The Research of Multi-level Compound Surface Measurment and Reconstructed with Precision-Guide

• Main Authors: Shoou-Jen Tiau, 刁守仁
• Other Authors: Shuo-Jen Lee
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/68515599170252555012

碩士 === 元智大學 === 機械工程研究所 === 83 === With the integration of CAD/CAM systems and computer controlled coordinate measuring mechine（CMM） , reverse engneering has emerged as an important design tool in recent years. The techniques mainly involve measuring and digitization from physical parts and surface model reconstruction. In this thesis, the physical parts was scanned by CNC type coordinate measuring mechine equipped with a touch- trigger probe. A correcting procedure for the probe center offset is developed in this thesis. Then, using the surface model was reconstructed from measured points data by the cubic-spline methode. Features of this thesis are: (1)we use the quadtree- like method to achieve the multi-level measuring strategy. (2)The zero-crossing method is applied to detect the characteristic curve of compound suface, then we can found the boundary (edge)variety sharply. (3) The block is a unit use to estimate the accuracy of the reconstructed surface achieved by compare the predict points and check points.If the reconstructed-error larger than the specific limit,this block will be redivided and remeasured again, until all blocks reach the precision requirement. In the end, the entire measurment strategy, the edge detect result, and the reconstructed cubic- spline surfaces and its error analysis will be proved by two examples, one is a multi-slope magnatic set, another is a semi- sphere set.