Research Of Key Technologies In Close Range Photogrammetry Applied In Reverse Engineering

Since its coming into being in the 80s'of the last century, Reverse Engineering (RE) has become to an independent and comprehensive field in CAD/CAM. Data acquisition– measuring– is the premier technique in RE. For modern tasks which involve large volume, complicated structures and free form surfaces targets, the combination of close range photogrammetry and structured light grating projection measuring is the most fast and efficient method. The photogrammetry establishes a coordinate group of artificial marks which forms the reference set for merging point-clouds acquired by the structured light method measurement. This combination features with both the high efficiency of structured light method and the elimination of cumulative errors profited from photogrammetry.This thesis researches the photogrammetry part in this combination method. In this paper, the concept and development of RE and various data acquisition methods are introduced, and the principle of these two types of technology with their ligament– the artificial marks– is presented. Along with the process of photogrammetry, the range of this research is showed as the following:1. Recognition and distinguishing of both kinds of marks by structured pattern recognition method. A method based on the geometry features and construction rules was designed for decoding of the coded marks.2. The regulation for deployment of artificial masks was prescribed and a new topology model was built to solve the stereo matching for...