| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 96 === The objective of the study is to develop a surface profile measurement system using a programmable fringe reflection method or a structured fringes projection method on a PC-based 4-axis machine. The developed system mainly consists of a PC-based 4-axis machine, a CCD Camera, a programmable LCD as a fringe projector, a screen on which the reflected fringe would be projected, a set of measurement software, and a PC. The surface roughness and the 2D profile of the flat composite specimens with print-through phenomenon could be measured simultaneously using the fringe reflection method, based on the calibration results. The surface roughness of the flat composite specimens was determined by the calibrated linear equation between the surface roughness Rmax of the test specimens measured with a precision stylus instrument and the average fringe width reflected from the test specimens. The profile error between the maximum peak and valley of the test specimen can be calculated, according to the calibrated factor between profile deviation measured by the stylus instrument and that of the optical measurement system. The mean roughness error was about Rmax 0.23 μm, and the mean profile error was about 0.29 μm. For the structured fringes projection method, the 3D surface profile of the test objects with scattered surface could be measured by the 4-step phase shifting algorithm assisted with the space encoding technique using the Gray codes, based on the calibrations results of the system parameter k. The measuring error of the stepped specimen was about 22 μm, and that of the 3D freeform surface was about 65.7 μm, through a comparison between the measurements of the developed system and the measurements of a CNC coordinate measuring machine. The measuring error of the inclination angle was about 0.80° and the flatness error was about 11 microns for an inclined surface.
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