A web-based virtual system for turn-milling center

This paper presents a three-dimensional, web-based, interactive simulation system for turn-milling center. To overcome the disadvantages of transferring files over the Internet and depending on expensive computer-aided design (CAD)/computer-aided manufacturing (CAM) softwares, the system is developed by virtual reality modeling language (VRML)/JavaScript interaction. The system files produced by machining simulation have small size, and could be transmitted on the web easily. Firstly, a dynamic interactive technology based on VRML and JavaScript, which is essential to a web-based simulation system, has been presented in this paper. Secondly, the geometric and kinematic model is created for representing the turn-milling center motion. Then, the key technologies for machining simulation including material removal, NC codes compiling and collision detection are studied. Finally, to validate feasibility of the proposed system, the virtual machining process for a stepped shaft in the machine tool is carried out. Since the system realizes multiple dynamic demonstrations of virtual machine tool, users can comprehensively understand the product performance. The research for the web-based virtual system of turn-milling center has important research value and application prospect.     

基于VRML-Java3D的交互式装配可视化环境构建

为了实现基于网络的可视化虚拟装配环境,笔者研究了Java3D与VRML相结合的方法。通过Loader接口将VRML造型文件导入到Java3D场景图中,借助Java语言的事件处理模型,并结合Java3D中的Interpolator内插器对象和Alpha对象,实现交互式添加、拆卸、移动和旋转等装配过程。最后以电机中的转子装配为例,给出了一个基于VRML-Java3D的交互式装配可视化环境。     

面向网络化制造的异地制造场所建模研究

针对面向网络化制造核心技术的远程制造资源的建模和仿真,本文探讨了网络化制造系统的结构,提出了两层的网络化制造资源信息模型,着重分析了任务驱动的网络化制造模式下分布式制造场所和设备的远程建模、仿真和组建方法,采用B/S结构来实现远程制造资源的VRML建模及EAI控制,建立了相应的资源模型。     

异构CAD平台网络零件库系统的研究与实现

为满足不同CAD用户间三维零件资源共享和重用的需求,围绕多CAD平台和网络化,建立了异构CAD平台网络零件库系统体系结构,提出了零件通用三维浏览模型、零件调用与参数化驱动和零件库建库工具的实现方法和过程.并综合应用CAD软件的二次开发接口、AJAX异步通信、Web3D等先进技术,在.NET框架下开发出了针对机电典型行业中标准化、系列化零件三维图形的网络零件库系统,能实现零件三维模型在线浏览和参数化驱动,并能实现对网络零件库数据的有效管理与扩充.     

基于Java3D的机械臂三维虚拟场景创建及运动学仿真

针对常规方法所构建的机械臂运动仿真可视化虚拟环境并非基于网络特性的问题,研究并采用了Java3D与VRML相结合的方法。通过Loader接口导入VRML造型文件并将其添加到Java3D场景图中进行装配,借助Java语言强大的事件处理模型,结合Java3D中的Interpolator内插器对象和Alpha对象,实现了简单的人机交互操作。最后以实验室的某型号四自由度机械臂为例,成功实现了一个基于Java3D的交互式可视化机械臂运动仿真虚拟环境创建,并采用标准的D-H参数法进行了机械臂正、逆运动学分析与仿真。研究结果表明,该基于Java3D开发的机械臂三维运动仿真系统,不仅效果逼真,而且适于网络的传输,实现了既定的效果;该研究工作在机械臂仿真中具有较大的应用价值。     

基于Delphi和VRML的虚拟装配平台的实现

针对目前 CAD软件只生成静态三维装配体 VRML 文件的问题 ,分析了交互式虚拟装配 VRML 文件的事件流程和虚拟产品的顺序装配的机理 ,提取其中可赋值变量 ,利用可视化编程语言 Delphi开发一个实现复杂虚拟装配的平台 ,完成静态 V RML文件到动态交互式虚拟装配文件的自动转换     

A solution to integrate computer-aided design (CAD) and virtual reality (VR) databases in design and manufacturing processes

The use of virtual reality (VR) techniques in industry is subject to very high expectations, as VR has emerged as a popular technology for computer-human interfaces in order to master the shortcomings of CAD systems. 3D CAD models provide a natural way of sharing design information among participants in the production process. VRML is a tool specifically designed for creating 3D virtual worlds on the Web, where these synthetic worlds can give us the ability to visualise objects and navigate the virtual world. This paper describes a system for VRML model visualisation that enables changes in the configuration file, which is written in XML, and that automatically reviews the model including the functional behaviour. From the evaluated VRML model, the connection to a PDM system is provided with a list of elements and their material properties.     

Conceptual design system in a Web-based virtual interactive environment for product development

In this research, a Web-based conceptual design prototype system applied with open-source software (e.g., Java, PHP, etc.) is presented. Aside from the online conceptual design kernel interpreter module, it consists of four parts; a module to extract 3D component hierarchical configurations; a module to plan and view the assembly paths for 3D components; a module to set up the motion paths of components; and, finally, a module to handle the viewing direction of any component or assembly to show the 2D projected drawings in real time. In the first online module, it combines the chosen primitive features with Boolean operators. This module is programmed with the Java 3D module in order to build the CAD components on the platform of interactive design. Then, it infers the 3D configuration by analyzing the 3D modeling history. The configuration is described by a parent–child hierarchical relationship and the relative positions between two features. The positioning information is computed with respect to the VRML specification. The operation and control of the VRML objects is by the behavior modules of a Java applet, which plans the exploded/unexploded paths of the 3-D parts assembly and is specified interactively on the different components. Meanwhile, assigning the viewing direction to show the dynamic assembling process and generating projected drawings is automatically carried out by following the viewpoint assigned by the user. Finally, the system creates the motion file, in VRML format, for the assembly paths and behavioral simulation. This research offers a new virtual environment for collaborating design issues and discussion.     

挤出机动态交互仿真平台的研究与实现

挤出机是一种用于挤出XPS保温板成型的塑料机械,应用前景十分广阔。但因设备的高度复杂性,技术人员很难掌握其结构和工作原理。文中基于虚拟现实技术,应用VRML、3ds Max和Cult3D等开发了挤出机动态交互的虚拟现实平台。该平台可以使用户交互操作虚拟对象,快速熟悉设备性能,具有较高的应用价值。     

基于网络的虚拟数控车削系统研究

文章提出了基于网络、模块化、分布式结构的虚拟车削加工平台.运用虚拟现实建模语言(VRML)和Java语言建立了一个基于网络的虚拟数控车削系统,并描述了其系统体系结构框架和主要功能的实现.使用者可以很容易地在本地网络或异地网络建立其加工环境和系统参数,通过InternetExplorer(IE)浏览器界面进行对虚拟数控车床操作访问,并可以通过网络资源来评价和优化加工工艺.     

<Emphasis Type="Bold">A Web-Based Product Modelling Tool – A Preliminary Development</Emphasis>

This paper presents the preliminary development of a Web-based Product Modelling Tool (WPMT) aimed at enabling collaborative design through the Internet using JAVA 3D with dispersed team members. It is motivated by the emerging need of distant collaborative design required among R&D centres and manufacturers of global-based enterprises, simply to shorten product cycle time and, hence, to enhance their world-wide competitiveness. In this paper, current web 3D technologies are discussed first, then the general architecture of the underlying WPMT is introduced. The proposed WPMT is developed to allow designers/users to create, view, and manipulate product models through the World Wide Web. The main architecture of the proposed WPMT uses a Java servlet embedded in an HTML web page, which can be viewed and edited by authorised users with a Java/Java 3D enabled browser through the Internet. The developed WPMT is to be run on a Java Virtual Machine (JVM), so it is independent of the operation system and computer platform. Since the WPMT is a web-based modelling tool, some handy built-in primary features such as block, wedge, rim, hole, pocket, etc. are included for users to develop their product models. The users can also create their own features as so-called user-defined features. In addition, viewing operations such as rotation, zooming, panning, orthographic projections and so on, are also made available for comprehensiveness in the integrated web-based solid modelling tool. Finally, the proposed WPMT is experimentally implemented.     

基于Web的快速模具远程制造服务系统

数字化和网络化已成为当前制造业最为显著的生产特征。为了改变快速模具的传统制造模式为基于Internet的异地协同开发制造模式,解决逆向工程(RE)、快速成形(RP)、快速模具(RT)设备低利用率与企业得不到快速成形与制造(RP&M)技术服务的矛盾,缩短模具的生产制造周期,迎合新产品快速开发的需求。研究和开发了基于Web的快速模具远程制造服务系统。首先介绍了基于RE/计算机辅助设计(CAD)/RP快速模具开发制造系统的工作流程及其组成;然后阐述了远程制造服务系统的功能设计和关键技术的实现;最后构建了服务系统运行的Web平台。该系统旨在集成已有的RE、CAD、计算机辅助分析(CAE)、RP技术及以此为基础的快速模具制造技术,并以万维网(WWW)为支撑,以RP&M服务中心和各生产力促进中心为服务载体,以为远程用户、服务中心、协同制造企业提供方便快捷的技术信息平台、电子商务平台、制造服务平台为服务宗旨。     

简介虚拟制造中的网络虚拟现实技术

介绍了网络虚拟现实建模语言（VRML），VRML具有动态对象描述和超链接、通用性、扩展性、易实现性等特点。VRML浏览器和生成VRML文件的工具广泛使用于多种平台的计算机，是虚拟制造VM与虚拟设计中的网络虚拟现实技术的基础。     

基于Windows Mobile的机械制图虚拟模型

对基于Windows Mobile平台的机械制图虚拟模型进行了研究,通过分析基于Windows Mobile的虚拟模型开发平台以及Windows Mobile中的3D图形绘制技术,确定了Mesh类的数据需求;研究了VRML标准IndexFaceSet节点的数据结构,获得了VRML文件解析的逻辑关系;设计实现了基于Direct3DMobile的VRML模型3D浏览器,并实现了基于Windows Mobile平台的机械制图虚拟模型系统设计。该系统拓展了虚拟模型库的应用空间,为其他虚拟模型的移动应用提供了基础。     

基于VRML的交互式虚拟装配仿真应用

针对目前CAD软件只生成静态的三维装配体VRML文件的问题,分析了交互式虚拟装配VRML文件的事件流程。虚拟装配中的动态交互性行为使用VRML2.0结合JavaScript进行编程,将机械零部件的动态装配过程以基于VRML的虚拟现实技术来表现出来。     

基于Web的协同CAPP系统开发

阐述了基于Web的协同CAPP系统的开发,提出了相关的应用技术和实现方法,并利用Web技术,将工艺设计知识库,三维（二维）动态工艺文件,协同设计等概念应用于具体企业当中。     

机车电气CAD系统及其关键技术

在 Visual C++6 .0环境下基于 Auto CAD平台 ,利用 Object ARX工具 ,结合 MFC,并采用数据库、ODBC和 Active X等技术 ,研究开发了机车电气 CAD系统 ,包括电气原理图智能工作环境建立 ,元件和导线属性编辑 ,原理图环境与外部数据库连接、查询报表以及电气元件配线图自动生成等功能模块     

Multi-User NC Machining Simulation over the WWW

The realisation of a virtual manufacturing system requires an open network environment to perform 3D graphics simulation or virtual reality information processing among multiple users. This paper introduces a prototype system that employs Java, the virtual reality modelling language (VRML) and the external authoring interface (EAI) to perform NC machining simulation. A client/server paradigm is adopted to construct a multi-user enabled interactive environment. A novel method is presented to update dynamically the geometry of a workpiece being cut in a VRML-based scene. In addition, the prototype system is analysed in terms of functionality and performance.     

An Internet-Based Virtual CNC Milling System

This paper addresses the importance of integrating a virtual Manufacturing (VM) system with the Internet and proposes a web-based, scalable and distributed architecture for developing a platform-independent VM system. A prototype web-based virtual CNC milling system has been developed using Virtual Reality Modelling Language and Java. The user can easily set up machining conditions, operate the virtual milling machine in a web browser, and evaluate and optimise the machining process on the Internet without installing any extra software. The system also provides an open environment, in which user-defined process algorithms can be integrated, evaluated and refined.     

WEB-BASED VIRTUAL CNC MACHINE MODELING AND OPERATION

A CNC simulation system based on internet for operation training of manufacturing facility and manufacturing process simulation is proposed. Firstly, the system framework and a rapid modeling method of CNC machine tool are studied under the virtual environment based on PolyTrans and CAD software. Then, a new method is proposed to enhance and expand the interactive ability of virtual reality modeling language(VRML) by attaining communication among VRML, JavaApplet, JavaScript and Html so as to realize the virtual operation for CNC machine tool. Moreover, the algorithm of material removed simulation based on VRML Z-map is presented. The advantages of this algorithm include less memory requirement and much higher computation. Lastly, the CNC milling machine is taken as an illustrative example for the prototype development in order to validate the feasibility of the proposed approach.