Gear Measurement by Projection Moire Technology

• Main Authors: Jr-Yi Chen, 陳智怡
• Other Authors: Yi-Cheng Chen
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/m3z3xk

碩士 === 國立中央大學 === 光機電工程研究所 === 105 === In recent years, non-contact measurement becomes a mainstream technique for gear detection. Different from the traditional contact probe measurement method, non-contact measurement contains some advantages such as high efficiency and without the restriction from probe size or gear material. Therefore, in this study, a non-contact optical measurement method was adopted to gear detection. For the system architecture, a halogen lamp was chosen as the light source and a collimated beam was produced by autocollimator. Further, moiré fringe was built up as the collimated beam going through the two linear grating. Finally, the moiré fringe projected on the tooth surface and the errors of gear would be calculated by the image capture system. The process of the measurement system includes: (1) Placing the calibration piece at the testing position first. (2) Executing the distortion correction by CCD sensor in case of the image distortion caused by the optical elements. (3) Replacing the calibration piece with the gear after the correction step being completed. (4) Capturing the deformation of the moiré fringe projected on the tooth surface. (5) Calculating the phase change of the measured points by the phase shift technology and finally gather the available gear three-dimensional contour by the phase unwrapped technology. In addition, in order to verify the accuracy of the system, a real tooth profile measured by the coordinate measuring machine (CMM) would define as the reference profile. The tooth topography, tooth profile and lead errors could be obtained by comparing the deviation between measured and referenced data, and calculating the perpendicular distance from measurement point to the surface. The results of the spur gear show that the accuracy of the system developed by this research are 2.81μm. In this study, the high sensitivity of the moiré fringe was applied for the gear detection. The image was captured by the CCD sensor, and the data of the optical measurement points were compared with the ideal surface with the parameters of lens distortion correction and image processing. The method is not only implemented a high efficiency non-contact gear detection system, but also achieved the goals of high precision and resolution by adjusting the density of the moiré fringe and capturing the superimposed image by microscope. The ultimate goal of rapid detection of gears may be realized by combining the non-contact measuring system with industrial machine in the future.