GQ50型鋼筋切斷機(jī)的結(jié)構(gòu)設(shè)計(jì)與運(yùn)動(dòng)仿真【說明書+CAD+仿真】

GQ50型鋼筋切斷機(jī)的結(jié)構(gòu)設(shè)計(jì)與運(yùn)動(dòng)仿真【說明書+CAD+仿真】,說明書+CAD+仿真,GQ50型鋼筋切斷機(jī)的結(jié)構(gòu)設(shè)計(jì)與運(yùn)動(dòng)仿真【說明書+CAD+仿真】,gq50,型鋼,切斷,割斷,結(jié)構(gòu)設(shè)計(jì),運(yùn)動(dòng),仿真,說明書,仿單,cad 單位代碼 02 學(xué)　　號(hào) 080105007 分 類 號(hào) TH 密 級(jí) 畢業(yè)設(shè)計(jì) 文獻(xiàn)翻譯 院（系）名稱 工學(xué)院機(jī)械系 專業(yè)名稱 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 學(xué)生姓名 劉文超 指導(dǎo)教師 王良文 2012 年 3月 20日 黃河科技學(xué)院畢業(yè)設(shè)計(jì)(文獻(xiàn)翻譯) 第 11 頁 利用離線仿真結(jié)果和3D模型變形以實(shí)現(xiàn)實(shí)時(shí)遙控結(jié)構(gòu)變形的方法 摘要 DTP2，一個(gè)為了演示和改進(jìn)遠(yuǎn)程操作設(shè)備ITER全面的物理測(cè)試設(shè)備，已經(jīng)在芬蘭建立起來。首個(gè)裝備有SCEE的RH設(shè)備原型CMM已經(jīng)于2008年10月移交給DTP2。其目的是為了驗(yàn)證CMM/SCEE原型可以被成功的應(yīng)用于第二個(gè)暗盒的RH的運(yùn)作。在 F4E 授與 " DTP2 測(cè)試設(shè)備運(yùn)行和升級(jí)準(zhǔn)備 " 結(jié)束的時(shí)候，第二個(gè)暗盒的 RH 的運(yùn)行成功地為F4E代表做了證明。 得益于CMM/SCEE機(jī)器人的設(shè)計(jì)，所以當(dāng)它在3.6米長(zhǎng)的控制桿上運(yùn)載9噸重的第二暗盒時(shí)，具有相當(dāng)大的機(jī)械彈性。這也就導(dǎo)致數(shù)據(jù)不精確，并且用于控制系統(tǒng)的3D模型也不能準(zhǔn)確的反映CMM/SCEE機(jī)器人的變化狀態(tài)。 為了提高其精確度，已經(jīng)發(fā)展出了一種在虛擬環(huán)境中控制其彈性的方法。加載在CMM/SCEE上載荷的作用大小被測(cè)量并且最小化到由控制系統(tǒng)軟件執(zhí)行的載荷補(bǔ)償模型上。這種優(yōu)化的方法利用有限元分析，通過3D模型的變形解釋了控制系統(tǒng)機(jī)器的結(jié)果變形。 這將促使CMM/SCEE的絕對(duì)精度和3D模型的適合性有一個(gè)相當(dāng)大的改進(jìn)，這對(duì)RH應(yīng)用程序是至關(guān)重要的，因?yàn)榭刂蒲b置的視覺信息是受周圍環(huán)境的限制的。 關(guān)鍵詞：國際熱核實(shí)驗(yàn)反應(yīng)堆 遠(yuǎn)程控制 偏濾器測(cè)試平臺(tái)2 虛擬工程 彈性變形 虛擬現(xiàn)實(shí)  1.引言 這篇論文展示了系統(tǒng)控制軟件執(zhí)行的負(fù)載補(bǔ)償功能是怎樣改進(jìn)DTP2控制系統(tǒng)的絕對(duì)精度和可視化精度的。同時(shí)也找到了一種通過3D模型變形來解釋DTP2的結(jié)構(gòu)變形的新方法，利用有限元分析來導(dǎo)出變化范圍。除此之外，真實(shí)的組件變形，2D結(jié)構(gòu)變形會(huì)被用于顯示每單位結(jié)構(gòu)負(fù)荷的運(yùn)行評(píng)估。 在第二暗盒安裝程序的時(shí)候，CMM在電機(jī)傳動(dòng)裝置的協(xié)作下，沿著射線方向行進(jìn)到維持隧道的頂端。（圖1）。在垂直面上的上升和傾斜運(yùn)動(dòng)可以用來憑借向上維持隧道來控制暗盒的方位。當(dāng)熱運(yùn)動(dòng)到達(dá)第二暗盒時(shí)，由CRO和HRO回轉(zhuǎn)連接的可以用來改變暗盒的方位。 Fig. 1. CMM and SCEE structural representation. 2. DTP2的偏差研究目錄 2.1 CMM/SCEE檢驗(yàn) 在CMM/SCEE傳遞到DTP2后，系統(tǒng)綜合階段開始啟動(dòng)，以為實(shí)際測(cè)試做系統(tǒng)準(zhǔn)備。這個(gè)測(cè)試在工廠啟動(dòng)實(shí)施，在RH控制室中結(jié)束測(cè)試運(yùn)行。[1] 最初用于暗盒運(yùn)行的的程序是被用來教學(xué)的，這與暗盒有持續(xù)性的視覺聯(lián)系。CMM/SCEE良好的重復(fù)精度（3mm）保證了運(yùn)行程序成功重復(fù)。然而，由于CMM/SCEE的完全精度不夠準(zhǔn)確，導(dǎo)致靜態(tài)的三維模型不能很好的支持運(yùn)行。三維模型有時(shí)候會(huì)出現(xiàn)暗盒與DRM沖突的情況，但實(shí)際情況是一切運(yùn)行良好。很明顯，在遠(yuǎn)程操作之前，系統(tǒng)的絕對(duì)精度需要改進(jìn)。 2.2 載荷補(bǔ)償 在運(yùn)行程序的時(shí)候，載荷對(duì)CMM-SCEE運(yùn)動(dòng)鏈的影響會(huì)被測(cè)量。并且知道位于暗盒尖端的定位誤差最大接近80mm。這些測(cè)量數(shù)據(jù)被用來生成載荷補(bǔ)償以改進(jìn)絕對(duì)精度。這種解決方法對(duì)于RH維持通道的運(yùn)行是十分普遍的，但是對(duì)于負(fù)載補(bǔ)償模型，確實(shí)一個(gè)基于CRO蓮價(jià)值的平臺(tái)。由于CMM在將來普遍支持其他終端執(zhí)行器，所以這種方法簡(jiǎn)單，易用。具體的查表只應(yīng)用于在特殊的環(huán)形SCEE軌道中的操作。補(bǔ)償功能還可以明顯改善設(shè)備性能。因此，暗盒尖端的最大誤差由80mm下降到了5mm。[1] 載荷補(bǔ)償?shù)膶?shí)施價(jià)值可以參考圖2中的笛卡爾坐標(biāo)系。根據(jù)暗盒是否加載到HRO上，解決的方法也分為兩個(gè)階段。“理想設(shè)備的笛卡爾參考系”（圖2）表達(dá)了與軸相連的HRO鏈的位置坐標(biāo)。因此，HRO鏈僅僅被用在改變縱軸周圍暗盒的方向，并且，之后CRO鏈可以應(yīng)用于y軸參考數(shù)據(jù)的評(píng)估。因此，在熱運(yùn)動(dòng)時(shí)，負(fù)載補(bǔ)償?shù)墓δ芤蕾囉贑RO鏈。 如果在HRO鏈上沒有負(fù)載，一個(gè)逆運(yùn)動(dòng)學(xué)解可以直接用于解決聯(lián)合相應(yīng)的數(shù)值參考。解決方法是使用包括基于簽名修正的CMM / SCEE校準(zhǔn)的Denavit-Hartenberg參數(shù)計(jì)算。 Fig. 2. Left: load compensation in cartesian space. Right: implementation of load effect to the joint data of the real device. 當(dāng)載荷是連接到HRO關(guān)節(jié)，在這種情況下，由于笛卡爾參考也會(huì)受CMM/SCEE的撓度影響，所以機(jī)器人的逆運(yùn)動(dòng)學(xué)解并不可直接使用。當(dāng)產(chǎn)生的作用是已知的，正確的評(píng)估CRO鏈的價(jià)值可以迭代利用負(fù)載補(bǔ)償或者定義了并列價(jià)值與CRO鏈價(jià)值之間的適應(yīng)性。迭代解和7th多項(xiàng)式都能很好的應(yīng)用于實(shí)踐中。CRO價(jià)值鏈被定義后，在x，y，z方向的位置補(bǔ)償和圓周與徑向的定向補(bǔ)償可以做成笛卡爾參考系。由于CMM/SCEE缺乏在yaw方向上移動(dòng)的能力，所以無法做運(yùn)動(dòng)補(bǔ)償。 Fig. 3. Ansys FEM result (DCM lifted from RH interface). Fig. 4. CATIA FEM result (DCM lifted from RH interface). 2.3 改進(jìn)遙控裝置的可視化精度 當(dāng)增加一個(gè)鏈接到CMM/SCEE的三維模型上時(shí)，暗盒在yaw方向的傾斜是可視化的。這個(gè)鏈接已經(jīng)被放置在勾板和暗盒之間。因此，操作者可以看見暗盒傾斜的作用 ，它在垂直方向上最大有效運(yùn)動(dòng)距離是10mm。 為了增加可視化精度，當(dāng)暗盒連接DRM通道內(nèi)部與外部的時(shí)候，壓力差超過上升油缸提供的載荷，暗盒的重量也轉(zhuǎn)化都勾板或者DRM通道或者其他別的地方。（圖2） 2.4 偏濾暗盒模型的偏差計(jì)算結(jié)果 在真實(shí)的運(yùn)行環(huán)境中，暗盒的三維模型是不能完全反映其模型形狀的。當(dāng)DCM處理終端感應(yīng)器并停留在環(huán)形通道上時(shí)，它會(huì)傾斜。（圖3-5） DCM的形變分別用分析軟件和CATIA有限元建模工具來計(jì)算。這兩種結(jié)果會(huì)被比較。如果限定條件比較正確、全面，那么兩種工具的分析結(jié)果是相似的。 在下一階段，有限元分析結(jié)果會(huì)被分解。然后勾板的水平和垂直偏轉(zhuǎn)會(huì)與DTP2實(shí)驗(yàn)室中真實(shí)的DCM測(cè)試結(jié)果比較（平臺(tái)1）。這種測(cè)試裝置是Sokkia NET05高精度三維調(diào)試系統(tǒng)。 Fig. 5. Vertical and horizontal deflections in respect to cassette structures. 在有限元分析結(jié)果和Sokkia NET05測(cè)試結(jié)果比較后，得出分析結(jié)論。 2.5 偏濾暗盒的偏差的可視化 根據(jù)機(jī)器的適用性和標(biāo)準(zhǔn)性原則設(shè)計(jì)了DCM。結(jié)果，其壓力總是在建筑材料的比例極限之下，并且具有一定的線彈性。初次測(cè)是在胡可定律的線彈性假設(shè)下進(jìn)行的。 因此，有限元分析結(jié)果是可以應(yīng)用于DCM形變的可視化的。加載裝置的形狀必然會(huì)反映到遠(yuǎn)程觀測(cè)系統(tǒng)的數(shù)據(jù)中。計(jì)算變形的遠(yuǎn)程可視化可以在兩種不同的方法下進(jìn)行。傳統(tǒng)的方法是把一個(gè)整體分成碎片，并在這些碎片間建立聯(lián)系[4]。這種方法需要大量的分析工作。鏈接的位置和最大鏈接就是這種分析的結(jié)果?；谶@種分析結(jié)果，它被DCM分為三段鏈，并用兩個(gè)回轉(zhuǎn)節(jié)鏈接起來。圖6 本文提到的方法是運(yùn)用3D變形——3D模型逐漸改變的過程——基于有限元分析結(jié)果去描述形變。形變，或者是3D變形，是物體從一種形狀變?yōu)榱硪环N形狀的過程[2]。這種技術(shù)可以直接使用有限元分析結(jié)果而不用麻煩的求的近似值。另外，這種方法能夠運(yùn)用有限元分析出的每單位范圍內(nèi)的作用結(jié)果（圖7）。這就提供了一個(gè)更高層次的應(yīng)用能力，以適用于那些接受多個(gè)外力影響的復(fù)雜系統(tǒng)。 Fig. 6. The body of the cassette is divided into three rigid links connected with two rotational joints to approximate mechanical flexibilities. Fig. 7. Simplified example of 3 links deformed by 9 individual morph targets (forces). 為了改變模型，我們使用直線切削沒變形的三維模型和有限元?dú)埲蹦Ｐ偷母唿c(diǎn)。如果直線切削的精度不足的話，一個(gè)更先進(jìn)的變形算法是應(yīng)變場(chǎng)插入法。 運(yùn)用達(dá)索系統(tǒng)可視化工具5.0來觀察變形（圖8）。這種虛擬環(huán)境是由ITER CATIA與有限元模型連接起來，用于創(chuàng)建變形范圍。 這種推薦方法的好處有以下幾點(diǎn)： 運(yùn)用未加載荷狀態(tài)和變形狀態(tài)間的完全彈性變形，來直接使用有限元結(jié)果在每單位范圍內(nèi)的最大壓力。 更容易利用真實(shí)系統(tǒng)中離線和在線的變形結(jié)果。 更加精確的展示復(fù)雜系統(tǒng)的各個(gè)環(huán)節(jié)，并且能完全控制連續(xù)變形的點(diǎn)，而不粗略的接近。 使從復(fù)雜系統(tǒng)中分離出單個(gè)外力因素引起的變形成為可能。 2.6 控制三維模型的變形 控制三維模型的變形意味著虛擬環(huán)境中的變形必須遵循現(xiàn)實(shí)環(huán)境中的變形。變形信息可以依據(jù)提前測(cè)量的運(yùn)行狀態(tài)或者運(yùn)用液壓系統(tǒng)的壓力來估測(cè)外力，因此，運(yùn)用了現(xiàn)有的傳感器信息。 考慮到機(jī)器人的操作，一個(gè)更精確的方法可以通過采用應(yīng)變規(guī)來測(cè)量機(jī)器人鏈接的實(shí)際變形來達(dá)到。在實(shí)驗(yàn)室的實(shí)驗(yàn)中，應(yīng)變規(guī)將被安裝到DCM上。 應(yīng)變規(guī)的優(yōu)勢(shì)： 變形范圍方法的互補(bǔ)性，每一個(gè)應(yīng)力都可以通過專用的應(yīng)變規(guī)來單獨(dú)測(cè)量其范圍。 具有即時(shí)測(cè)量精確應(yīng)變的能力，不用依賴于提前測(cè)量的靜態(tài)變形或者不能對(duì)每一個(gè)應(yīng)力不能直接使用的液壓壓力 3. 未來工作 DTP2的三維虛擬樣機(jī)組件描述如下。最初，DCM彈性研究集中在解決子系統(tǒng)的彈性問題。然后，研究會(huì)包括整個(gè)CMM機(jī)器結(jié)構(gòu)，并且鏈接結(jié)構(gòu)接近變形過程。 更多復(fù)雜的變形途徑，如三維領(lǐng)域里的線性插值法將會(huì)被使用。這將會(huì)聯(lián)合由真實(shí)DCM變形控制的三維樣機(jī)的彈性變形。 我們將進(jìn)一步分析柔性機(jī)器人關(guān)節(jié)的鏈接和分離。這將有助于創(chuàng)建更精確的有限元模型。最后，彈性鏈接的作用和影響會(huì)反映到整個(gè)系統(tǒng)中。 免責(zé)聲明 本文觀點(diǎn)不代表歐洲委員會(huì)的觀點(diǎn)。 致謝 這項(xiàng)工作是在EURATOM和TEKES的聯(lián)合契約下，由歐洲委員會(huì)支持，在EFDA工作框架下完成的。 參考文獻(xiàn) [1] Internal Reports of Grant “DTP2 test facility operation and upgrade preparation”, 2010. [2] J. Gomes, B. Costa, L. Darsa, L. Velho, Graphical objects, Visual Computer 12 (1996) 269–282. [3] Han-Bing Yan, Shi-Min Hu, Ralph RMartin, 3D morphing using strain field interpolation, Journal of Computer Science and Technology archive 22 (1) (2007) 147–155. [4] A.D. Luca, W. Book, Robots with flexible elements, in: Siciliano, Khatib (Eds.), Springer Handbook of Robotics, Springer, 2008, pp. 287–319. Fusion Engineering and Design 86 (2011) 19581962 Contents lists available at ScienceDirect Fusion Engineering and Design journal homepage: A method for enabling real-time structural control results and 3D model morphing Sauli Krassi VTT article Article Available Keywords: ITER Remote Divertor Virtual Flexibility Deformation Morphing Virtual reality facility, DTP2 (Divertor Test Platform 2) has been established in Finland for the Remote Handling (RH) equipment designs for ITER. The first prototype the Cassette Multifunctional Mover (CMM) equipped with Second Cassette End to DTP2 in October 2008. The purpose is to prove that CMM/SCEE prototype can 2nd cassette RH operations. At the end of F4E grant “DTP2 test facility oper- the RH operations of the 2nd cassette were successfully demonstrated Fusion For Energy (F4E). CMM/SCEE robot has relatively large mechanical flexibilities when the robot 2nd Cassette on the 3.6-m long lever. This leads into a poor absolute where the 3D model, which is used in the control system, does not reflect the actual deformed state of the CMM/SCEE robot. To improve the accuracy, the new method has been developed in order to handle the flexibilities within the control systems virtual environment. The effect of the load on the CMM/SCEE has been measured and minimized in the load compensation model, which is implemented in the control system software. The proposed method accounts for the structural deformations of the robot in the control system through the 3D model morphing by utilizing the finite 1. been the system. deformations ing, morph 2D load radial nel and position of 0920-3796/$ doi: element method (FEM) analysis for morph targets. This resulted in a considerable improvement of the CMM/SCEE absolute accuracy and the adequacy of the 3D model, which is crucially important in the RH applications, where the visual information of the controlled device in the surrounding environment is limited. 2010 Elsevier B.V. All rights reserved. Introduction The paper presents how the load compensation functions have implemented in the control system software to improve absolute accuracy and visualization accuracy of DTP2 control It also proposes a new method for accounting structural in DTP2 control system through 3D model morph- utilizing the finite element method (FEM) analysis results for targets. In addition to the actual component morphing, the texture morphing will be utilized for representing the structural per each component for better operator evaluation. During the 2nd cassette installation process, CMM travels into direction, towards the reactor, on top the maintenance tun- rails with the aid of an electric motor drive, Fig. 1. The lifting tilting motions in the vertical plane are used for controlling the and orientation of the cassette according to uphill profile the maintenance tunnel. The SCEE, which consists of the can- Corresponding author. Tel.: +358 504118792. E-mail address: sauli.kivirantavtt.fi (S. Kiviranta). Fig. 1. CMM and SCEE structural representation. tilever (CRO) and the hook-plate (HRO) rotational joints, is devoted to change the position and orientation of the cassette during the toroidal motion towards the place of the 2nd cassette. see front matter 2010 Elsevier B.V. All rights reserved. 10.1016/j.fusengdes.2010.11.015 system by utilizing offline simulation Kiviranta , Hannu Saarinen, Harri Mkinen, Boris Technical Research Centre of Finland, P.O. Box 1300, FI-33101 Tampere, Finland info history: online 30 December 2010 handling Test Platform 2 engineering abstract A full scale physical test demonstrating and refining RH equipment at DTP2 is Effector (SCEE) delivered be used successfully for the ation and upgrade preparation”, to the representatives of Due to its design, the carries the nine-ton-weighting accuracy and into the situation deformation in remote handling S. Kiviranta et al. / Fusion Engineering and Design 86 (2011) 19581962 1959 2. Content of DTP2 deflection studies 2.1. CMM/SCEE trials After delivery of CMM/SCEE to DTP2, the system integration phase was started in order to prepare the system for the actual test- ing. This testing was done in two phases starting from the factory floor and ending to the RH operated tests from the control room 1. The initial motion programs for the cassette operations were done by teaching, while having a continuous visual contact with the cassette. Good repetition accuracy (3 mm) of the CMM/SCEE guaranteed successful repetition of the motion programs. However, static 3D model could not support operations properly, because of poor absolute accuracy of CMM/SCEE. On the grounds of 3D model, it seemed that the cassette was colliding with Divertor Region Mock-up (DRM) structure although in practice everything was fine. It was very clear, that absolute accuracy of the sys- tem should be improved before the remote operations could be started. 2.2. Load compensation The effect of load to the CMM-SCEE kinematic chain (body, wheels, links and joints) was measured during the motion pro- grams. And it was realized that the positioning error at the tip of the cassette was in the worst case close to 80 mm. The measure- ment data was utilized for creating load compensation functions to improve the absolute accuracy. The solution is general for the RH maintenance tunnel operations, but for the toroidal operations the load compensation model is a look-up table based on the values of the CRO joint. The compensation approach is simple and well reasoned because of generality for CMM to support future CMM operations with other end effectors. The specific look-up tables are used only when operating with SCEE for performing a spe- cific toroidal trajectory in and out. The compensation functions helped to improve the performance of the equipment considerably. Thus, the positioning error at the furthest point of the cassette was reduced from almost 80 mm to about 5 mm 1. Theimplementationofloadcompensationintothecartesianref- erence values can be seen in Fig. 2. The solution is divided into two phases depending on whether the cassette is loaded to the HRO or not. Cartesian reference for ideal equipment (Fig. 2) is expressing the location of a coordinate system (Fig. 1) which coincides with the axis of the HRO joint. Thereby, HRO joint can be used only for changing the orientation of the cassette around the vertical axis and only the CRO joint can be used to reach a y-coordinate value of the reference data. For this reason, the load compensation functions during the toroidal motions depend on the CRO joint. If there is no load in HRO joint, an inverse kinematics solution can be used directly to solve corresponding values for the joint ref- erences. The solution is calculated using the DenavitHartenberg parameters, which include corrections based on the signature cal- ibration of the CMM/SCEE 1. When the load is attached to the HRO joint, the inverse kine- matics solution cannot be used directly because in this case the cartesian reference includes also the components that rep- resent the deflections of CMM/SCEE. When the effect of load is known, the correct value for CRO joint can be found either iteratively utilizing the inverse of the load compensation or by defining the least-square polynomial fit between the measured y- coordinate values and the corresponding CRO joint values. Both iterative solution and 7th order polynomial fit are working well in practice. After the CRO joint value is defined, the position compensation in the x-, y- and z-directions and the orientation compensation in the Roll- (R) and Pitch- (P) directions can be made with respect to the cartesian reference. The compensation movement in the Yaw (W) direction cannot be done because of lacking the ability to move in the yaw-direction with the CMM/SCEE. Fig. 2. Left: load compensation in cartesian space. Right: implementation of load effect to the joint data of the real device. 1960 S. Kiviranta et al. / Fusion Engineering and Design 86 (2011) 19581962 2.3. an This Because which direction. tacting over weight to 2.4. Mock-up Cassette CAD end-effectors ware were results Then and that The dinate Fig. 3. Ansys FEM result (DCM lifted from RH interface). Fig. 4. CATIA FEM result (DCM lifted from RH interface). Improving teleoperator visualization accuracy Tilting the cassette in the yaw-direction can be visualized when additional joint is added to the 3D model of CMM/SCEE, (Fig. 2). joint has been placed between the hook plate and cassette. of that, the operator can see the effect of the cassette tilting, is 10 mm at the end of toroidal movement in the vertical To increase the visualization accuracy, when the cassette is con- the inner and outer rails of DRM, the pressure difference the Lift cylinder provides estimation about the load, as the of the cassette is gradually transferred from the hook plate the DRM rails or the other way around, (Fig. 2). Calculation of the deflections of the Divertor Cassette In the real operation environment, the shape of the Divertor Mock-up (DCM) is never equally represented by the 3D- model. The DCM deflects, when it is handled with the CMM and when it rests on the toroidal rails (Figs. 35). The deformations of the DCM were calculated using Ansys soft- and CATIA FEM-tools. The results of these two calculations compared. In conclusion, both FEM tools provide similar if the restraints are specified correctly. In the next phase, the FEM results were divided to components. horizontal and vertical deflections of the hook plate handling resting on the toroidal rails were compared to measurements had been done for real DCM in the DTP2 laboratory (Table 1). measurement device is Sokkia NET05 high precision 3D coor- measuring system (theodolite). Fig. 5. Vertical and horizontal deflections in respect to cassette structures. Comparison between the FEM results and the Sokkia measure- ments showed that the real DCM behaves as it was analyzed. 2.5. Visualization of the deflections of the Divertor Cassette Mock-up Design of the DCM has been made according to applicable design rules and standards of the machine design. As a result, the stresses are always below the proportional limit of the construction mate- rial and the behavior of material is linearly elastic. The initial tests in this study were conducted under the Hookes law assumption for linear deformations. Hence the results of the FEM analysis can be utilized for the visualization of the DCM deformations. Problem of loaded device shape not being reflected to the teleoperator view makes accurate controlofthesystemnearimpossible.Teleoperatorvisualizationby accounting deformations can be carried out in two different ways. The traditional method is to divide a body into pieces and to create the link mechanisms between the pieces 4. This approach requires a lot of analysis work. The position of the joints and the maximum joint values are the result of these analyses. Based on the analyses, it was recommended to divide DCM into three links, which were connected with two rotational joints, Fig. 6. Method proposed by this paper is to use the 3D morphing the process of gradual transformation between 3D bodies to describe the deformations of the body based on the FEM analysis results. The metamorphosis or the (3D) morphing of the 3D graphical objects, also known as shape interpolation, is the process of transform- ing one shape into another 2. This technique allows utilization of the FEM analysis results directly without laborious link-joint approximations. In addition, this method enables the use of sep- Table 1 FEM results compared to Sokkia measurements. DCM deflections Criteria Horizontal Vertical Unit Total deformation based on FEM between hook plate handling and resting on toroidal rails 7.2 9.2 mm Sokkia measurements between hook plate handling and resting on the toroidal rails 6.6 7.3 mm S. Kiviranta et al. / Fusion Engineering and Design 86 (2011) 19581962 1961 Fig. rotational Fig. (forces). arate target ( accounting multiple tion deformed strain tion Systems built the 6. The body of the cassette is divided into three rigid links connected with two joints to approximate mechanical flexibilities. 7. Simplified example of 3 links deformed by 9 individual morph targets deformation results by utilizing FEM results for each morph per force applicable to the component for a given scenario Fig. 7). This provides a high degree of adaptation capabilities for a large variety of flexibilities in complex systems where sources of forces can affect each part of the system. For morphing the model, we have used the linear interpola- between the vertices in the non-deformed 3D model and the FEM model. A more advanced morphing algorithm is the field interpolation 3 if the accuracy of the linear interpola- is not sufficient for the given application. For visualizing the deformations to the teleoperator, Dassault Virtools 5.0 was used (Fig. 8). The virtual environment is by directly utilizing ITER CATIA models in conjunction with FEM models that are utilized for creating morph targets. The benefits of the proposed method are the following: Applicationofthefullyflexiblemeshmorphingbetweenthecom- ponents unloaded neutral states and the deformed states for a given maximum force per morph target thus directly utilizing the FEM results, Fig. 4. Easier reuse of the existing deformation data obtained by the offline and online analysis of real systems. More accurate representation of each section of the complex sys- tem components and full control over the continuum possible deformation points, instead of rough estimations gained trough joint-link approximation. Possibility to combine multiple deformations separated by indi- vidual forces in complex system. Fig. 8. Example of DCM morph targets within virtual environment. 2.6. Controlling of the 3D model deformations Controlling the 3D model deformations means that the defor- mations in the virtual environment have to follow the actual deformations. The deformation information can be determined based on the previously measured deformations for a given operation state or by using the hydraulic system pressures to estimate the force, hence utilizing existing sensor informa- tion. In the case of robot operations, a more accurate solution can be achieved by employing strain gauges to measure the actual defor- mations of the robot links. In the laboratory tests, the strain gauges will be installed to the DCM. The advantage of the strain gauges includes: Complementarity to the morph target method, where for each force one can have an individual morph target controlled by a dedicated strain gauge. Ability to measure the exact deformations immediately, not relying on the previously measured static deformation data or hydraulic pressures that may not be available for all force direc- tions. 3. Future work The continuation regarding the fully flexible 3D virtual proto- typing of the DTP2 robot components will be as follows. Initially, the DCM flexibility studies will focus on solving the flexibility prob- lems of subsystems. Later, the studies will cover the whole CMM robot structures and will result in appropriate joint structures of the rigid objects to reflect the deformed states of the preceding objects in the link chain. More sophisticated morphing methods such as the 3D strain fields in replacement of the linear interpolation will be applied. This will be combined with the flexible 3D virtual prototype to be controlled by the strain gauges measurements of the real DCM deformations. We will further analyze the combined and separate effect of the flexibility of the robot links and the joints. This will help to create a more precise FEM models. Finally, the influence of the link flexibilities on the dynamic response of the system will be explored. 1962 S. Kiviranta et al. / Fusion Engineering and Design 86 (2011) 19581962 Disclaimer The views and opinions expressed herein do not necessarily reflect those of the European Commission. Acknowledgements This work is supported by the European Commission under the contract of association between EURATOM/TEKES, was carried out within the frame-work of the European Fusion Development Agreement. References 1 Internal Reports of Grant “DTP2 test facility operation and upgrade preparation”, 2010. 2 J.Gomes,B.Costa,L.Darsa,L.Velho,Graphicalobjects,VisualComputer12(1996) 269282. 3 Han-Bing Yan, Shi-Min Hu, Ralph R Martin, 3D morphing using strain field inter- polation, Journal of Computer Science and Technology archive 22 (1) (2007) 147155. 4 A.D. Luca, W. Book, Robots with flexible elements, in: Siciliano, Khatib (Eds.), Springer Handbook of Robotics, Springer, 2008, pp. 287319.