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.