Assembly constraint solving for re-imported shape geometry after modification

Abstract

Product data integration is inevitable for the applications of Computer Aided Engineering /Manufacturing (CAE/CAM). The data integration problem becomes acute when the geometric modeling work is outsourced for a project to a vendor who is using the Source CAD System (SCS). The product design is based on a recursive method which requires that revised imported geometry models have to be re-imported in the Target CAD System (TCS) for the downstream applications. These re-imported models could be difficult to handle particularly for Original Equipment Manufacturer (OEM) companies. The iterative nature of the product design requires several operations including the assembly operation to be performed on the reimported files by the same process as the first import have been dealt with. Two methodologies for data integration of re-imported models are discussed. The neutral models either contain the Exchangeable Persistent Identifiers (EPiDs) or do not contain any identifier at all. The problems in the implementation of EPiDs for SCSs and TCSs are discussed with proposed improvements. EPiDs have a consistency problem upon modification from the SCS and then delivery to the TCS. The consistency problem is based on how to handle the neutral file and thus EPiD. In case the neutral file does not contain any identifier, the history-free approach basis is used for the unit vector comparison to solve this problem. The proposed methods may reduce the lead time that is wasted on fixing or assembling the re-imported geometries