【机械类毕业论文中英文对照文献翻译】基于智能代理的分布式数字控制仿真系统
【机械类毕业论文中英文对照文献翻译】基于智能代理的分布式数字控制仿真系统,机械类毕业论文中英文对照文献翻译,机械类,毕业论文,中英文,对照,对比,比照,文献,翻译,基于,智能,代理,分布式,数字控制,仿真,系统
南京理工大学泰州科技学院毕业设计(论文)外文资料翻译系部: 机械工程系 专 业: 机械工程及自动化 姓 名: 徐长庆 学 号: 05010141 (用外文写)外文出处: Proceedings of the Fourth International Conference on Machine Learning and Cybernetics, Guangzhou, 18-21 August 2005 附 件: 1.外文资料翻译译文;2.外文原文。 指导教师评语: 签名: 年 月 日附件1:外文资料翻译译文基于智能代理的分布式数字控制仿真系统摘要 数控仿真是虚拟制造中的一个重要组成部分,可以测试,调试和优化数控程序。然而,基于Web的分布式数控加工系统的发展正面临支持实时网络渲染和远程仿真切削过程智能控制的困难。首先,本文讨论了多代理框架,以EAI为桥梁,采用虚拟现实建模语句来对刀具和工件建模,用Java控制铣削仿真过程。其次,对实现3关键因素的新的编程方法,即时间插值代理, NC代码循环监测代理,动态仿真清除代理,进行了详细的描述。关键词 多代理系统 网络制造 虚拟制造 分布式仿真1 导言虚拟制造系统(VM)是一个以计算机为基础的综合性模式,代表了物理和逻辑架构行为的一个真正的制造系统。在将此应用于生产线上之前进行估算和优化设计,是VM的最主要的的目标。虚拟数控加工是VM的一个重要的组成部分,它可以测试,调试和优化数控程序。数控校验一直是数控加工的一个主要的一部分。传统的数控校验方法是使用真正的廉价材料、真实的机床来进行验证,显然的缺点是花钱,花时间考虑和低效率。网络制造是一个最近几年提出的新概念,它能够集成了内部和外部资源。网络制造的核心是资源共享,这是一个好的办法来降低企业集团的成本。智能仿真技术和网络的迅猛发展使我们能够建立一个基于网络的虚拟数控加工系统。基于web的虚拟数控加工系统可以分布在网络中,使很多用户受益,而无需提高成本的数控验证方法。但是,发展基于网络的虚拟数控加工系统正面临着2个困难。首先是应支持网络实时渲染和远程控制的智能框架。第二个是模拟切割过程,涉及工件动态建模。以铣削仿真作为个案研究,这项研究采用多代理技术实现,通过借助虚拟现实建模语言( VRML的)和JAVE外部创作接口(EAI) 以克服上述困难。2 用于远程仿真的智能代理框架基于网络的三维仿真的智能代理框架是由技术框架和文件框架所组成。分布式数控铣床仿真过程采用基于WEB的3D图形技术。目前典型的支持WEB的3D翻译包只有Java 3D和VRML。3D API是一个作为接口复杂的三维图像和声音渲染系统,它与Java是同一个层次的。Java 3D提供了高层次构建创建和操纵三维几何结构,并建立该几何使用的结构。至于细节渲染,则是自动处理,开发人员利用Java的线程,使用这个Java 3D可以有效地建立精确的虚拟网络。虽然Java 3D是能自动优化改进他们的渲染性能,但是,很难找到一个函数,能够动态对工件进行建模,要求该工件能够进行实时修改。基本的API动态模型的构建应该满足复杂的数据结构和不确定的数据量。和Java 3D相比 ,VRML虚拟现实操作语言,能够通过互联网和超文本链接与万维网来创建网络虚拟世界,是一个更好的办法来创建工件模型以支持远程3D仿真。互动和网络交互可以使用VRML定义,而不必依赖于头盔式设备(HMD)。它的开发VRML的设计者的意图在于使VRML成为交互仿真的万维网的标准语言。易于使用是VRML的优点。 VRML用与用来建立标准的网页的HTML一样的方式来建立三维世界万维网。对于工件建模,关键的优势在于它包含了一些不同的动力学形状节点,来描述一个物体如何呈现,这些将在后面给予描述。上述2个优点决定采取VRML来作为远程三维工件建模的工具。 VRML的一个主要的缺点是,如果只用VRML来建造虚拟场景,它的互动能力较弱。只有导航,移动物体和变化的观点是一致的。动态控制VRML的剖面模型来实现智能仿真很难。EAI是解决困难的一个很好的方法。EAI可以让您控制VRML的浏览器窗口的内容,该窗口嵌入到一个与Java applet同一页的网页。为此,它使用一个浏览器插件接口,该接口允许嵌入到网页的对象可以互相沟通。因此,建立了一个技术框架,该架构由是又基于VRML的刀具和工件模型,基于JAVA的智能铣削过车仿真过程控制和以EAI作为代理的生成者组成。其智能代理框架图如图1所示图1 智能代理框架目前有一些浏览器支持EAI ,如Netscape Communicator的4.04用于Macintosh , Netscape Communicator的4.04为Win32的,还有Netscape Navigator 3.01S适用于IRIX 。有些插件可以用来运行VRML,如用于Macintosh的Cosmo Player 2.1或更高版本。这项研究采用Netscape Communicator的4.04 和 Cosmo Software的Cosmo Player2.1来运行系统。这些文件的框架都如图1 所示。 VRML文件所包含的sta_model.wrl用来建立静态的模型,如刀具模型。dyn_model.wrl用来建立动态模型,如工件的模型。用户通过EAI和导航器和cosmo player的applet来访问和操纵虚拟场景。 VirtualNC.html是虚拟场景和用户之间的接口。3 切削仿真的智能代理为了使数控铣床系统的运行就像是机床工具本身那样,显示出机械运动和材料去除是至关重要的。目前,许多三维建模包是可以达到的,如OpenGL以及的Direct3D软件包 。然而,当使用当前的三维造型包创建的模型沉浸在一个虚拟的环境,其轮廓函数就无法实时修改。这项研究采用了VRML中附有金属光效果的ElevationGrid节点,以实施动态工件大小的变换。xDimension , zDimension ,和高度领域是处理支持节点的VRML ElevationGrid关键领域的动态模型。该xDimension和zDimension领域表明,一些网格高度阵列在X和Z方向上的原理。重复检查是执行实时工件材料去除过程的根本原则。当发现输入NC代码重叠,建立于dyn_model.wrl中动态模型垂直高度上的顶点,以及建立在sta_model.wrl中模型的刀具圆圈内点,将设置与刀具相同的高度。实现铣削仿真包含三个主要代理模块代理,举例如下:(1)时间插补代理DEF TS_XZ TimeSensor cycleInterval 32 loop FALSE ROUTE CLOCK.cycleTime TO SCRIPT.cycleTime ROUTE Trsf_Y.translation_changed TO SCRIPT.Ytranslation ROUTE Trsf_XZ.translation_changedTO SCRIPT.XZtranslation ROUTE SCRIPT.height TO EGRID.set_height(2) NC代码循环监测代理public void ValueChanged extends Applet implements ActionListener, EventOutObserver TheTextField.setText(String.valueOf(TheScrollbar.getValue(); Output.append(Set Scale Value: + x= + ScaleValue0 + y= + ScaleValue1+ z= + ScaleValue2 + n); Output.append(Set Trans Value: + x= + XZTransValue0 + y= + YTransValue1+ z= + XZTransValue2 + n); set_XZtranslation.setValue(XZTransValue); set_Ytranslation.setValue(YTransValue); GcodeInput=new TextArea(init_input, val); add(GcodeInput); (3)动态仿真清除代理set_height_changing( ) if( (var_float+XZPosition0)-(x*Long)*( var_float+XZPosition1)-(x*Long)+(var_float+XZPosition1)-(z*z_Long)*(var_float+XZPosition1)-(z*Long)=(R*R_cut) ) height.setValue( heightFields ); 4 结论一种结合了最新图像技术、智能代理技术、网络技术的分布式智能铣削系统已被成功开发。该系统可以使用户去看、去操作,并且能够在网络上共享一个虚拟数据铣削机床。这个系统检测所有数控程序的错误,可以立即在线纠正。由于这一系统在标准的Windows平台上运行,对用户没有外部的附加要求,因此它很容易使用。致谢本文是湖北省青年精英自然科学基金组织( No.2005ABB023 )所提供 ,武汉市曙光计划( No.20055003059 )附件2:外文原文(复印件)Proceedings of the Fourth International Conference on Machine Learning and Cybernetics, Guangzhou, 18-21 August 2005 INTELLIGENT AGENT-ENABLED DISTRIBUTED NUMERICAL CONTROL SIMULATION SYSTEM YA-BO LUO, DING-FANG CHEN School of Mechanical and Electrical Engineering, Wuhan University of Technology, Wuhan 430070, China E-MAIL: luoyabo1973sohu.com, dfchenpublic.wh.hb.cn Abstract: NC simulation is an important component of virtual manufacturing, which enables testing, debugging and optimizing of NC programs in advance. However, development of web-based distributed NC machining system is facing difficulties of intelligent control supporting real-time rendering over web and the remote simulation of cutting process. First, this paper addresses the multi-agents framework, which employs VRML to model the models of cutter and workpiece, and Java to control the process of milling simulation, taking the EAI as the bridge. Second, the novel programming methodologies for the realization of 3 key majority agents, namely, time the interpolation agent, NC codes flow listener agent, and the dynamical removal simulation agent, are detailed represented. Keywords: Multi-agents system; net manufacturing; virtual manufacturing; distributed simulation 1. Introduction A virtual manufacturing (VM) system is an integrated computer-based model that represents the physical and logical schema and the behavior of a real manufacturing system 1. Pre-estimating and optimizing the design before it is putted on the product line is the main objective of VM. Virtual NC machining is an important component of VM, which enable testing, debugging and optimizing of NC programs. NC verification has always been the majority part of NC machining 2. Traditional method for NC verification is to test the programming using real machine tools with cheap material, obviously which disadvantage is expensive, time taking and low efficient. Net manufacturing is a fresh concept proposed in recently years, which integrates the internal and external resources of enterprises group. The core of net manufacturing is resource sharing, which is a good approach to lower the cost of enterprises group. The rapid development of intelligent simulation and net technologies makes it possible to develop a web-based virtual NC machining system. A web-based virtual NC machining system can be distributed on web to benefit many users without having to improve the cost of NC verification. However, development of web-based virtual NC machining system is facing 2 difficulties 3. The first is the intelligent framework, which should support real-time rendering and remote control over web. The second is the simulation of cutting process involving the workpiece dynamical modeling. Taking milling simulation as case study, this research employs multi-agents technology realized through virtual reality modeling language (VRML) and Jave external authoring interface (EAI) to overcome the above difficulties. 2. Intelligent agents framework for remote simulation The intelligent framework for 3D simulation over web comprises of technologies framework and files framework. The distributed NC milling simulation deals with 3D graphic technology over web. Currently the typical 3D rendering packages on web are Java 3D and VRML. The Java 3D API is a hierarchy of Java classes that serve as the interface to a sophisticated three-dimensional graphics and sound rendering system. Java 3D provides high-level constructs to create and manipulate 3D geometry, and to build the structures used to render that geometry 4. As the details of rendering are handled automatically, developers can efficiently create precise virtual universes on web using this Java 3D package taking advantage of Java threads. Though the Java 3D is capable of automatically optimizing for improved rendering performance, however, it is difficult to find a function to dynamically model the work-piece, which should have capability to be modified in real time. A dynamic model constructed by the elementary API should meet complex data structure and uncertain data amount. Compared to the Java 3D, VRML, which allows to create virtual worlds networked via the Internet and hyperlinked with the World Wide Web, is a better approach to create work-piece model supporting remote 3Dsimulation. Interaction and internetworking can be specified using VRML without being dependent on special gear like head-mounted devices (HMD). It is the intention of its designers to develop VRML as the standard language for interactive simulation within the World Wide Web. Ease to use is an advantage of VRML. VRML is used in the same way to build 3-D worlds on the World Wide Web as HTML is used to build standard Web pages. For work-piece modeling, the crucial advantage is it contains some various dynamical shape nodes comprising of fields to describe how an object is rendered, which will be represented late. The above 2 advantages decide on that it is advisable to take the VRML as the tool for remote 3D work-piece modeling. A main disadvantage of VRML is that a virtual scene constructed with only VRML has poor interaction capability. Only navigation, moving object and viewpoint changing are agreed. Dynamic controlling the profiles of VRML models to realize intelligent simulation is difficult. The EAI is a good solution to the difficulty. EAI allows you to control the contents of a VRML browser window embedded in a web page from a Java applet on the same page. It does this with a browser plug-in interface that allows embedded objects on web page to communicate with each other. Consequently, the technologies framework is built by employing VRML to model the models of cutter and work-piece, and Java to control the process of intelligent milling simulation, taking the EAI as the agent maker. Current there are some browser agree EAI, such as the Netscape Communicator 4.04 for Macintosh, Netscape Communicator 4.04 for Win32, and the Netscape Navigator 3.01S for IRIX. Some plug-ins can be employed to run VRML files, such as Cosmo Player 2.1 or later for Macintosh. This research employs Netscape Communicator 4.04 + Cosmo Software Cosmo Player 2.1 to run the system. The files framework is showed as in Figure 1. VRML files comprise of sta_model.wrl used to build static models such as the cutter model and dyn_model.wrl used to build dynamic models such as the workpiece model. Users visit and manipulate the virtual scene by EAI and applet through the navigator and cosmo player. VirtualNC.html is the interface between virtual scene and users. 3. Intelligent agents for cutting simulation To make a NC milling system to run as if they were on the machine tool itself, showing machine motion and material removal is crucial. Currently, many 3D modeling packages are available such as the OpenGL, and the Direct3D soft packages. However, when a model constructed with a current 3D modeling package is immersed in a virtual environment, its profile function cannot be modified in real time. This research employs the VRML ElevationGrid node attached with the metal light effect to implement a dynamical work-piece with variable sizes. The xDimension, zDimension, and the height fields address the key fields of VRML ElevationGrid node in favor of dynamical modeling. The xDimension and zDimension fields indicate the number of elements of the grid height array in the X and Z directions. Overlap checks is fundamental for implementing the real-time workpiece material removal process. When an overlap is detected along with the inputted NC codes, the heights of these vertices of dynamical model, which is built in the dyn_model.wrl, inside the circle of the cutter, which is modeled in the sta_model.wrl, will be set equal to the height of the cutter. The realization of milling simulation contains 3 key majority agents modules demonstrated as followings. (1) Time interpolation agent DEF TS_XZ TimeSensor cycleInterval 32 loop FALSE ROUTE CLOCK.cycleTime TO SCRIPT.cycleTime ROUTE Trsf_Y.translation_changed TO SCRIPT.Ytranslation ROUTE Trsf_XZ.translation_changedTO SCRIPT.XZtranslation ROUTE SCRIPT.height TO EGRID.set_height (2) NC codes flow listener agent public void ValueChanged extends Applet implements ActionListener, EventOutObserver TheTextField.setText(String.valueOf(TheScrollbar.getValue(); Output.append(Set Scale Value: + x= + ScaleValue0 + y= + ScaleValue1+ z= + ScaleValue2 + n); Output.append(Set Trans Value: + x= + XZTransValue0 + y= + YTransValue1+ z= + XZTransValue2 + n); set_XZtranslation.setValue(XZTransValue); set_Ytranslation.setValue(YTransValue); GcodeInput=new TextArea(init_input, val); add(GcodeInput); (3) Dynamical removal simulation agent set_height_changing() if( (var_float+XZPosition0)-(x*Long)*( var_float+XZPosition1)-(x*Long)+(var_float+XZPosition1)-(z*z_Long)*( var_float+XZPosition1)-(z*Long)=(R*R_cut) ) height.setValue( heightFields ); 4. conclusions A distributed intelligent milling system has been developed by the above key technologies combining the latest graphics, net with intelligent agent technologies. It enables users to see, manipulate, and share a virtual NC milling machine on Internet. This system detects all NC program errors, which can be immediately corrected online. Since this system runs on standard Windows platforms, and no exterior attachment is required to users, thus it is ease to use. Acknowledgements This paper is supported by the Hubei province Natural Science Fund for young elitist (No.2005ABB023), Wuhan city dawn plan (No.20055003059). References 1 K. L. Lee, and S. D. Noh, “Virtual manufacturing system-a test bed of engineering activities”, Annuals of the CIRP, Vol 46, No.1, pp.347-350, 2002. 2 H. Narita, K. Shirase, H. Wakamatsu, A. Tsumaya and E. Arai, “Real-time cutting simulation system of a milling operation for autonomous and intelligent machine tools”, International Journal of Production Research, Vol 40, No.15, pp.3791-3806, 2002. 3 Y. B. Luo, S. K. Ong, D. F. Chen, A. Y. C. Nee, “An Internet-enabled image- and model-based virtual machining system”, International Journal of Production Research, Vol 40, No.10, pp.2269-2289, 2002. 4 L. H. Wang, R. Sams, M. Verner and F. F. Xi, “Integrating Java 3D model and sensor data for remote monitoring and control”, Robotics & Computer-Integrated Manufacting, Vol 19, No.1/2, pp.13-20, 2002.
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