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Proceedings Paper

Non-target image technique for spatial-temporal structural responses measurement
Author(s): C. C. Chang; Yunfeng Ji
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Paper Abstract

Image sequences recorded by high-resolution digital video cameras contain vast amount of spatial-temporal information of targeted objects. With the rapid increase of image resolution, these digital cameras can now be used to measure three-dimensional complex motion of structures with sufficient accuracy for the purpose of modal analysis or health monitoring applications. In this paper, a measurement technique based on image sequence analysis is proposed for extracting spatial-temporal responses of continuous structures. Two digital cameras are used to record two-dimensional (2D) image sequences of a three-dimensional (3D) structural vibration response. This structural vibration response is reconstructed using the two 2D image sequences through the epipolar geometry theory without the use of any pre-installed targets. The obtained displacement response provides a more direct way to quantify the modal properties of the structure. To demonstrate, a laboratory test was conducted to measure the free vibration of a cantilever steel rod. Results show that the proposed technique can obtain excellent results as compared to the analytical solution. The proposed technique provides a low-cost alternative to measure 3D vibration of low-frequency flexible structures such as bridge cables in a non-contact and non-target fashion.

Paper Details

Date Published: 10 April 2007
PDF: 10 pages
Proc. SPIE 6529, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2007, 65291K (10 April 2007); doi: 10.1117/12.715989
Show Author Affiliations
C. C. Chang, Hong Kong Univ. of Science and Technology (Hong Kong China)
Yunfeng Ji, Hong Kong Univ. of Science and Technology (Hong Kong China)


Published in SPIE Proceedings Vol. 6529:
Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2007
Masayoshi Tomizuka; Chung-Bang Yun; Victor Giurgiutiu, Editor(s)

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