远程监控设备与Lon智能节点开发

该文论述一种基于Internet的远程设备监控系统结构及其设备开发技术,并通过一个无级调光设备节点的设计阐明设计过程以及各软件层次部分程序代码。实验说明该系统具有良好的网络实时性和控制有效性,对研究网络控制系统实施方案具有重要意义。     

虚拟车间三维仿真环境的构建技术

该文在虚拟制造的环境下,对虚拟车间的制造资源进行了三维建模,并对这些资源如何支持NC代码的加工进行了研究分析,为实现基于多智能体的虚拟车间敏捷调度提供了三维仿真的支撑环境。     

STEP-NC based high-level machining simulations integrated with CAD/CAPP/CAM

With the development of manufacturing,numerical control(NC) machining simulation has become a modern tool to obtain safe and reliable machining operations.Although some research and commercial software about NC machining simulations is available,most of them is oriented for G&M code.It is a low-level data model for computer numerical control(CNC),which has inherent drawbacks such as incomplete data and lack of accuracy.These limitations hinder the development of a real simulation system.Whereas,standard for the exchange of product data-compliant numerical control(STEP-NC) is a new and high-level data model for CNC.It provides rich information for CNC machine tools,which creates the condition for an informative and real simulation.Therefore,this paper proposes STEP-NC based high-level NC machining simulations solution integrated with computer-aided design/computeraided process planning/computer-aided manufacturing(CAD/CAPP/CAM).It turned out that the research provides a better informed simulation environment and promotes the development of modern manufacturing.     

三维虚拟加工环境及其关键技术的研究

在分析虚拟制造特点的基础上,提出了三维可视化虚拟加工环境的系统结构,介绍了支持三维建模仿真的组件设计、基于装配模型的三维实体建模方法、NC代码解析器的设计方案以及基于毛坯表面三角片离散化的加工过程仿真算法,并开发了虚拟加工环境原型系统,该系统能够实时地反映零件虚拟原型的加工成形过程仿真,并进行可加工性分析。     

远程数控仿真系统的设计与实现

由于几何建模的复杂性和消隐算法的低效性,目前的数控仿真系统大多只能实现数控加工结果显示,而在数控加工过程实时仿真方面功能还很弱,对于基于Internet的远程数控仿真的研究则更少。为解决以上问题,提出了实现远程数控仿真的技术框架,即采用VRML建立几何模型,采用Java建立通信接口,构造虚拟环境与操作者之间的通信机制。通过构造EAI接口控制Eleva-tion Grid结点,实现工件动态建模,采用Java applet构造NC代码解释器,并阐述了干涉校验的实现方法。实现了远程数控仿真系统。     

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。     

An integrated manufacturing planning assistant — IMPA

In this paper, we describe our development of a fully integrated manufacturing planning assistant (IMPA) system, which is able to: (1) interpret the finished part requirements directly from the designer's CAD systems or solid modelers without user intervention or special feature coding; (2) check the machinability of a designed part; (3) automatically generate a process plan, a tool path and an NC (numerically controlled) code, and (4) support interactive user modification of the resulting plans, tool paths and NC code. A demonstration version of the system was designed to provide automated assistance for the planning of machining processes on three-axes NC machine tools. The underlying architectural concepts and reasoning algorithms can be extended to more complex machines such as four-or-more-axes NC machines. CAD, CAE, and CAM including robotic, FMS (flexible manufacturing system) and NC machines are widely used in industry today. There is increasing interest in automation of factory control software Merchant, (1988); this includes automating the generation of the control programs — that is, in developing systems which will automatically produce the NC code for machining the part, given a model of the part, the shape of the raw material, and the machine specifications. With such systems, there are several difficulties in the manual preparation of an NC program code such as, long and tedious calculations, high risk of error in data preparation, etc., which need to be eliminated. This is a critical step toward the integration of CAD and CAM into a truly concurrent engineering and manufacturing environment.     

机械加工MBD毛坯模型的特征识别设计方法

为了解决基于模型的定义(MBD)环境下机械加工毛坯辅助设计问题,采用特征识别技术辅助创建三维毛坯模型.首先分析了机械加工工艺设计环节MBD毛坯模型的组成要素与模型要求,并建立零件模型的属性面邻接图;根据零件模型上加工特征的特点划分简单特征、体积特征和表面特征;通过属性面邻接子图的模式从特征集合中识别出简单特征与体积特征,并利用补特征法与半空间法抑制这2种特征;最后,根据工艺员输入的表面加工余量创建抑制表面特征的实体.在整个毛坯设计推理过程中研究了三维制造标注的维护方法,最终达到辅助工艺员快速设计MBD毛坯模型的目的.     

复杂零件数控加工的仿真与优化研究

复杂零件数控代码繁多,采用人工检测、试切和机床运行的代码检测方法将造成极大的资源浪费。为了减小这方面的浪费及提高复杂零件加工的质量,本文以减速器中的典型零件产品为例,在Vericut里面建立三轴加工环境及方针模型,对数控代码进行仿真。通过仿真,优化了数控代码,精确模拟出实际的加工过程,直观地观察到刀具的轨迹和工艺的可加工性,为复杂零件的高效数控加工提供了借鉴。     

CAXA在数控技术中的编程理论

本文通过阐述CAXA在数控技术中的编程理论,详细说明了用CAXA制造工程师实现数控加工的过程,并论述了数字化制造所特有的优越性,并为数控技术中的CAXA只要工程师在数字化制造过程提供了理论依据。     

Dimensional and geometrical errors of three-axis CNC milling machines in a virtual machining system

Virtual machining systems are applying computers and different types of software in manufacturing and production in order to simulate and model errors of real environment in virtual reality systems. Many errors of CNC machine tools have an effect on the accuracy and repeatability of part manufacturing. Some of these errors can be reduced by controlling the machining process and environmental parameters. However geometrical errors which have a big portion of total error need more attention. In this paper a virtual machining system which simulates the dimensional and geometrical errors of real three-axis milling machining operations is described. The system can read the machining codes of parts and enforce 21 errors associated with linear and rotational motion axes in order to generate new codes to represent the actual machining operation. In order to validate the system free form profiles and surfaces of virtual and real machined parts are compared in order to present the reliability and accuracy of the software.     

A feature-based method for NC machining time estimation

Machining time estimation plays an important role in manufacturing process planning and scheduling. Existing NC machining time estimation methods are all based on material removal rates, NC programs, and machine characteristics. However, the machining condition which is related to the geometry-process information is also an important impact factor of the NC machining time estimation. As existing methods cannot satisfy the requirement of timeliness, accuracy and efficiency, this paper presents a feature-based method for NC machining time estimation. Experiment results show that the proposed approach is feasible and practical. It is particularly useful in real time manufacturing process planning and scheduling systems.     

A novel methodology for cross-technology interoperability in CNC machining

In CNC part programmes, the lack of standardisation for representing part geometry and semantics of manufacturing operations leads to the necessity for existence of a unique part programme for each machine. Generating multiple programmes for producing the same part is not a value adding activity and is very time consuming. This wasteful activity can be eliminated if users are given the ability to write an NC program for a specific machine and robustly convert the program to syntax suitable for another CNC machine with a different structure. This, cross-technology interoperability, would enable for parts manufactured on old CNC machines using legacy code to be manufactured on new CNC machines by automatically converting the programmes. Every NC programme is written based on various categories of information such as: cutting tool specifications, process planning knowledge and machine tool information. This paper presents an approach for cross-technology interoperability by refining high-level process information (i.e., geometric features on the part and embedded manufacturing resource data) from NC programmes. These refined items of information stored in compliance with the ISO14649 (STEP-NC) standard may then be combined with new manufacturing resource information to generate NC code in a format that is compatible with machines based on different technologies. The authors provide a framework for this process of identification, semantic interpretation and re-integration of information. The focus of this paper is on asymmetric rotational components as the initial application area. To demonstrate the proposed cross-technology interoperability approach, a C-axis CNC turn–mill machine and a 4 axis CNC machining centre have been used with a simple test component.     

虚拟加工中NC代码转化技术研究

在虚拟加工过程中，虚拟机床是由刀位文件驱动而工作的，为了使虚拟加工环境具有接收和检验NC代码的功能，需要将NC代码翻译成刀位文件。该文在对NC代码翻译成刀位文件的可行性进行研究后，开发出了NC翻译器。翻译器共分以下几个模块：文件的读入与存储、错误分析与语义分析、翻译执行、数据轨迹仿真等。最后并给出了槽型凸轮的NC代码的翻译实例验证，以及翻译后的刀位文件的虚拟加工结果。     

基于嵌入式Linux的机房远程监测系统研究

为满足机房实时监测环境参数和视频信息的需要,本文综合运用嵌入式技术、WEB技术和信息检测技术,研究并设计一种基于B/S架构的嵌入式机房远程监测系统。通过传感器采集并远程传输机房温度和图像数据,在远程浏览器端动态实时显示,为及时掌握机房环境数据,实现机房科学管理提供良好的平台。     

A multi-regional computation scheme in an AR-assisted in situ CNC simulation environment

Computer numerical control (CNC) simulation systems based on 3D graphics have been well researched and developed for NC tool path verification and optimization. Although widely used in the manufacturing industries, these CNC simulation systems are usually software-centric rather than machine tool-centric. The user has to adjust himself from the 3D graphic environment to the real machining environment. Augmented reality (AR) is a technology that supplements a real world with virtual information, where virtual information is augmented on to real objects. This paper builds on previous works of integrating the AR technology with a CNC machining environment using tracking and registration methodologies, with an emphasis on in situ simulation. Specifically configured for a 3-axis CNC machine, a multi-regional computation scheme is proposed to render a cutting simulation between a real cutter and a virtual workpiece, which can be conducted in situ to provide the machinist with a familiar and comprehensive environment. A hybrid tracking method and an NC code-adaptive cutter registration method are proposed and validated with experimental results. The experiments conducted show that this in situ simulation system can enhance the operator’s understanding and inspection of the machining process as the simulations are performed on real machines. The potential application of the proposed system is in training and machining simulation before performing actual machining operations.     

加工特征排序及NC代码映射

在零件的加工过程中,特征的消亡(主要指余量)和实现(主要指尺寸、精度)必须按一定的顺序进行.因此,研究了加工特征的排序机理,提出了一种基于知识的加工特征自动排序方法.在此基础上进一步提出了刀具路径和NC代码的自动生成方法.     

中药滴丸制剂过程监控系统设计与实现

以中药滴丸制剂过程数字化改造为背景，介绍了滴丸制剂过程监控系统的设计与实现。系统采用PLC与工控机组网的方式构建DCS实现对制剂过程的监测控制，并在DCS的基础上构建基于B／S模式的远程访问平台，以实现制剂过程的远程监测。     

网络化产品协同设计的理论与实践

网络化产品协同设计是实施先进制造的重要支撑技术,该文在分析其研究现状和特点的基础上,提出了基于中介代理的联邦式协同机制和基于约束松弛的协同递归式设计模式,为分布式协同设计的有效运作和基于知识的协同求解提供了一种理论依据。设计并开发了相应的网络化协同设计支持系统——CoDesignSpace,给出了系统的体系结构和实施方法。     

基于Jini支持X3D的虚拟场景浏览器的研究与探索

随着计算机技术和网络技术的不断发展,为了使多个用户在一个基于网络的计算机集合中,共享同一个虚拟环境,从而设计在一个分布式虚拟环境中。支持多用户共享的具有独立功能的虚拟环境浏览器成为必然。而当前虚拟场景的浏览器大多是设计为IE或Netscape等浏览器的一个插件,而不是一个独立的客户端。随着基于Java的分布式计算平台Jini和面向下一代的三维图形标准X3D的发展,为研究支持分布式虚拟环境的浏览器提供了理论基础。该文在讨论X3D和Jini技术的基础上。实现了一个基于Jini支持X3D的虚拟场景浏览器的简单原型。