【作者】 刘崇；

【导师】 薛开；

【作者基本信息】 哈尔滨工程大学 ， 机械制造及其自动化， 2005， 硕士

【摘要】 STEP-NC(ISO 14649),是由国际标准化组织ISO第184技术委员会第一分技术委员会(ISO/TC184/SC1)为计算机数字控制(CNC)系统制定一种新的数控编程标准。它是STEP标准的扩展,将加工操作组织成系列的加工步骤,每一个操作步骤都能在CNC机床上执行。STEP-Nc中加工步骤就相当于传统G,M代码一样代表就是加工指令。然而不同于G,M代码的是,STEP-NC中的加工步骤所包含的是三维几何信息,刀具需求,特征定义等信息,机床则根据这些可利用资源动态规划加工操作以及智能重组加工操作。 文章开始部分介绍了课题的来源、背景、意义以及STEP-NC标准国内外研究现状,而后通过对STEP-NC的应用活动模型,应用参考模型,应用解释模型的内容的详细介绍,加深大家对STEP-NC数据模型,应用协议(AP238)的范围、应用标准、功能单元,以及其文件结构的了解。 然后在对STEP-NC标准各应用模型进行深入研究的基础上。建立了基于STEP-NC标准的开放式数控后处理解释器。该系统主要分为:EXPRESS解释器,代码提取模块,代码解释模块,基于PMAC的数控指令接口模块。整个系统利用StepTools公司提供的ROSE工具,通过ST—Developer9.0工具中集成的EXPRESS解释器对AP238的应用解释模型进行编译,生成用于操作实体属性的实体类。在对这些实体类进行函数扩展后,来操纵ROSE库中的STEP-NC属性数据。 利用用户扩展的属性处理函数,将实体属性提取出来,作为PMAC数控指令接口模块的输入数据。这些数据通过几口模块的处理根据加工计划按顺序进行刀具路径的规划并将生成的刀具路径生成PMAC指令运动控制程序,最终实现解释STEP—NC代码的功能。更多还原

【Abstract】 STEP-NC(ISO 14649), The data model standard of the computerized numerical control was constituted by ISO/TC184/SC1. STEP-NC is an extension of STEP that organizes manufacturing operations into "work -ing steps. " Each step defines an operation that can be performed on a CNC machine tool. The working steps defined by STEP-NC are roughly equivalent to the machining commands represented by traditional M and G codes. However, unlike M and G codes, the working steps are linked to three-dimensional geometry, tool requirements and feature definitions so that the machine tool can dynamically plan an operation using the available resources and intelligently re-plan an operation when necessary.In the dissertation, we recommending source, background, meaning of the subject and the current studying situation both at home and abroad of STEP-NC standard, and then recommend application activity model, application reference model, application interpret model in detail. Through this we made you can mastered application protocol (AP238 ), using standard .function unit, and its file structure of STEP-NC standard.On the base of researching of the STEP-NC standard, we set up the interpreter model composed of EXPRESS interpreter Code interpret-ter、 Scheduler、 Tool path generator、 Executor and Monitor and CNC system base on PMAC . We realize how to draw process information from STEP-NC file into mid-file and how to draw the data from the database, According to processing method, processing technology, cutter message described in the STEP-NC file, The interpreter create PMAC order to urge the numerical control machine tool processed work-piece.In this dissertation, we start with studying STEP-NC standard and set up the systematic structure model of numerical control based on STEP-NC according to STEP principle and method of standard. Analyzed from technology, we confirm the rational systematic research approach of numerical control with feasible reality and develop the overall scheme. In this way we can develop our own numerical control system based on STEP-NC according to national conditions, which fill the gap that our country is in this domain and narrow the gap with developed country.更多还原