Light Scattering Speckle Measurement of Surface Roughness of the Cold Rolled Steel with Oil Film Coating

• Main Authors: Lin, Yuh-Horng, 林昱宏
• Other Authors: Tze-Chi Hsu, Ching-An Shao
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/26793460383782219985

碩士 === 元智工學院 === 機械工程學系 === 84 === A non-contact optical technique is developed for measuring roughness of cold rolled products with oil film coating in real-time. The technique is based upon the laser scattering speckle pattern which is formed at an observing plane due to the random wave- front plane, and transformed into the specific configuration of the surface roughness by using optical statistical theory. Furthmore using image processing to eliminate the influence from the oil film coating is adopted. The influence involves the bright spot which is caused by the incident light reflected directly from outer surface of oil coating, and tortuous speckle which is caused by refraction. The former disortion is solved by filterring spot directly and filling the new value being available from average gray around the spot, the latter distortion is corrected by simulating the path of light incident into oil film.