An Evolutionary Strategy for Free Form Feature Identification in 3D CAD Models

Abstract

Nowadays, most 3D CAD systems support the use of form features. The main advantage of form features is that they provide parametric, high-level support for shape manipulation. When the parametric information of a shape is not available, it can be retrieved using a feature recognition procedure. In this procedure, a target shape is recognized as an instance of one or more features in a pre-defined feature library. The speed and accuracy of the feature recognition procedure significantly improve when the target feature type is known. This information can be provided by a user, but we propose a new method that identifies the feature type automatically. This method uses an evolutionary algorithm to find the optimal feature type. The algorithm randomly generates a population of instances of every type of feature available in the feature library. From this initial population of feature instances, successive populations are generated using the principle of natural selection. The algorithm was tested for different settings and was found to correctly identify features in between one and three minutes.