The Study On Developing Platform Of Radan CAD/CAM Post Processor

Post processor may be the bridge between CAD/CAM systems and NC machine tools and may play the key role in transforming the machining data generated from CAD/CAM software to the NC codes of NC machine tool.At present,the most of post processors are supplied by software developer or to be written by some special programmer.A developing platform special for Radan CAD/CAM post processor is presented in this paper based on the sturcutral features of Radan post processors,which is special for users with little knowledge of program grammer of the post processor to be able to develop new post processorbythemselves.Based on the structure features and variation rules of Radan post processor,a synthetical reasoning method is put forward which combines the methods of CASE and production rule.The post processor developing platform may consist of a post processor casetemplate library,the knowledge base,the reasoning machine,and the man-machine interface.The program blocks such as NC code definitions and their variable assignment are expressed to be the knowledge of the system.The platform can select template with relative conditions and infer the defined NC codes,parameters and modes automatically to enerate the required post processor.In order to fit the best case template,a similarity algorithm of the edit distance is introduced,which will reduce the workload for developing a post processor greatly.The production rule is used for knowledge representation.To ensure the consistency and correctness of new knowledge,the grammar and validation of the new added Knowledge is detected by the system.The classification code is used in the rule based inference to decide the category of NC code.The inference engine only needs to match the rules of this category.The inferring results will be sorted with their priority.The system was developed in VS2013 environment and Access is used for the database.Practice shows the system can genrate some post processors in some range of variation without special requirement for users in their basis knowledge in the structure and grammer of the post processors.For few special post processors,the system will allow users to modify the program interactively.Meanwhile,the system will assist user to check the new knowledge in its grammer and finish the learning process of the new knowledge.