Machining Feature Definition By Users And Recognition Methods For Complex Structural Parts

Supported by the National S&T Major Project, the National Natural Science Foundation of China, and considering the requirements of aerospace industry, in the view of problems that existing machining feature definition is poor in applicability for complex structur al parts, NC machining process planning is difficult for different types of structural parts and process capability, the technology of machining feature definition by users and recognition were deeply studied. The main achievements of this paper are as follows:1) The method of user-defined machining feature for complex structural parts was put forward. After constructing a model of user-defined machining feature, the user-defined machining feature geometric information was described based on adjacency graph and semantic rules, and the definition of standard and method for user-defined machining feature process information were presented, eventually, the machining feature definition by users was realized.2) The recognition method of user-defined machining feature for complex structural parts is studied. For the characteristics that user-defined machining features are of great variety and different, a universal parsing method was presented for extracting user-defined machining feature information, then the mapping mechanism from part model to user-defined machining feature was created, with which the user-defined machining feature recognition for complex structur al parts could be implemented.3) The process planning method of user-defined machining feature for complex structural parts was studied. The correlation between user-defined machining feature geometr ic information and machining process rules was established, then, the mapping from user-defined machining feature geometry to the parameters of machining operation was built based on production rule reasoning.4) According to the above research, a feature-based intelligent programming system for complex structural parts was developed on CATIA V5 platform, which has been successfully deployed in an aviation enterprise,and works well.