外文翻譯--基于網(wǎng)絡(luò)的虛擬數(shù)控車削系統(tǒng)研究

1、<p>　　畢業(yè)設(shè)計(jì)(論文)外文資料翻譯</p><p>　　系　　部： 機(jī)械工程系 </p><p>　　專 業(yè)： 機(jī)械工程及自動(dòng)化 </p><p>　　姓 名： </p><p&g

2、t;　　學(xué) 號(hào)： </p><p>　　外文出處：Fourth International Conference </p><p>　　on Virtual Reality </p><p>　　

3、附 件： 1.外文資料翻譯譯文；2.外文原文。 </p><p>　　注：請(qǐng)將該封面與附件裝訂成冊(cè)。</p><p>　　附件1：外文資料翻譯譯文</p><p>　　基于網(wǎng)絡(luò)的虛擬數(shù)控車削系統(tǒng)研究</p><p>　　摘要 虛擬加工技術(shù)是虛擬制造（ VM）的系統(tǒng)的一個(gè)關(guān)鍵問題，虛擬加工過程仿真目前是一個(gè)重點(diǎn)研究的領(lǐng)域。本文指出將虛擬

4、制造系統(tǒng)和網(wǎng)絡(luò)結(jié)合的重要性,并且為開發(fā)一個(gè)具有獨(dú)立平臺(tái)的虛擬數(shù)控車削系統(tǒng)提出了一種基于網(wǎng)絡(luò)的，可擴(kuò)展性和分布式體系結(jié)構(gòu)?；诰W(wǎng)絡(luò)的虛擬數(shù)控車削系統(tǒng)已經(jīng)利用虛擬現(xiàn)實(shí)建模語言和Java語言得到了發(fā)展 ，并闡述了系統(tǒng)結(jié)構(gòu)和其主要職能的實(shí)現(xiàn)。用戶可以很容易地設(shè)置加工條件，在網(wǎng)絡(luò)瀏覽器上操作虛擬車削機(jī)器 ,并在互聯(lián)網(wǎng)上評(píng)價(jià)和優(yōu)化加工過程. 關(guān)鍵詞 互聯(lián)網(wǎng) 仿真 虛擬加工 虛擬制造 1 引言

5、 虛擬制造（ VM ）系統(tǒng)是一種理論性的并且以計(jì)算機(jī)為基礎(chǔ)的系統(tǒng)，它用將加工與模型和仿真相結(jié)合來代替現(xiàn)實(shí)加工系統(tǒng)中的實(shí)物和其它操作。實(shí)際虛擬加工系統(tǒng)是具有高度多學(xué)科性質(zhì)。目前的許多研究項(xiàng)目和商業(yè) 的CAD / CAM / CAE系統(tǒng)在其完成時(shí)有很多限制。首先，在虛擬制造系統(tǒng)中許多加工的理論和啟發(fā)必須是整合的和模塊化的。許多虛擬制造系統(tǒng)的設(shè)計(jì)僅僅是針對(duì)具體情況下的特定問題。沒有一個(gè)虛擬制造系統(tǒng)的應(yīng)用程序包含所有的技術(shù),這些技術(shù)是建立一個(gè)加

6、工</p><p>　　一個(gè)完整的虛擬制造系統(tǒng)必須對(duì)實(shí)際中的很多加工方法和原理進(jìn)行模擬，同時(shí)又要對(duì)復(fù)雜的切削加工過程進(jìn)行仿真。其系統(tǒng)體系結(jié)構(gòu)也必須體現(xiàn)組織合理的各模擬仿真功能模塊和良好的對(duì)外信息通訊接口的定義，以促進(jìn)獨(dú)立虛擬機(jī)床加工平臺(tái)應(yīng)用程序協(xié)作開發(fā)和提高系統(tǒng)的兼容性。從這個(gè)意義來講，基于網(wǎng)絡(luò)的虛擬車削加工系統(tǒng)是一個(gè)開放的、模塊化的虛擬制造系統(tǒng)。圖1顯示基于網(wǎng)絡(luò)的虛擬數(shù)控車削加工系統(tǒng)的基本體系結(jié)構(gòu)。</p

7、><p>　　圖1 基于網(wǎng)絡(luò)的虛擬數(shù)控車削加工系統(tǒng)體系結(jié)構(gòu)</p><p>　　2.1 資源支持系統(tǒng)模塊</p><p>　　為了給使用者提供有用信息，一套公用基礎(chǔ)數(shù)據(jù)庫對(duì)于建立完整的虛擬制造系統(tǒng)是不可缺少的，該數(shù)據(jù)庫包括虛擬機(jī)床庫、虛擬刀具庫、虛擬夾具庫、以及材料庫。虛擬機(jī)床庫包括各種類型的機(jī)床幾何特征模型，機(jī)床各部件自由度及其運(yùn)動(dòng)學(xué)規(guī)律。虛擬切削刀具庫包括刀具材料

8、和刀具幾何參數(shù)，如刀具切削刃長(zhǎng)度和直徑等。材料庫包括各種材料物理和機(jī)械性能，如材料強(qiáng)度、剛度等。除此之外，還需要建立一個(gè)專用數(shù)據(jù)庫來保存臨時(shí)的應(yīng)用程序數(shù)據(jù)文件。</p><p>　　2.2 NC控制模塊</p><p>　　該模塊主要作用是翻譯NC程序并將其轉(zhuǎn)化為控制虛擬機(jī)床部件的運(yùn)動(dòng)。它使得操作者操作虛擬機(jī)床就像操作實(shí)際的機(jī)床一樣，同時(shí)也具備一些標(biāo)準(zhǔn)的功能，如點(diǎn)動(dòng)、單段運(yùn)行和手動(dòng)數(shù)據(jù)輸入

9、等。</p><p>　　2.3 仿真環(huán)境模塊</p><p>　　該模塊主要提供給使用者一個(gè)三維交互的應(yīng)用界面來瀏覽和控制虛擬加工過程，同時(shí)也包含一些其他子模塊，如對(duì)工件材料去除過程的實(shí)時(shí)顯示和對(duì)加工參數(shù)評(píng)估。</p><p>　　2.4 用戶控制界面模塊 使用標(biāo)準(zhǔn)的輸入系統(tǒng)，用戶可以構(gòu)建一個(gè)虛擬機(jī)器和工件，其過程包括工件材料的選擇，切削刀具，切削條件，

10、輸入數(shù)控G代碼程序，并用虛擬控制面板控制機(jī)器的運(yùn)動(dòng)。 </p><p>　　2.5 加工參數(shù)仿真模型模塊 這是最復(fù)雜和最關(guān)鍵的模塊。其中包括一些關(guān)鍵的加工參數(shù)，如切削力，切削扭矩，刀具壽命，刀具干涉，和加工過程的經(jīng)濟(jì)性，如單個(gè)成本，這些都必須加以估計(jì)以幫助分析切削過程。3 基于網(wǎng)絡(luò)的虛擬數(shù)控車削系統(tǒng)的功能</p><p>　　支持加工模型建立和在網(wǎng)頁瀏覽器中的三維環(huán)境和互動(dòng)的環(huán)

11、境下模擬整個(gè)加工過程的基于網(wǎng)絡(luò)的具有獨(dú)立平臺(tái)的虛擬數(shù)控車削系統(tǒng)已經(jīng)被開發(fā)了。使用者可以手動(dòng)或自動(dòng)輸入NC程序，并通過虛擬控制面板來操作和控制虛擬機(jī)床，就像操作實(shí)際的機(jī)床一樣。加工過程信息如切削深度、主軸轉(zhuǎn)速、進(jìn)給量、刀具位置和切削時(shí)間都可以動(dòng)態(tài)顯示。虛擬工件材料去除過程進(jìn)行實(shí)時(shí)的連續(xù)的仿真。除此之外，通過開放式界面也可以對(duì)加工過程中出現(xiàn)的干涉現(xiàn)象進(jìn)行檢測(cè)仿真和對(duì)刀具使用壽命進(jìn)行預(yù)測(cè)仿真?；诰W(wǎng)絡(luò)的虛擬數(shù)控切削系統(tǒng)的主要功能總結(jié)如下：&l

12、t;/p><p><b>　　快速建模</b></p><p>　　機(jī)床和刀具可以從公用數(shù)據(jù)庫里根據(jù)需要選擇，工件模型的參數(shù)設(shè)計(jì)可以通過指定的長(zhǎng)、寬、高等參數(shù)來建模，其材料直接從庫里提取。任何移動(dòng)的機(jī)床部件如工作臺(tái)、刀具和工件可以根據(jù)其相對(duì)運(yùn)動(dòng)約束在相對(duì)坐標(biāo)系里建立其幾何模型來保持運(yùn)動(dòng)時(shí)位置關(guān)系。</p><p>　　3.2 高級(jí)圖形渲染易于控制&

13、lt;/p><p>　　該虛擬車削加工系統(tǒng)提供了高級(jí)的圖形顯示引擎和控制功能，替代了昂貴的虛擬現(xiàn)實(shí)設(shè)備。運(yùn)用瀏覽器插件——VRML瀏覽器，客戶可以在三維的虛擬環(huán)境中進(jìn)行操作。3.3 操作</p><p>　　使客戶可以手動(dòng)或自動(dòng)操作虛擬車床。當(dāng)使用手動(dòng)模式時(shí)，使用者可以通過滑動(dòng)虛擬控制面板上的滾動(dòng)條來操縱刀具和工作臺(tái)在 、z方向上的移動(dòng)。在自動(dòng)模式下，將根據(jù)輸入的G代碼程序來控制機(jī)床運(yùn)動(dòng)。操

14、作者可以修改和糾正G代碼并且能立即觀察到其改變后的動(dòng)作結(jié)果。虛擬車削機(jī)床內(nèi)置有一個(gè)G代碼編譯器，且是獨(dú)立的模塊，可以根據(jù)數(shù)控系統(tǒng)的需要來更換。</p><p><b>　　3.4 信息監(jiān)測(cè)</b></p><p>　　在虛擬車削加工過程中，加工條件、過程狀態(tài)、關(guān)鍵加工參數(shù)和結(jié)果包括刀具位置、切削深度、主軸轉(zhuǎn)速、進(jìn)給量、加工時(shí)間、退刀位置等可以自動(dòng)被監(jiān)測(cè)。刀具位置信息動(dòng)

15、態(tài)地顯示在虛擬控制面板的左下角，其他的參數(shù)適時(shí)地顯示在反饋信息在如圖2所示塊內(nèi)：</p><p><b>　　切削環(huán)顯示區(qū)</b></p><p>　　刀具坐標(biāo) 手動(dòng)滾動(dòng)條 G代碼程序輸入?yún)^(qū)</p><p>　　圖2 虛擬車削控制面板的部分內(nèi)容顯示</p><p><b>　　3.5 干

16、涉檢測(cè)</b></p><p>　　該虛擬車削加工系統(tǒng)在加工過程中可以自動(dòng)地檢測(cè)到干涉，并且自動(dòng)停止。在其將要發(fā)生的位置，系統(tǒng)將會(huì)以亮色顯示發(fā)生干涉的程序段。該模塊是個(gè)獨(dú)立的模塊，根據(jù)需要可以用其他更精確的干涉檢驗(yàn)算法來替代</p><p>　　3.6 加工過程特性參數(shù)仿真模型</p><p>　　加工過程特性參數(shù)包括切削力、功率消耗、表面粗糙度、刀具磨

17、損情況和刀具壽命等。然而，許多現(xiàn)有的CAD／CAM／CAE商業(yè)軟件的加工仿真模塊僅僅是針對(duì)實(shí)體圖形幾何仿真，沒有提供對(duì)加工過程特性參數(shù)的仿真。因?yàn)檫@些參數(shù)涉及的因素多而復(fù)雜，只有在特殊情況下的具體問題的特殊用途能被仿真。基于網(wǎng)絡(luò)的虛擬車削加工系統(tǒng)提供了開放的獨(dú)立的系統(tǒng)平臺(tái)，通過它用者可以定義加工過程特性參數(shù)，如對(duì)切削力預(yù)測(cè)和刀具壽命估計(jì)。虛擬加工的模型如圖3所示：</p><p>　　圖3 虛擬切削模型<

18、/p><p>　　4 基于網(wǎng)絡(luò)的虛擬車削系統(tǒng)的功能實(shí)現(xiàn)</p><p><b>　　4.1 干涉檢測(cè)</b></p><p>　　干涉檢測(cè)是虛擬車削仿真系統(tǒng)的一個(gè)關(guān)鍵功能。由于不同的虛擬加工系統(tǒng)對(duì)干涉的定義可能不同，不同的加工命令也應(yīng)對(duì)應(yīng)不同的干涉檢測(cè)模塊。</p><p>　　4.1.1 幾何參數(shù)限制 </p>

19、<p>　　刀具必須在有限X —Z平面的水平方向內(nèi)運(yùn)動(dòng)，也就是X 、Z方向的行程限制。任何試圖使得機(jī)床移動(dòng)部件超越其行程限度的G代碼程序段都將亮顯示出來，并迫使系統(tǒng)停機(jī)，以便給操作者及時(shí)檢查和修改G代碼程序。</p><p>　　4.1.2 速度限制</p><p>　　每個(gè)車削機(jī)床都有固定的加工速度范圍限制，如最大、最小主軸轉(zhuǎn)速，最大進(jìn)給和快速移動(dòng)速度。使用者自己編制G代碼

20、程序必須依據(jù)這些限制，否則將檢測(cè)到干涉現(xiàn)象發(fā)生。</p><p><b>　　附件2：外文原文</b></p><p>　　A study of internet-based virtual NC turning system</p><p>　　ABSTRACT The virtual machining technique is a ke

21、y issue of Virtual Manufacturing (VM) system, and the simulation of virtual machining process is a focus research field at the present time. This paper addresses the importance of integrating a virtual manufacturing syst

22、em with the Internet and proposes a web-based, scalable and distributed architecture for developing a platform-independent virtual NC turning system. A Web-based virtual turning system has been developed using Virtual Re

23、ality Model</p><p>　　Keywords: Internet, Simulation, Virtual machining, Virtual manufacturing</p><p>　　INTRODUCTION</p><p>　　Virtual manufacturing (VM) is a kind of knowledge and co

24、mputer-based system that integrates manufacturing activities with models and simulations instead of objects and other operations in the real manufacturing system. A practical VM system is highly multidisciplinary in natu

25、re. Many of the current research projects and commercial CAD/CAM/CAE systems have restrictions in their completion. Firstly, many machining theories and heuristics must be integrated and modeled in a VM system. Many VM s

26、yste</p><p>　　As the same time, with the rapid development of Internet and related technologies, we can realize remote manufacturing and network manufacturing. Once a VM system is constructed, it can be used

27、 for many purposes: designing a shop-floor layout, estimating control strategies, scheduling, testing control programs, simulating operations in the factory, virtually operating a NC machine at local or on remote, verify

28、ing control commands, avoiding collisions in machining, predicting tool life, training </p><p>　　SYSTEM ARCHiTECTURE OF THE WEB-BASED ViRTUAL NC TURNING SYSTEM</p><p>　　A VM system must simulate

29、 a large number of machining rules and theories, as well as simulate complex machining processes. The system architecture must include well-organized modules for modelling and simulation, and well-defined interfaces to f

30、acilitate group work to produce and reuse compatible and platform-independent applications. From this viewpoint, the system has been selected to construct an open and modularized VM system. The essential modules of the d

31、eveloped web-based virtual NC turni</p><p>　　2.1 Resource support system</p><p>　　In order to provide users with sufficient information for reuse, a set of public databases, including a virtual

32、machine library, a virtual cutting tool library, a virtual fixture library, and a material library, are necessary to serve a complete VM system. The virtual machine library includes various types of machine models with g

33、eometrical features, degrees of freedom, and the physical constraints of the various part movements. The virtual cutting tool library includes cutter materials and geom</p><p>　　NC controller</p><

34、p>　　This plays the great role of interpreting the NC programs and converting them into virtual machine movements. It enables users to control the virtual machine tools in the same way as in reality. Standard functions

35、 such as jog, single block execution, and manual data input are included.</p><p>　　Simulation environment</p><p>　　This provides users with an interface to view and control virtual machining pro

36、cesses in a 3D and interactive mode. It also includes some sub-modules, such as real-time removal of the workpiece and display of estimated machining parameters.</p><p>　　User control interface</p>&l

37、t;p>　　Using the standard input system, users can construct a virtual machine and workpiece, select workpiece materials, cutting tools, cutting conditions, input NC G-code program, and control tool movement with a virt

38、ual control panel.</p><p>　　Machining parameters simulation models</p><p>　　This is the most complex and challenging model. Critical machining characteristics, such as cutting force, torque, too

39、l life, and tool collision, as well as economic process characteristics, such as the cost per part, must be estimated to help in the analysis ofthe cutting processes</p><p>　　FUNCTiONS OF THE WEB-BASED VIRTU

40、AL NC TURNING SYSTEM</p><p>　　The web-based and platform independent virtual NC turning system that has been developed supports the construction of a machine model and the simulation of the entire machining

41、process in a 3D and interactive environment within a web browser. Users can operate the virtual machine manually or automatically with NC programs as in reality. Machining cycle information, such as the depth of cut, axi

42、s speeds, feedrates, positions, and cutting time, are displayed dynamically. The workpiece material rem</p><p>　　3.1 Rapid modeling</p><p>　　Machines and cutters are selected using web-based com

43、ponent libraries. Workpieces can be modelled by specifying the length, width, and height, as well as material type. Any moving parts, such as the worktable, the cutter, and the workpiece are modelled in relative coordina

44、tes to maintain the related positions when moving.</p><p>　　Advanced graphics and easy control</p><p>　　This virtual NC Turning machine provides advanced graphic monitoring and control functions

45、 substituting expensive VR devices. Using VRML Player, which is a plug-in in a web browser, users can move around in the virtual 3D world.</p><p><b>　　Operation</b></p><p>　　Users ca

46、n operate this virtual turning machine in the manual mode or automatic mode. When using the manual mode, the user can control the cutter movement in the X, Zdirections by sliding the scroll bar in the virtual control pan

47、el. In the automatic mode, the virtual turning machine works according to G-code input. The user can correct the G-code program and immediately observe the results of the modified program. The virtual tuming machine has

48、an embedded G-code program interpreter, which is an </p><p>　　information monitoring</p><p>　　In a virtual turning process, machining conditions, process status, critical machining parameters an

49、d results, which include the current position of the cutter, the depth of cut, axis speeds, feedrates, cycle times, distance to go, etc., can be monitored dynamically. The cutter position is dynamically shown at the left

50、-hand lower corner of the control panel. Other parameters are shown from time to time in the feedback information field (Fig. 2).</p><p>　　information display</p><p>　　the cutter's position

51、 scroll-bar G-code input</p><p>　　Collision detection</p><p>　　This virtual NC turning can automatically detect unexpected collisions during a virtual turning process and stop the process

52、automatically. The NC program block where the collision has occurred will be highlighted. This collision detection module is also an independent module that can be substituted when other collision detection algorithms ar

53、e needed</p><p>　　Machining parameters simulation models</p><p>　　Machining parameters include cutting forces, power consumption, surface roughness, tool wear, and tool life. However, many CAD/C

54、AM/CAE applications are only graphical simulations. They do not provide parameter simulations because the modelling of these parameters is too complex and only specific problems in predefined conditions can be modelled f

55、or practical use. This web-based virtual NC turning machine provides an open and platform independent interface through which user-defined process algor</p><p>　　Figure 3. A model of virtual turning</p>

56、;<p>　　FUNCTiONAL iMPLEMENTATiONS OF THE WEB-BASED VIRTUAL NC TURNING</p><p>　　4.1 Collision detection</p><p>　　Collision detection is a key function of the web-based virtual NC turning s

57、ystem. As different machining systems have different definitions of collisions, the collision detection module should be developed separately for different machining demands.</p><p>　　4.1.l Ceometric limits&

58、lt;/p><p>　　The worktable must move horizontally within the specified limits in the X-Z plane. Any G-code program that attempts to make the movable parts of a machine traverse beyond their limits will be highli

59、ghted. This would lead to the pausing ofthe system, giving the user a chance to check and modify the G-code program.</p><p>　　4.1.2 Speed limits</p><p>　　Each turning machine has fixed speed lim