Research And Implementation Of Complicated Machining Features Recognition Technology For The Aircraft Structural Parts

This work is supported by the National Natural Science Foundation of China, National S&T Major Project, and aircraft manufacturing corporation. The paper makes further study into the key technology of the complicated machining feature recognition of the aircraft structural parts according to the recognition difficulties in variable topology, freeform surfaces, and feature interaction. The main job of this paper are as followed:1) A blend feature recognition and suppression method is studied. The method gets the parameter estimation of freeform surfaces and recognizes the blend feature. It deletes corresponding faces and edges in the AAG. It realizes suppression of the blend feature without changing the solid model.2) Presents a new method of recognizing complicated features with variable topology. A layer-based recognition methodology is presented. Analyze on features of aircraft structural parts shows the characteristics of variable topology with directional characteristics and hierarchy distribution. The method deals with features with variable topology, recognizes interacting features by combining layers and generates reasonable feature interpretations according to the association between layers.3) A new method of feature interactive recognition is studied. The method concludes and summarizes the problem in automatic feature recognition. The influence factors of recognition reliability and their corresponding influence value are summarized. It realizes automatic examinations for recognition result and shows the reliability of the result to reduce the examination work.4) The system about feature recognition for complicated machining features of the aircraft structural part is developed, which is applied to an aircraft manufacturing corporation and has been proved effective.