A dynamic feature–based operation planning method for 2.5-axis numerical control machining of complex structural parts

This article presents an operation planning method based on a dynamic feature concept for 2.5-axis numerical control machining of complex aerospace structural parts. A dynamic feature consists of information about the machining effects on the feature between various operations carried out during production. To get the information about the machining effects of a machining operation, non-machining configuration spaces are constructed by detecting the intersection regions within the offset machining boundaries. Each non-machining configuration space refers to the machining effect (either an overcut or undercut). In the proposed operation planning method, dynamic features based on a preliminary process plan are first established. Then, an iterative procedure for adjusting the preliminary machining operations is put forward using updated dynamic feature information with various machining effects transitions and validity constraints during different operations. The method is tested using an aircraft structural part in a feature-based numerical control programming system called FBM_NUAA, which has been used in a large aerospace manufacturing company.