| Current solid modeling CAD systems are geometry based, and the entity types that are supported are at a low level, e.g. points, lines, arcs, etc. Some efforts have been made to derive higher level entities such as features from lower level entities, but success has been limited. Information regarding tolerances and other fundamental attributes used to describe mechanical parts are not associated with the part features in the solid modeler database. A feature based design system can incorporate these attributes. Also, a feature based design system may be made more supportive of the design process. This paper describes a prototype feature based design system for turned parts. The prototype system allows the user to design mechanical parts using features and provides intelligent design aids like automatically specifying size tolerance according to mating conditions, and performing redundant location dimension and tolerance checking. The meaning of the design data is captured so that it can be manipulated by intelligent application software. |
