Research On Manufacturing Feature Recognition Based On Model Definition

Manufacturing data,the rapid development of intelligent level to the computer integrated system put forward higher requirements,data exchange and sharing become more frequent.The effective integration of CAD/CAPP/CAM system is the core module of computer integrated system,and one of the biggest problems in CAD/CAM integration is the lack of intelligent interface between CAD/CAPP.Feature recognition technology is an effective way to solve this problem.Feature recognition technology through the CAD model of the characteristics of information,the establishment of information model,CAPP system directly from the model to obtain manufacturing information.In this paper,combined with MBD model in the three-dimensional environment,the study of mechanical parts model manufacturing characteristics of the identification method,aiming at the problem that intersecting feature is difficult to identify,a hybrid recognition method is proposed to complete the separation and subgraph matching of general intersecting feature,and UG secondary development technology is used to realize the recognition algorithm.The main contents are the following aspects:The establishment of predefined feature library.According to the characteristics of feature matching in feature recognition,combined with the characteristics of research model,we use Visual C ++ or Microsoft Visual Studio 2010 to support C language programming platform,UGNX,NXOpen and other tools to establish a model feature library for matching.The basic feature of the model is built by the addition of the block function in the modeling software.On the other hand,the relationship between the feature elements and the topology information in the modeling process is characterized by the basic characteristics of the model Identify the provisioning data source.Analysis of MBD model information acquisition.This paper studies the creation of the Model Based on the Model Based on the MBD(Model Based Definition),and completes the annotation of the dimension information,tolerance information and annotation information.Based on the data characteristics of MBD model,the method of feature information extraction is analyzed.A method of recognizing intersecting features based on graph expansion and traces is proposed.Through the study of the feature recognition of typical parts,the author summarizes the attribute adjacent map creation and separation process,analyzes the simple intersecting feature type,combines the general characteristic recognition process,prepares the CAD model to be preprocessed to establish the processing plane attribute And the edges of the machining plane attribute are adjacent to each other in the figure as the sign of the existence of the intersecting feature.The concept of the preferred feature surface is proposed and the addition of the virtual link is completed by using the preferred feature surface and the specific feature traces.And the establishment of the basic characteristic subgraphs under the guidance of the comprehensive judgment factor.By adding the normal vector attribute relations between all the feature planes to the feature subgraphs,the attribute graphs are obtained by the local attribute graphs.And finally the adjacency matrix of the extended subgraph is used to complete the matching with the predefined basic features,and the identification of the feature type is realized,and the recognition of the intersecting feature is completed.Complete the validation of the recognition algorithm.The UG secondary development technology is used to realize the feature automatic recognition function and feature information extraction.The feasibility of the development function is verified by an example.