An intelligent approach for dimensioning completeness inspection in 3D based on transient geometric elements

Abstract

Complete dimensioning plays an important role in digital product design. This paper proposes an intelligent reasoning approach to inspect the dimensioning completeness for 3D mechanical parts. Firstly, the problem of inspecting the dimension completeness is transformed into the problem of determining the geometric element (GE) constrained states. Then, 8 types of general geometric elements are decomposed into basic geometric elements (BGE) and basic dimensional elements (BDE), and an intermediate model named transient geometric element (TGE) is proposed to reflect the influences of geometric constraints (GC) on the BGEs. Thereafter, 3 types of complex constraints are decomposed into 6 types of simple constraints, which are then utilized to form the generation rules of the TGEs. Then, an upgrading geometric reasoning method of creating new TGEs is developed to get the BGE’s constrained state and the dimension usage status. Finally, the completeness states of dimensions are acquired according to the dimension usage status and the BGE’s constrained states. The presented approach is tested by a pre-dimensioned mechanical part composed of many typical geometric elements and constraints, and the result demonstrates that the dimensioning completeness states can be successfully inspected.