Real‐time illumination adjustment for video deflectometers

Structural Control and Health MonitoringVolume 29, Issue 5 e2930 RESEARCH ARTICLE Real-time illumination adjustment for video deflectometers Da Yang, Da Yang Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai University, Shanghai, ChinaSearch for more papers by this authorShuiqiang Zhang, Shuiqiang Zhang School of engineering, Huzhou University, Huzhou, ChinaSearch for more papers by this authorShuo Wang, Shuo Wang Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai University, Shanghai, ChinaSearch for more papers by this authorQifeng Yu, Qifeng Yu College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, ChinaSearch for more papers by this authorZhilong Su, Corresponding Author Zhilong Su [email protected] Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai University, Shanghai, China Correspondence Dongsheng Zhang, Ph.D., Zhilong Su, Ph.D.; School of Mechanics and Engineering Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China. Email: [email protected] and [email protected]Search for more papers by this authorDongsheng Zhang, Corresponding Author Dongsheng Zhang [email protected] orcid.org/0000-0001-6432-3579 Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai University, Shanghai, China Correspondence Dongsheng Zhang, Ph.D., Zhilong Su, Ph.D.; School of Mechanics and Engineering Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China. Email: [email protected] and [email protected]Search for more papers by this author Da Yang, Da Yang Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai University, Shanghai, ChinaSearch for more papers by this authorShuiqiang Zhang, Shuiqiang Zhang School of engineering, Huzhou University, Huzhou, ChinaSearch for more papers by this authorShuo Wang, Shuo Wang Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai University, Shanghai, ChinaSearch for more papers by this authorQifeng Yu, Qifeng Yu College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, ChinaSearch for more papers by this authorZhilong Su, Corresponding Author Zhilong Su [email protected] Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai University, Shanghai, China Correspondence Dongsheng Zhang, Ph.D., Zhilong Su, Ph.D.; School of Mechanics and Engineering Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China. Email: [email protected] and [email protected]Search for more papers by this authorDongsheng Zhang, Corresponding Author Dongsheng Zhang [email protected] orcid.org/0000-0001-6432-3579 Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, School of Mechanics and Engineering Science, Shanghai University, Shanghai, China Correspondence Dongsheng Zhang, Ph.D., Zhilong Su, Ph.D.; School of Mechanics and Engineering Science, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China. Email: [email protected] and [email protected]Search for more papers by this author First published: 22 January 2022 https://doi.org/10.1002/stc.2930 Funding information: the National Key R&D Program of China, Grant/Award Number: 2018YFF01014200; China Postdoctoral Science Foundation; National Natural Science Foundation of China, Grant/Award Numbers: 11727804, 11872240, 12002197, 12072184, 51732008 Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Summary Video deflectometers, as a real-time, contactless optical means, show great potentials in monitoring structural deflections. However, variations of illumination conditions pose a severe challenge on accurate measurement. In this study, a strategy with global illumination adjustment has been proposed to dynamically change the exposure time of the camera to achieve an optimal intensity distribution. An illumination-robust digital image correlation (DIC) algorithm is also proposed for accurate, real-time video deflection measurement. The combined method improves robustness and accuracy of measurement in two ways, which includes globally dynamic intensity adjustment and modification of the grayscale arrays in subsets during the correlation process. Experiments in the laboratory environment and applications in the outdoor environment have been conducted to validate the performance of the proposed method. The results show that the proposed method is feasible and accurate in real-time deflection measurement in the outdoor environment with variations of environmental illumination. Volume29, Issue5May 2022e2930 RelatedInformation