STEP-NC的可扩展标记语言实现方法研究

STEP-NC是新发展的数控编程国际标准（ISO14649），依据该标准生成的数控程序通常采用ISO10303 Part21物理文件格式。但该格式的数控程序不但不易解释，而且不适合在网上传输。为此，提出了采用可扩展标记语言作为STEP-NC数控程序的文件格式。首先，分析了STEP-NC数据模型核心内容及ISO10303 Part21物理文件格式数控程序的缺点，研究了可扩展标记语言格式STEP-NC数控程序的生成，包括文档结构的选择、EXPRESS向可扩展标记语言的映射等，并将其作为机床控制器的输入。将机床控制器软件划分为3个模块，即可扩展标记语言形式数控程序的解释、微观工艺规划并自动生成刀具路径和控制机床运动的数控指令的生成。重点研究了可扩展标记语言数控程序的解释。

XML implementation of STEP-NC data model

STEP-NC is a newly developed international standard(ISO 14649) for Numerical Control(NC) programming,and ISO 10303 Part 21 physical file is the common format of NC program generated through the STEP-NC standard.However,the file format is not easy for interpretation and transferring information over World Wide Web. To deal with this problem,the method of adopting eXtensible Markup Language(XML) as file format of NC program was proposed.Key concepts of STEP-NC data model and shortcomings of STEP-NC numerical control program in the Part 21 physical file format were analyzed.Then how to generate the NC program of XML file format was studied including selecting file structure,mapping from EXPRESS to XML.Next,the XML file was used as the input of CNC controller.Software of CNC controller was divided into three modules,namely interpretation of NC program in XML,micro process planning and automatic generation of tool path,and generation of NC instructions for Machine Tool Motion.For the three modules,the first one was studied in particular.