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Title:
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Instantaneous velocity displacement and contour measurement by use of shadow moiré and temporal wavelet analysis.
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Author:
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Tay, Cho Jui.; Quan, Chenggen.; Fu, Yu.; Huang, Yuanhao.
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Copyright year:
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2004 |
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Abstract:
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A temporal wavelet analysis method is proposed for velocity, displacement, and three-dimensional
surface-profile measurement of a continuously deforming object by use of the shadow moire´ technique.
A grating is placed close to a deforming object, and its shadow is observed through the grating. The
moire´ fringe patterns, generated by the interference of the grating lines and their shadows, are captured
by a high-speed CCD camera with a telecentric gauging lens. Instantaneous frequency of gray-value
variation is evaluated point by point with the continuous wavelet transform. From the instantaneous
frequency of each point on the object, the velocity, displacement, and high-quality surface profile at
different instants can be retrieved. In this application, two specimens are tested to demonstrate the
validity of the proposed method: One is a small coin with a rigid body motion, and the other is a simply
supported beam subjected to a central point load. The results are compared with those obtained from
temporal Fourier-transform and mechanical stylus methods. |
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Subject:
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DRNTU::Science::Physics::Optics and light. |
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Type:
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Journal Article |
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Series/ Journal Title:
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Applied Optics |
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Research Centre:
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Temasek Laboratories |
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Rights:
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This paper was published in [Applied Optics] and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: [http://www.opticsinfobase.org/ao/abstract.cfm?uri=ao-43-21-4164]. Systematic or multiple reproduction or distribution to multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law. |
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Version:
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Published version |
