Research On Freeform Feature Reconstruction In Semantic Feature Modeling

Feature modeling is one of important techniques in integrated system of CAD or CAM, which is a key to product modeling. The integral model of product information based on feature should be built, which can solve data exchanging and data sharing in the process of designing, production, quality-controlling, and organization-management. At the same time, the parametric design technique is applied to feature-based design system, where the feature can be adjusted, which improves the efficiency of designing process. So, the parametric design technique based on feature has become very important in most CAID systems.The current feature modeling systems are all based on the history, in the process of product design and later modification, the time of reconstructing new geometric model will increase linearly along with increase of model complexity, so the efficiency of model reconstruction is low. And the current feature modeling technologies are mostly based on the regular-shape features. With the development of feature modeling technologies, more and more freeform features are involved, this question needs to be solved timely.In order to maintain the intent of designers and satisfy them, this paper discusses freeform feature reconstruction in semantic feature modeling. With the study of HUST-CAID system (Computer Aided Industry Design System developed by Harbin University of Science and Technology), freeform feature is introduced in HUST-CAID aims at the shape domain limits to the prismatic and cylindrical shapes in most feature modeling systems. Classification of freeform features is defined according to the characteristics of HUST-CAID. In order to reduce the redundant data in models and improve the efficiency of model design, this paper proposes a scheme to compress and simplify the freeform features.