithlaserrangefinderandcamera
AT junjieli noncontactcrackvisualmeasurementsystemcombiningimprovedunetalgorithmandcannyedgedetectionmethodwithlaserrangefinderandcamera