A part image reconstruction system for reverse engineering of design modifications

Abstract When the CAD model of an existing part is not available, the reverse engineering involved in the creation of such a model is typically time consuming, tedious, and potentially a source of error. Currently, geometric measurements from the surface of a prototype are extracted manually or through a coordinate measuring machine and input to a CAD system. This paper outlines a methodology for the development of part image reconstruction systems (PAIRS). The system developed by the authors is microcomputer-based and uses a noncontact technique to extract 3-D data from the surface of parts. Algorithms for data acquisition are discussed. Procedures for processing the data into a polygon mesh representation and orthographic projections are detailed. Sample results are also explained.