Spatial data structures for version management of engineering drawings in CAD database

摘要

In the engineering database system, multiple versions of a design, including engineering drawings, should be managed efficiently. Spatial data structures can manage spatial objects in a drawing efficiently. The paper proposes extended spatial data structures for efficient management of multiversion engineering drawings. The R-tree is adapted as a basic data structure. The efficient mechanism to manage the difference between drawings is introduced to the R-tree to eliminate redundant duplications and to reduce the amount of storage required for the data structure. Extended data structures of the R-tree, called MVR and MVR* trees, are developed and the performances of these trees are evaluated. A series of simulation tests shows that, compared with the basic R-tree, the amounts of storage required for the MVR and MVR* trees are reduced to 50% and 30%, respectively. The search efficiencies of the R, MVR, and MVR* trees are almost the same.