Industrial Applications of Speckle Techniques - Measurement of Deformation and Shape

Modern industry needs quick and reliable measurement methods for measuring deformation, position, shape, roughness, etc. This thesis is mainly concerned with industrial applications of speckle metrology. Speckle metrology is an optical non-contact whole field technique that provides the means to measure; deformation and displacement, object shape, surface roughness, vibration, and dynamic events, on rough surfaces and with a sensitivity of the order of a light wavelength. In particular, the electronic speckle metrology technique combined with advanced computers, fast frame grabbers, and image processing makes it very suitable for industrial applications. The thesis consists of four main parts. The first part presents the basic principle of speckle metrology. Some formulas and theoretical analysis are reviewed. The procedure of recording electronic speckle patterns is discussed. The phase shifting and the phase unwrapping techniques are also presented in this part. The second part considers some applications of speckle metrology technique. Four types of measurements have been done during this thesis period. They correspond to deformation measurements of solder joints on electronic device boards, 3D shape measurement with light-in-flight electronic speckle pattern interferometry, continuous deformation measurement, and cutting tool monitoring. Because the parameters under the measurements are different, the speckle metrology test beds are also different. We discuss the different set-up configurations for measuring different parameters in this part. The basic theoretical analyses are described for each application and some measurements results are included. The last part of the thesis summarizes the speckle metrology applications and potential areas of investigation for future works. The selected papers written by the author is appended at the end of the thesis. Keyword: Interferometry, ESPI, deformation measurement