基于STEP-NC车削仿真的关键技术探讨

基于STEP-NC的智能化数控系统开发的一部分,以车削仿真为研究对象,重点探讨了STEP-NC车削数控系统中仿真模块实现的几个关键技术,为STEP-NC车削数控系统智能化的实现提供了一定的理论依据.     

网络化制造中基于STEP-NC的编程方法

STEP-NC是由欧美提出的新的数控接口标准，目的是取代旧的数控标准ISO6983。本文首先分析了STEP-NC的两种应用标准：ISO14649（ARM）和STEPAP238（AIM），并且分析了Part21和Part28的应用领域及Part21文件格式和其中的信息产生方法。然後介绍了ST-Developer环境下ROSEC＋＋颠库编程接口及其应用程序的早、晚编联方式，并且以此为基础设计了整个程序的编程流程，重点介绍了工艺规划设计。最后给出了在C＋＋编程环境下利用ROSE库函数写入形成STEP AP238文件的方法。     

工作流仿真平台的设计与实现

讨论了工作流管理技术,提出了工作流仿真的概念,介绍了一种工作流系统仿真平台的设计与实现。     

面向方框图仿真的模型建立与仿真计算

在对高阶系统及非线性系统进行仿真时，需要求解高阶微分方程与非线性微分方程。当中的变量耦合问题较难处理，面向方框图仿真方法可以较好地解决这个问题，仿真计算简单，界面直观，对控制系统的设计起较好的辅助作用。主要介绍面向方框图的仿真模型的建立方法，讨论线性及非线性微分方程的方框图模型，并简单介绍面向方框图的仿真计算和误差分析。     

计算机仿真产品设计与制造的实现

本文以微机为开发平台，以ＡｕｔｏＣＡＤ为支撑软件，针对ＡｕｔｏＣＡＤ软件的欠缺之处，通过增加矢量化，渲染模块待工作以完成计算机仿真产品的设计与制造过程。     

基于线程技术的数控仿真控制

数控仿真是一个耗时的过程，因此有必要对其进行控制。本文给出了采用线程技术来实现仿真控制的方法，包括改变仿真过程的状态，高运行速度和视角范围等等，该方法稳定可靠且易于实现。本文最后分析了在数控仿真控制中，这种技术受到的限制。     

CAM自带仿真模块与VERICUT仿真对比与综合运用

对CAM自带仿真模块与VERICUT仿真情况进行对比,以加工腔体零件前罩为例,从图形显示、干涉检查、程序的显示验证、尺寸检验以及程序优化等方面进行了对比,并分析了两类机械加工仿真模式的优劣,为不同需求的工程技术人员提供了仿真方法的借鉴和参考.为了更好的利用两类仿真软件,提出把两类仿真软件结合使用,并结合PDM工作环境,对CAM软件和第三方仿真软件的优势进行了整合,建立了全新生产准备模式下的信息模型,提出了新的新的生产准备方式.     

面向控制系统方框图的仿真软件包

介绍了控制系统方框图形式化描述和根据方框图对系统进行仿真的原理和算法。面向控制系统方框图的仿真软件包SYSTBM BUILDER集成了丰富的系统开发工具,能有效地辅助设计人员进行控制系统的设计、仿真、优化和编程,可对线性系统和非线性系统进行计算机数字仿真。     

面向对象通用仿真平台的研究

本文介绍一种面向对象通用仿真平台的设计思想及核心技术。     

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.     

基于STEP-NC的数控系统体系结构的研究

分析了当前主流开放式数控系统的本构模型,建立了系统内部的信息流模型,根据非实时、弱实时和强实时区分信息流。综合考虑数控系统的功能模型、信息流模型,建立STEP-NC数控系统的层次模型为模型应用层、制造规划层和实时控制层。给出了基于PC和嵌入式系统分层架构的STEP-NC数控系统结构。     

Modelling and implementing circular sawblade stone cutting processes in STEP-NC

The paper presents a STEP-NC compliant implementation of circular sawblade stone cutting machining processes. Although some stone machining processes has been already covered in the STEP-NC research and standardization initiatives (as for instance stone machining through stone milling machines), there have not been yet, however, any detailed model proposal to cover circular sawblade stone cutting operations. Sawblade cutting technology for stone parts have several specific parameters with no clear equivalent technologies as defined in milling, turning, etc. The paper reviews main characteristics of the circular sawblade stone cutting machining operations, and proposes a STEP-NC extended model based on the selection and definition of new features and on the modelling of these stone cutting operations. The resulting model is the base for the development of the STEP-NC stone cutting CAM and CNC machine. The machine architecture is designed to be able to react to changes in the machining conditions, very common in this technology. The system is based on the definition of features to be communicated to the controller. The controller has the objective of machining the features, and it is able to re planning, on real time, the work to get them despite changing conditions in the stone or in the disc.     

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.     

多模复合制导数据处理仿真平台的研究

随着数据融合技术的发展,相应的理论及算法越来越多。多模复合制导数据处理系统可以看作多变量控制复杂系统,其设计、实现与评估变得更加困难。该文介绍了多模复合制导数据处理仿真平台。该平台通过简化导弹的分解模型,对复合制导系统进行功能模块化分解,引入工具箱式的复合制导流程体系和复杂战场环境的仿真实现对多模复合制导数据处理系统的仿真、算法的开发和验证。最后以某型反辐射导弹复合制导数据处理器的研制过程为例简介了其典型应用。     

STEP-NC compliant approach for setup planning problem on multiple fixture pallets

Manufacturing system configuration is a broad problem that involves various topics concerning workpiece, cutters, fixture and machine. This paper presents an approach to solve the setup planning problem on machining centres based on a STEP-NC compliant data structure. The aim of this approach is to shorten the time required for the process planning activity by automating some time-consuming steps without compromising the solution accuracy. In the proposed approach, a CAM software tool is employed to associate the geometric and technological data regarding the product. Using the proposed data structure, a method is proposed for solving the setup planning problem based on mathematical programming. The developed approach has been tested on a real case.     

基于XML的STEP-NC程序解释器的设计与实现

通过分析STEP-NC数据模型及程序结构,指出ISO10303 Part21物理文件格式数控程序不适合在网络上传输的缺点.因而在对现有数控系统进行基于STEP-NC的改造时,采用XML作为STEP-NC数控程序的文件格式,并提出面向网络化制造STEP-NC数控系统的基本框架,阐述了各组成模块的功能.同时从教据存储结构、解析XML、信息提取方法三个方面重点介绍基于XML的STEP-NC程序解释器的设计.最后采用JAVA语言实现了该解释器的功能,并通过STEP.NC标准草案里的一个实例验证该设计的正确性.     

数控加工模拟实验台的系统软件设计

本文从CNC系统软件的特点入手,论述了在VisualC 6.0的环境下开发数控加工模拟实验系统软件各模块的过程。     

A Unified Manufacturing Resource Model for representing CNC machining systems

Standard information representation in the manufacturing business has always focused on products with information relating to their design, geometry and required processes. However there is no standardized information model available to represent the manufacturing equipment used to produce such products. This equipment contributes as a significant investment in setting up a CNC manufacturing facility and is considered as a major asset of the business. Thus the authors see a need for an effective model to represent such equipment particularly the most expensive assets namely CNC machining systems. Such a model could represent the machine resource and also its additional auxiliary devices such as workpiece and cutting tool changing mechanisms, bar feeders, pallet/gantry systems and robotic arms. These devices can function with a CNC only when the controller's resource data model can represent their functionality. Currently every machine tool and auxiliary device manufacturer promotes their own resource data models; resulting in a plethora of representation methods which are bespoke and incomplete in terms of representing the entire system's resources. This paper proposes a Unified Manufacturing Resource Model termed UMRM. UMRM not only has the novel capability to provide the information to define the various elements of the CNC machining system, but also has the added capability to provide support for automation of process planning decision making.