基于STEP-NC的自由曲面刀具路径生成术的研究

在详细地分析了STEP-NC程序相对于G/M代码差异及优越性的基础上,深入地对基于STEP-NC的CNC系统中关键技术——刀具路径生成技术进行了研究。本文以自由曲面为例,首先分析了自由曲面如何在STEP-NC程序的表述,然后从STEP-NC程序中提取有用的信息自动生成刀具路径,最后采用仿真来验证该方法的正确性。     

基于STEP-NC数控加工的研究

STEP-NC技术是STEP标准在制造领域的应用，它定义了一种新的数控程序标准。首先介绍了STEP—NC的概念、数据模型和文件格式，对STEP-NC控制器进行了研究，提出了STEP—NC控制器应实现的功能和框架结构。探讨了STEP—NC的出现对制造信息化的影响，提出了基于STEP—NC的制造系统的闭环模式，研究了基于STEP—NC的智能化、网络化的实现方法，最后对其发展进行了展望。     

基于STEP-NC切入方式下高速铣削刀轨研究

根据STEP—NC高速铣削的不同切入方式,通过具体铣削过程中的切入角的变化对铣刀所受载荷的影响,进行了高速铣刀的有限元分析,主要解决了型腔和外轮廓周铣刀轨进刀方式的选取,对切入角的寻优自动编程技术的发展有一定的实用性。     

基于STEP-NC的CAD/CAM与CNC系统集成的实现

针对传统数控系统的不足之处,提出了基于STEP-NC实现CAD／CAM系统与CNC系统集成的方案,介绍了STEP-NC的概念、研究状况、ISO14649标准的有关内容以及基于ISO14649标准的数据模型、数控程序,展望了STEP-NC的研究前景及面临的挑战。     

基于STEP-NC的CNC系统中插补技术研究

STEP-NC是一个新的数控编程接口,基于STEP-NC的CNC系统是未来数控技术发展方向之一.在该系统中不但具有直线和圆弧插补功能,而且还具有样条曲线插补功能.开发了一个统一的 基于NURBS样条曲线插补的通用插补器,推导出一个简洁的NURBS几何数据预处理算法,详细论述了基于等弧长的插补技术和插补原理.最后,通过仿真和实例加工验证了上述算法的有效性和可靠性.     

基于STEP-NC和XML的CAD/CAM/CNC集成技术

基于STEP-NC标准,将设计与制造模型统筹考虑,研究产品从设计到制造整个生命周期内的数据共享与信息集 成技术。应用XML实现产品信息的网上传递,从而实现网络环境下CAD/CAM/CNC的双向无缝集成。     

面向STEP-NC的数据处理与仿真平台研发

介绍了STEP-NC数据模型的基本特点，分析了数控程序中的信息类型，研究了从STEP-NC文件中直接提取制造信息的基本方法，建立了基于特征的数控加工几何仿真模型，并讨论了相应的实现方法和技术。最后在ST-Developer环境下开发了一个基本的STEP-NC支持平台，其基本功能包括STEP-NC文件的翻译、制造信息的提取、组织和图形化显示等，并能以工步为单位进行仿真。     

STEP-NC compliant process planning as an enabler for adaptive global manufacturing

Manufacturing firms are seeking more efficient methods of CNC manufacture. ISO14649 informally known as STEP-NC has been proposed as a high-level hierarchical manufacturing information model as a replacement for the low-level machining instructions of ISO6983 and RS274D. In this paper, the applicability of STEP-NC as an enabler for creating an adaptive global manufacturing system is examined. The overall framework of the system is presented followed by an outline of its information requirements. Suitability of STEP-NC to support each requirement is then studied with the necessary additions highlighted. Finally, a test component is used in conjunction with a prototype of the advanced global manufacturing system to demonstrate the applicability of the STEP-NC standard to support manufacturing information in such a system.     

Realization of STEP-NC enabled machining

A STEP-compliant CNC machine tool that demonstrated a G-code free machining scenario is presented. The aim of this research is to showcase the advantages of, and evaluate, STEP-NC—a new NC data model—by implementing it in a legacy CNC system. The work consists of two parts: retrofitting an existing CNC machine and the development of a STEP-compliant NC Converter called STEPcNC. The CompuCam's motion control system is used for retrofitting the machine, which is programmable using its own motion control language—6K Motion Control language and capable of interfacing with other CAPP/CAM programs through languages such as Visual Basic, Visual C++ and Delphi. STEPcNC can understand and process STEP-NC codes, and interface with the CNC controller through a Human Machine Interface. It makes use of STEP-NC information such as “Workplan”, “Workingstep”, machining strategy, machining features and cutting tools that is present in a STEP-NC file. Hence, the system is truly feature-based. The Application Interpreted Model of STEP-NC has been used.     

Process control in CNC manufacturing for discrete components: A STEP-NC compliant framework

With today's highly competitive global manufacturing marketplace, the pressure for right-first-time manufacture has never been so high. New emerging data standards combined with machine data collection methods, such as in-process verification lead the way to a complete paradigm shift from the traditional manufacturing and inspection to intelligent networked process control. Low-level G and M codes offer very limited information on machine capabilities or work piece characteristics which consequently, results in no information being available on manufacturing processes, inspection plans and work piece attributes in terms of tolerances, etc. and design features to computer numerically controlled (CNC) machines. One solution to the aforementioned problems is using STEP-NC (ISO 14649) suite of standards, which aim to provide higher-level information for process control. In this paper, the authors provide a definition for process control in CNC manufacturing and identify the challenges in achieving process control in current CNC manufacturing scenario. The paper then introduces a STEP-compliant framework that makes use of self-learning algorithms that enable the manufacturing system to learn from previous data and results in eliminating the errors and consistently producing quality products. The framework relies on knowledge discovery methods such as data mining encapsulated in a process analyser to derive rules for corrective measures to control the manufacturing process. The design for the knowledge-based process analyser and the various process control mechanisms conclude the paper.