Research On Automatic NC Code Generation System Based On Creo Parametric TOOLKIT

With the comprehensive promotion of the "One Belt and One Road" strategic plan and the "Made in China 2025" plan,it will become an inevitable trend to realize the "digital,information and intelligent" production of the rail vehicle industry.Aiming at the problem of long preparation period of CNC machining EMU,the intelligent code information automatic generation system was developed.Feature recognition and digitization processing of the parts to be processed based on the model definition;measurement points were automatically generated and stored based on automatic measurement and compensation technology;Using the stored parameter information,the machine recognizable processing code instructions was generated by the code automatic generator.The main research work of this thesis is as follows:Firstly,the development design idea was determined and the overall framework of the development system was built,there were three modules in the system:feature recognition and extraction,data storage and code automatic generation,analyzed the entire development system by modular form.Analyzed and discussed the theory of feature classification and recognition,model assembly and parametric drive,template technology,etc.,to ensure the theory and technical support of system development.Secondly,to solve the problem of data acquisition and storage,the theory of coordinate system positive and inverse transformation was studied,the ergodic process and information acquisition process of feature recognition and extraction were written in the structure pattern expressed by B-Rep and using the underlying access functions provided in the Creo Parametric TOOLKIT based on the feature classification and modeling method analysis of side wall and underframe manufacturing,feature recognition and module extraction functions was exploited and implemented based on the Visual Studio 2012 development environment.Designed SQLite database storage system,that the model,parameters,code and other data classification storage table were write,and expressed the relationship between the data tables by using the form of E-R diagram;developed the feature re-display application based on parameters to ensure the high efficiency of finding features by parameters.Thirdly,the application of measurement and compensation technology in practical production was studied.In order to reduce the time and difficulty of writing numerical control code manually,automatic measurement and compensation application suitable for typical manufacturing characteristics was designed and developed based on renishaw measurement technology.By referring to and improving Free Marker template engine,the core part of automatic generation of NC code was constructed,and the replacement of the EL expression in the code template was replaced by the parameters in the storage library to realize the automation function;based on the dynamic programming algorithm and traveling salesman problem,the processing optimization strategy for large multi-manufacturing feature blanks was studied.Finally,took a car body chassis chute as an example,the operation flow of the system was described,and the recognition and extraction of the model features,the storage and return of data and the automatic generation of the final code were successfully realized.The cutting path of the output code was verified by the simulation function of VERICUT.