2,5-dimensional Part Feature Recognition And Its Application

Up to now, twenty years for feature research has passed. Feature, which can be sort into design feature, machine feature analyze feature etc. in application point of view, is a bridge between CAD and CAPP, furthermore, it is also a good connecter of geometry topology information of CAD and special engineering information to improve the utility of CAD, CAPP and CAM and to make new sense for part's CAD module, from combination of geometry topology information to special engineering information.Features recognize provides the technology support for the instauration of part's feature module in special domain. However, the technology of applied features recognize is just in laboratory, and many urgent problems is waiting to be solved. This paper starts the deeply research and discuss for features recognize according to the basal idea of features recognize, at the same time, brings forward a new method of features recognize for 2.5D part and a new viewpoint of features mapping. Simultaneity, the arithmetic of tool path generation for machining free-form pockets with islands is introduced, and FreeCAM system for validating the above arithmetic is developed.Firstly, this paper reviews some important methods of features recognize together with their advantage and disadvantage. The essence of features recognize is theoretically analyzed. a new method of features recognize according to the characteristic of 2.5D airplane structure part has been brought forward, it can recognize well hole, pocket, convexity, placket, profile etc. and reduce the space of features recognize and make features recognize efficiently;An idea of features space for recognizing more kinds of features and deepening the theory of features recognize is put forward.Secondly, This paper introduces pocket feature, emphasizes its essentiality in 2.5D part's NC, brings forward a viewpoint of features mapping from produce features to machining features, and the arithmetic of tool path generation for machining free-form pockets with islands.Lastly, this paper makes FreeCAM system based on these above theory for validating the arithmetic of features recognize, features mapping etc.