{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,9]],"date-time":"2026-05-09T17:33:42Z","timestamp":1778348022497,"version":"3.51.4"},"reference-count":26,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2023,5,31]],"date-time":"2023-05-31T00:00:00Z","timestamp":1685491200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Research Foundation of Korea (NRF) grants funded by the Korean government (MSIT)","award":["2017R1A5A1014883"],"award-info":[{"award-number":["2017R1A5A1014883"]}]},{"name":"National Research Foundation of Korea (NRF) grants funded by the Korean government (MSIT)","award":["2022R1C1C2008186"],"award-info":[{"award-number":["2022R1C1C2008186"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>With the rapid development of computer vision, vision cameras have been used as noncontact sensors for structural displacement measurements. However, vision-based techniques are limited to short-term displacement measurements because of their degraded performance under varying illumination and inability to operate at night. To overcome these limitations, this study developed a continuous structural displacement estimation technique by combining measurements from an accelerometer with vision and infrared (IR) cameras collocated at the displacement estimation point of a target structure. The proposed technique enables continuous displacement estimation for both day and night, automatic optimization of the temperature range of an infrared camera to ensure a region of interest (ROI) with good matching features, and adaptive updating of the reference frame to achieve robust illumination\u2013displacement estimation from vision\/IR measurements. The performance of the proposed method was verified through lab-scale tests on a single-story building model. The displacements were estimated with a root-mean-square error of less than 2 mm compared with the laser-based ground truth. In addition, the applicability of the IR camera for displacement estimation under field conditions was validated using a pedestrian bridge test. The proposed technique eliminates the need for a stationary sensor installation location by the on-site installation of sensors and is therefore attractive for long-term continuous monitoring. However, it only estimates displacement at the sensor installation location, and cannot simultaneously estimate multi-point displacements which can be achieved by installing cameras off-site.<\/jats:p>","DOI":"10.3390\/s23115241","type":"journal-article","created":{"date-parts":[[2023,6,1]],"date-time":"2023-06-01T02:39:47Z","timestamp":1685587187000},"page":"5241","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Continuous Structural Displacement Monitoring Using Accelerometer, Vision, and Infrared (IR) Cameras"],"prefix":"10.3390","volume":"23","author":[{"given":"Jaemook","family":"Choi","sequence":"first","affiliation":[{"name":"Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8519-5801","authenticated-orcid":false,"given":"Zhanxiong","family":"Ma","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kiyoung","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hoon","family":"Sohn","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1026","DOI":"10.1061\/(ASCE)0733-9445(2002)128:8(1026)","article-title":"Condition and damage assessment: Issues and some promising indices","volume":"128","author":"Catbas","year":"2002","journal-title":"J. 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