The Study of an Optical 3D Coordinates Measurement System with a Vertical Moving CCD

• Main Authors: Tzu-Pei Liu, 劉咨貝
• Other Authors: Ching-Chih Tai
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/70664544327369431285

碩士 === 大同大學 === 機械工程學系(所) === 97 === In this research, a revised similar triangle algorithm based upon the pinhole imaging principle was proposed to establish a 3D optical measurement system with a vertical moving CCD. Within the range of depth of field that allows for CCD’s focus length, set up two altitude positions of the lens. Measure the values of view of field and acquire image data of measured objects corresponding two altitude positions of the lens. The space coordinates that specially examined the measuring point of objects can be obtained through the revised similar triangle algorithm. The revised similar triangle algorithm is based upon simple linear equations system. It is superior to general systems that need relatively complicated coordinate transformations and non-linear calculations. This research makes a simple measuring tool with a 0.5-mm precision to measure the values of view of field and depth of field at the same time. These values can be implemented to calculate the focus length of CCD. This research probes into the ring light source, the size of measured object, the search law for image coordinates and the resolution of image capture board to analyze influence on the improvement for measuring accuracy. The experimental results reveal that the resolution of image capture board is a main factor which improves the precision of measurement, except the ring light source.