Browse > Article
http://dx.doi.org/10.3795/KSME-A.2002.26.12.2535

A Study on Measurement of Micro Weld Deformation by Using PS-ESPI  

Lee, Gun-Ha (한국과학기술원 기계공학과)
Kim, Ji-Tae (한국과학기술원 기계공학과)
Na, Suck-Joo (한국과학기술원 기계공학과)
Publication Information
Transactions of the Korean Society of Mechanical Engineers A / v.26, no.12, 2002 , pp. 2535-2540 More about this Journal
Abstract
ESPI is a noncontact, nondestructive and relatively fast inspection method. For these reasons ESPI is being applied as a valuable tool in the nondestructive evaluation of structural components. Phase shifting ESPI is used more effectively than the traditional ESPI because spatial resolution of small object displacements are improved and numerical phase values are obtained for all pixels in the image. Consequently the quantitative measurement of deformation is possible. ESPI fringe patterns are contaminated with high levels of speckle noise. Therefore the phase image is to be smoothed to remove the noise and obtain a better signal-to-noise ratio. In this study, smoothing is done by phase shifting convolution to avoid smoothing errors close to the 2$\pi$ phase ambiguities in the deformation phase image, and median filter is used as a smoothing filter.
Keywords
ESPI; Phase Shifting; Unwrapping; Smooth Filter;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Wong, W. O., and Chan, K. T., 1998, 'Quantitative Vibration Amplitude Measurement with Time_Averaged Digital Speckle Pattern Inerferometry,' Optics & Laser Technology, pp. 317-324   DOI   ScienceOn
2 Lokberg, O. J., 1993, 'Recent Developments in Video Speckle Interferometry,' Speckle Metrology, pp. 157-194
3 Surrel, Y., 1993, 'Phase Stepping : A New Self-Calibrating Algorithm,' Applied Optics, pp. 3598-3600
4 Ritter, R., Galanulis, K., Winter, D., Muller, E. and Breuckmann, B., 1997, 'Notes on the Application of Electronic Speckle Patterm Interferometry,' Optics and Lasers in Engineering, pp. 283-299   DOI   ScienceOn
5 Tong, J., Zhang, D., Li, H. and Xu, G., 1997, 'Automatic Analysis of Three-Dimensional Displacement Field Using ESPI,' Optics and Lasers in Engineering, pp. 515-529   DOI   ScienceOn
6 Creath, K., 1985, 'Phase-Shifting Speckle Interferometry,' Applied Optics, pp. 3053-3058
7 Kjell, J. G., 1996, 'Optical Methodology(2nd Edition),' Wiley, pp. 177-273
8 Kim, H. J., 'A Study on Measurement System for Micro Weld Distortion Using Laser Speckle,' M.S. Thesis, KAIST
9 Vikhagen, E., 1990, 'Nondestructive Testing by Use of TV Holography and Deformation Phase Gradient Calculation,' Applied Optics, pp. 137-144