Research and Design of3-D Shape Measurement System Base on Digital Fringe Projection
|School||Huazhong University of Science and Technology|
|Course||Communication and Information System|
|Keywords||Digital Projection Profilometry System Model System Calibration Two-Fringe Profilometry|
With the continuous development and improvement of electronics, photoelectricdetection, image processing, and computer technology, digital projection based fringepattern profilometry(FPP) has become one of the most promising approaches fornoncontact optical measurement techniques. This technique has been widely used inmultimedia entertainment, digital multimedia, mechanical manufacture, patternrecognition, artificial intelligence, heritage protection, machinery manufacturing,industrial inspection, security due to the simplicity of implementation and high accuracy.Digital projection based fringe pattern profilometry(FPP) mostly remain theoreticalsimulation and lack experimental system, so this thesis develops a FPP prototype system.The mathematical model of this system obtains the conversion relationship between phasemap and3-d coordinates on the basis of optical imaging model of the projector and thecamera, and it corrects the optical distortion of the camera and projector to gain higherprecision. To gain the phase map of measured object, this thesis discusses a profilometrymethod which devises two different fringes based on selected periods. This profilometrymethod uses two different fringes to gain the wrapping phase map with traditionalprofilometry, and then it calculates separately to gain real absolute phase value for eachpoint in the two wrapping phase map. This profilometry method calculates quickly andaccurately, and could measure the phase map of complex objects.This thesis carries out3-d reconstruction of a plaster with the FPP system to confirmthe truth of system’s mathematical model and two fringe profilometry. This prototypesystem could provide digital projection based fringe pattern profilometry(FPP) witheffective experimental platform.