Abstract
This study is an approach to the automatic generation of dimensioning data that define solid model fully but not redundantly. The data are represented as the distance among geometric elements which compose 3 d model and the dimensioning procedure is formulated as a frame problem of AI. In the problem, geometric element data, which are explicitly extracted from the 3d model, are used as state description and their flags are used to examine the sufficiency or redundancy of dimensioning. The dimensioning is conducted by reasoning based on rules stored in the knowledge source of blackboard type expert system. Rules consist of three levels. These are: (1) overall dimensioning strategy rules that depend on the machining sequence of the part, (2) dimensioning rules that depend on the geometric feature of the part, (3) rules that generate dimensioning data while changing or examining the flag state of the part, and they are formulated so that the upper level rules invoke lower level rules. This hierarchical structure makes rule description more flexible. One example of experiments is shown and the method proposed is concluded to work properly.
