2-D Optical Super Heterodyne Method For The Fringe Patterns Processing Of Photomechanics

A new processing method for the fringe patterns—-2-D Optical Super Heterodyne (2-D OSH) technique, is presented in this thesis. The advantages of this method are real time, automaed, high sensitivity, high precision and conveniencefor the industry production.This thesis is based on the carrier theory of communication technique.The relationships between the electronic technique and the photomechanical technique are established. The carrier of photomechanics, the modulation ofcarrier, the complete demodulation and the uncomplete demodulation in heterodyne manner, which enriched and developed the photocarrier theoryare described. The relationships between the photocarrier technique and the phase-shift technique are also established, which make it possible to integrate thesestwo techniques together. The 2-D OSH technique is formed by combining the advantages of both.The model of 2-D Spatical Phase Detector (2-D SPD) which explains the demodulation of photocarrier, the Digital Image Shearography and the phase-shift of Scanning Moire method, and the carrier-based automated phase-shift method which has the advantages of less memory, less time consuming and automated phase-shift are presented. The sensitivity and error analysis of phase-shift technique are discussed.Three applications—the displacement field measurement of crack tip, the geometry distoration of T.V cam .era and the 3-D topography—are shown. They involve the field of Fracture Mechanics, Digital Image Processing and Computer Vision. The successes of these examples display it's great application prospects.