Surface 3D deformation measurements obtain valuable data for reliability analysis of engineering structures. For micro-scale structures in particular, direct measurements provide indispensable data for any physics-based assessment. The dissertation researches several one-camera based computer-vision methods, which include the Projected Speckle Digital Correlation (PSDC) and the Digital Fringe Projection (DFP) for out-of-plane deformation and the integrated DFP and Digital Image Correlation (DIC) method for all three components of displacement measurement. For the PSDC, four different system configurations are studied. A convenient, real-time image subtraction based calibration method is proposed for determining the system sensitivity factor. A systematic, linearly varying error term in measurements across the surface is identified and determined both analytically and experimentally. A linear regression based calibration method is proposed to compensate the error and improve the measurement accuracy. Measurement accuracy of the DFP method was improved by several proposed new techniques, including, a multiplicative iterative grating pitch pre-correction algorithm to realize equal-pitched surface grating patterns a virtual reference phase plane to facilitate the surface profiling of irregular shaped objects a Quality Guided Path Following (QGPF) phase unwrapping method and a real-time image subtraction based calibration. The work paves a framework for integrating these methods and realizing simultaneous three-dimensional measurement. The 3D deformation is successfully measured by the integrated DFP and DIC method.
展开▼
