Recognition Algorithm of Complex Machining Features Based on BP Binary Classification Network

Identification of machining features is an important method to realize seamless connection from design to digital processing, and is one of the important guarantees of intelligent manufacturing. It can extract valuable manufacturing semantic information from the geometric topological relationship of solid model and reduce the information loss in the transition from design to processing. However, the existing machining feature recognition methods can not meet the needs of engineering. In order to improve the recognition performance of complex manufacturing features, a novel feature recognition algorithm based on BP binary classification network was proposed. Firstly, a method to identify the component surfaces of machining features in B-Rep model is designed, and the related feature surfaces are combined based on engineering practice. Secondly, the feature coding rules are customized according to the properties of edges from the feature surfaces, and the features are represented as 12-dimensional feature vectors. Then, 6 kinds of multi-BP binary classification networks are designed for 6 kinds of common machining features in milling parts, are trained by self-designed feature data set and obtain the good feature recognition effect. In order to construct a large scale machining feature data set for training, an automatic generation method of feature data set is designed, and the generalized geometric Euler formula is used to verify the validity of the model that automatically generates the feature data set. Finally, based on the concept of ground surface, the intersection features are decomposed into multiple isolated features, and then the network is used to identify the features. The feasibility and effectiveness of this method are verified by an example.