No abstract

CAx systems typically encode the semantics of shapes as so-called parametric features on different levels of abstraction. Here we discuss an approach that combines feature-based parametric modelling with techniques from the field of knowledge representation and ontological reasoning. Parametric models refer to feature ontologies that model feature semantics on several levels of granularity. On higher levels, the interrelation between features and feature interoperability is captured whereas on lower levels a feature is described in terms of geometric, topological and parametric entities. Different engineering tasks can utilise feature ontologies as a basis for application-specific shape reasoning across several modelling layers

One of the main problems in feature-based modeling is to represent and to handel the feature semantics as well as the geometric and topological information. In this paper an algebraic representation structure which maps feature shape semantics into a geometric model and provides facilities for interactive feature manipulation is presented. In this structure, called the Feature Entitiy Relation Graph (FERG), the parameters defining a form feature are expressed as algebraically formulated relationships between feature entities. In the same way it is possible to represent dimensions and geometric constraints to express the funcitonal shape requirements of the part and to preserve the feature shape semantics. To enable local as well as global interactions and manipulations on FERG, entities and relationships are structured at different levels of detail

Abstract:In this paper the concept of Feature-based Virtual Engineering is presented as an approach to integrated product development. The focus of the paper is on presenting the current state of the development of a feature-based parametric representation for product semantics including a concept for creating and maintaining application specific views on the product information.

No abstract