Evaluation of a feature modelling validation method

Geometric modelling techniques for computer-aided design are provided with formal validation methods to ensure that a valid model is made available to applications such as interference checking. A natural and popular extension to geometric modelling is to group geometric entities into features that provide some extra meaning for one or more aspects of design or manufacture. These extra meanings are typically loosely formulated, in which case it is not possible to validate the feature-based model to ensure that it provides a correct representation for a downstream activity such as process planning. Earlier research established that validation methods can be based on the capture of designers' intents related to functional, relational and volumetric aspects of component geometry. This paper describes how this feature-based validation method has itself been validated through it's application to a series of test parts which have been either drawn from the literature or created to demonstrate particular aspects. It is shown that the prototype system that has been developed is indeed capable of meaningful featurebased model validation and additionally provides extensive information that is potentially useful to a range of engineering analysis activities

Feature modelling: a validation methodology and its evaluation

Geometric modelling techniques for computer-aided design are provided with formal validation methods to ensure that a valid model is made available to applications such as interference checking. A natural and popular extension to geometric modelling is to group geometric entities into features that provide some extra meaning for one or more aspects of design or manufacture. These extra meanings are typically loosely formulated, in which case it is not possible to validate the feature-based model to ensure that it provides a correct representation for a downstream activity such as process planning. This paper presents a methodology used to validate the feature-based representation which is based on the capture of designer’s intents related to functional, relational and volumetric aspects of the component geometry. The feature-based validation method has itself been validated through its application to a series of test parts which have been either drawn from the literature or created to demonstrate particular aspects. It is shown that the prototype system that has been developed is indeed capable of meaningful feature-based model validation and additionally provides extensive information that is potentially useful to a range of engineering and manufacturing analysis activities

Feature-based interaction: an identification and classification methodology

Features are an established means of adding non-geometric information and extra geometric semantics to conventional computer aided design (CAD) systems. For some time it has been realized that, although feature-based modelling is necessary for the next generation of integrated design and manufacturing systems, the inherent feature interactions pose a difficulty in representing and manipulating geometric designs. This paper presents a structured geometric spatial feature interaction identification method based on a broad multilevel classification. Feature interaction definitions and classifications have been surveyed and it is evident that, although many feature interaction classifications have been proposed, there is a lack of a general framework. The classification presented here encompasses existing feature interference cases found in the literature and defines a singular framework that leads to a general classification structure. The framework is presented and applied at three different levels and each interaction case is defined by feature parameters rather than just geometric entities. The restrictions often found in other research concerning contact:non-contact and concave:convex situations are avoided. The resulting classification is easy to understand and implement because it uses simple rules based on commonly available Boolean operators. Finally, an example component is presented and the advantages, uses and applications of the classification scheme are discussed

Feature-based validation reasoning for intent-driven engineering design

Feature based modelling represents the future of CAD systems. However, operations such as modelling and editing can corrupt the validity of a feature-based model representation. Feature interactions are a consequence of feature operations and the existence of a number of features in the same model. Feature interaction affects not only the solid representation of the part, but also the functional intentions embedded within features. A technique is thus required to assess the integrity of a feature-based model from various perspectives, including the functional intentional one, and this technique must take into account the problems brought about by feature interactions and operations. The understanding, reasoning and resolution of invalid feature-based models requires an understanding of the feature interaction phenomena, as well as the characterisation of these functional intentions. A system capable of such assessment is called a feature-based representation validation system. This research studies feature interaction phenomena and feature-based designer's intents as a medium to achieve a feature-based representation validation system. [Continues.