Research on the Conversion from Design Features to Machining Features Faced on STEP-NC

STEP-NC is considered as a replacement of G-Code and an enhancement to STEP. STEP-NC provides not only a full description of a part, but the machining process of each designing feature with machining information. In order to meet the requirements of STEP-NC and integrate with CAD/CAPP/CAM, a new methodology for converting design features of a feature-based design part model into machining features is presented in this paper. By touring the features´ trees, judging the features´ relationships and querying the features´ surfaces, the features attribute adjacency graph are constructed, the machining features are obtained by matching boundary patterns in the local feature area, then the related machining information, such as the machined area, the avoided area and the tool approach direction is extracted. Finally, a case study is used to illustrate the validity of the proposed conversion algorithm directly from design features to machining features coming from CAD part models in STEP neutral format.