关 键 词：

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 文献 翻译 利用 离线 仿真 结果 模型 变形 实现 实时 遥控 结构 方法

资源描述：

【机械类毕业论文中英文对照文献翻译】利用离线仿真结果和3D模型变形以实现实时遥控结构变形的方法,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,文献,翻译,利用,离线,仿真,结果,模型,变形,实现,实时,遥控,结构,方法

内容简介：

单位代码 02 学号 080105007 分 类 号 TH 密 级 毕业设计文献翻译 院（系）名称工学院机械系 专业名称机械设计制造及其自动化 学生姓名刘文超 指导教师王良文2012 年 3月 20日 黄河科技学院毕业设计(文献翻译) 第 11 页利用离线仿真结果和3D模型变形以实现实时遥控结构变形的方法摘要DTP2，一个为了演示和改进远程操作设备ITER全面的物理测试设备，已经在芬兰建立起来。首个装备有SCEE的RH设备原型CMM已经于2008年10月移交给DTP2。其目的是为了验证CMM/SCEE原型可以被成功的应用于第二个暗盒的RH的运作。在 F4E 授与 DTP2 测试设备运行和升级准备 结束的时候，第二个暗盒的 RH 的运行成功地为F4E代表做了证明。得益于CMM/SCEE机器人的设计，所以当它在3.6米长的控制杆上运载9吨重的第二暗盒时，具有相当大的机械弹性。这也就导致数据不精确，并且用于控制系统的3D模型也不能准确的反映CMM/SCEE机器人的变化状态。 为了提高其精确度，已经发展出了一种在虚拟环境中控制其弹性的方法。加载在CMM/SCEE上载荷的作用大小被测量并且最小化到由控制系统软件执行的载荷补偿模型上。这种优化的方法利用有限元分析，通过3D模型的变形解释了控制系统机器的结果变形。这将促使CMM/SCEE的绝对精度和3D模型的适合性有一个相当大的改进，这对RH应用程序是至关重要的，因为控制装置的视觉信息是受周围环境的限制的。关键词：国际热核实验反应堆 远程控制 偏滤器测试平台2 虚拟工程 弹性变形 虚拟现实1.引言这篇论文展示了系统控制软件执行的负载补偿功能是怎样改进DTP2控制系统的绝对精度和可视化精度的。同时也找到了一种通过3D模型变形来解释DTP2的结构变形的新方法，利用有限元分析来导出变化范围。除此之外，真实的组件变形，2D结构变形会被用于显示每单位结构负荷的运行评估。在第二暗盒安装程序的时候，CMM在电机传动装置的协作下，沿着射线方向行进到维持隧道的顶端。（图1）。在垂直面上的上升和倾斜运动可以用来凭借向上维持隧道来控制暗盒的方位。当热运动到达第二暗盒时，由CRO和HRO回转连接的可以用来改变暗盒的方位。Fig. 1. CMM and SCEE structural representation.2. DTP2的偏差研究目录2.1 CMM/SCEE检验在CMM/SCEE传递到DTP2后，系统综合阶段开始启动，以为实际测试做系统准备。这个测试在工厂启动实施，在RH控制室中结束测试运行。1最初用于暗盒运行的的程序是被用来教学的，这与暗盒有持续性的视觉联系。CMM/SCEE良好的重复精度（3mm）保证了运行程序成功重复。然而，由于CMM/SCEE的完全精度不够准确，导致静态的三维模型不能很好的支持运行。三维模型有时候会出现暗盒与DRM冲突的情况，但实际情况是一切运行良好。很明显，在远程操作之前，系统的绝对精度需要改进。2.2 载荷补偿在运行程序的时候，载荷对CMM-SCEE运动链的影响会被测量。并且知道位于暗盒尖端的定位误差最大接近80mm。这些测量数据被用来生成载荷补偿以改进绝对精度。这种解决方法对于RH维持通道的运行是十分普遍的，但是对于负载补偿模型，确实一个基于CRO莲价值的平台。由于CMM在将来普遍支持其他终端执行器，所以这种方法简单，易用。具体的查表只应用于在特殊的环形SCEE轨道中的操作。补偿功能还可以明显改善设备性能。因此，暗盒尖端的最大误差由80mm下降到了5mm。1载荷补偿的实施价值可以参考图2中的笛卡尔坐标系。根据暗盒是否加载到HRO上，解决的方法也分为两个阶段。“理想设备的笛卡尔参考系”（图2）表达了与轴相连的HRO链的位置坐标。因此，HRO链仅仅被用在改变纵轴周围暗盒的方向，并且，之后CRO链可以应用于y轴参考数据的评估。因此，在热运动时，负载补偿的功能依赖于CRO链。如果在HRO链上没有负载，一个逆运动学解可以直接用于解决联合相应的数值参考。解决方法是使用包括基于签名修正的CMM / SCEE校准的Denavit-Hartenberg参数计算。Fig. 2. Left: load compensation in cartesian space. Right: implementation of load effect to the joint data of the real device.当载荷是连接到HRO关节，在这种情况下，由于笛卡尔参考也会受CMM/SCEE的挠度影响，所以机器人的逆运动学解并不可直接使用。当产生的作用是已知的，正确的评估CRO链的价值可以迭代利用负载补偿或者定义了并列价值与CRO链价值之间的适应性。迭代解和7th多项式都能很好的应用于实践中。CRO价值链被定义后，在x，y，z方向的位置补偿和圆周与径向的定向补偿可以做成笛卡尔参考系。由于CMM/SCEE缺乏在yaw方向上移动的能力，所以无法做运动补偿。Fig. 3. Ansys FEM result (DCM lifted from RH interface).Fig. 4. CATIA FEM result (DCM lifted from RH interface).2.3 改进遥控装置的可视化精度当增加一个链接到CMM/SCEE的三维模型上时，暗盒在yaw方向的倾斜是可视化的。这个链接已经被放置在勾板和暗盒之间。因此，操作者可以看见暗盒倾斜的作用 ，它在垂直方向上最大有效运动距离是10mm。为了增加可视化精度，当暗盒连接DRM通道内部与外部的时候，压力差超过上升油缸提供的载荷，暗盒的重量也转化都勾板或者DRM通道或者其他别的地方。（图2）2.4 偏滤暗盒模型的偏差计算结果在真实的运行环境中，暗盒的三维模型是不能完全反映其模型形状的。当DCM处理终端感应器并停留在环形通道上时，它会倾斜。（图3-5）DCM的形变分别用分析软件和CATIA有限元建模工具来计算。这两种结果会被比较。如果限定条件比较正确、全面，那么两种工具的分析结果是相似的。在下一阶段，有限元分析结果会被分解。然后勾板的水平和垂直偏转会与DTP2实验室中真实的DCM测试结果比较（平台1）。这种测试装置是Sokkia NET05高精度三维调试系统。Fig. 5. Vertical and horizontal deflections in respect to cassette structures.在有限元分析结果和Sokkia NET05测试结果比较后，得出分析结论。2.5 偏滤暗盒的偏差的可视化根据机器的适用性和标准性原则设计了DCM。结果，其压力总是在建筑材料的比例极限之下，并且具有一定的线弹性。初次测是在胡可定律的线弹性假设下进行的。因此，有限元分析结果是可以应用于DCM形变的可视化的。加载装置的形状必然会反映到远程观测系统的数据中。计算变形的远程可视化可以在两种不同的方法下进行。传统的方法是把一个整体分成碎片，并在这些碎片间建立联系4。这种方法需要大量的分析工作。链接的位置和最大链接就是这种分析的结果。基于这种分析结果，它被DCM分为三段链，并用两个回转节链接起来。图6本文提到的方法是运用3D变形3D模型逐渐改变的过程基于有限元分析结果去描述形变。形变，或者是3D变形，是物体从一种形状变为另一种形状的过程2。这种技术可以直接使用有限元分析结果而不用麻烦的求的近似值。另外，这种方法能够运用有限元分析出的每单位范围内的作用结果（图7）。这就提供了一个更高层次的应用能力，以适用于那些接受多个外力影响的复杂系统。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).为了改变模型，我们使用直线切削没变形的三维模型和有限元残缺模型的高点。如果直线切削的精度不足的话，一个更先进的变形算法是应变场插入法。运用达索系统可视化工具5.0来观察变形（图8）。这种虚拟环境是由ITER CATIA与有限元模型连接起来，用于创建变形范围。这种推荐方法的好处有以下几点：运用未加载荷状态和变形状态间的完全弹性变形，来直接使用有限元结果在每单位范围内的最大压力。更容易利用真实系统中离线和在线的变形结果。更加精确的展示复杂系统的各个环节，并且能完全控制连续变形的点，而不粗略的接近。使从复杂系统中分离出单个外力因素引起的变形成为可能。2.6 控制三维模型的变形控制三维模型的变形意味着虚拟环境中的变形必须遵循现实环境中的变形。变形信息可以依据提前测量的运行状态或者运用液压系统的压力来估测外力，因此，运用了现有的传感器信息。考虑到机器人的操作，一个更精确的方法可以通过采用应变规来测量机器人链接的实际变形来达到。在实验室的实验中，应变规将被安装到DCM上。应变规的优势：变形范围方法的互补性，每一个应力都可以通过专用的应变规来单独测量其范围。具有即时测量精确应变的能力，不用依赖于提前测量的静态变形或者不能对每一个应力不能直接使用的液压压力3. 未来工作DTP2的三维虚拟样机组件描述如下。最初，DCM弹性研究集中在解决子系统的弹性问题。然后，研究会包括整个CMM机器结构，并且链接结构接近变形过程。更多复杂的变形途径，如三维领域里的线性插值法将会被使用。这将会联合由真实DCM变形控制的三维样机的弹性变形。我们将进一步分析柔性机器人关节的链接和分离。这将有助于创建更精确的有限元模型。最后，弹性链接的作用和影响会反映到整个系统中。免责声明本文观点不代表欧洲委员会的观点。致谢这项工作是在EURATOM和TEKES的联合契约下，由欧洲委员会支持，在EFDA工作框架下完成的。参考文献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) 269282.3 Han-Bing Yan, Shi-Min Hu, Ralph RMartin, 3D morphing using strain field interpolation, Journal of Computer Science and Technology archive 22 (1) (2007) 147155.4 A.D. Luca, W. Book, Robots with flexible elements, in: Siciliano, Khatib (Eds.), Springer Handbook of Robotics, Springer, 2008, pp. 287319.Fusion Engineering and Design 86 (2011) 19581962Contents lists available at ScienceDirectFusion Engineering and Designjournal homepage: /locate/fusengdesA method for enabling real-time structural deformation in remote handlingcontrol system by utilizing offline simulation results and 3D model morphingSauli Kiviranta, Hannu Saarinen, Harri Mkinen, Boris KrassiVTT Technical Research Centre of Finland, P.O. Box 1300, FI-33101 Tampere, Finlanda r t i c l ei n f oArticle history:Available online 30 December 2010Keywords:ITERRemote handlingDivertor Test Platform 2Virtual engineeringFlexibilityDeformationMorphingVirtual realitya b s t r a c tA full scale physical test facility, DTP2 (Divertor Test Platform 2) has been established in Finland fordemonstrating and refining the Remote Handling (RH) equipment designs for ITER. The first prototypeRH equipment at DTP2 is the Cassette Multifunctional Mover (CMM) equipped with Second Cassette EndEffector (SCEE) delivered to DTP2 in October 2008. The purpose is to prove that CMM/SCEE prototype canbe used successfully for the 2nd cassette RH operations. At the end of F4E grant “DTP2 test facility oper-ation and upgrade preparation”, the RH operations of the 2nd cassette were successfully demonstratedto the representatives of Fusion For Energy (F4E).Due to its design, the CMM/SCEE robot has relatively large mechanical flexibilities when the robotcarries the nine-ton-weighting 2nd Cassette on the 3.6-m long lever. This leads into a poor absoluteaccuracy and into the situation where the 3D model, which is used in the control system, does notreflect the actual deformed state of the CMM/SCEE robot. To improve the accuracy, the new method hasbeen developed in order to handle the flexibilities within the control systems virtual environment. Theeffect 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 structuraldeformations of the robot in the control system through the 3D model morphing by utilizing the finiteelement method (FEM) analysis for morph targets. This resulted in a considerable improvement of theCMM/SCEE absolute accuracy and the adequacy of the 3D model, which is crucially important in the RHapplications, where the visual information of the controlled device in the surrounding environment islimited. 2010 Elsevier B.V. All rights reserved.1. IntroductionThe paper presents how the load compensation functions havebeen implemented in the control system software to improvethe absolute accuracy and visualization accuracy of DTP2 controlsystem. It also proposes a new method for accounting structuraldeformations in DTP2 control system through 3D model morph-ing, utilizing the finite element method (FEM) analysis results formorph targets. In addition to the actual component morphing, the2Dtexturemorphingwillbeutilizedforrepresentingthestructuralload per each component for better operator evaluation.During the 2nd cassette installation process, CMM travels intoradial direction, towards the reactor, on top the maintenance tun-nel rails with the aid of an electric motor drive, Fig. 1. The liftingand tilting motions in the vertical plane are used for controlling theposition and orientation of the cassette according to uphill profileof 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 devotedto change the position and orientation of the cassette during thetoroidal motion towards the place of the 2nd cassette.0920-3796/$ see front matter 2010 Elsevier B.V. All rights reserved.doi:10.1016/j.fusengdes.2010.11.015S. Kiviranta et al. / Fusion Engineering and Design 86 (2011) 1958196219592. Content of DTP2 deflection studies2.1. CMM/SCEE trialsAfter delivery of CMM/SCEE to DTP2, the system integrationphasewasstartedinordertopreparethesystemfortheactualtest-ing. This testing was done in two phases starting from the factoryfloor and ending to the RH operated tests from the control room1.The initial motion programs for the cassette operations weredone by teaching, while having a continuous visual contact withthe cassette. Good repetition accuracy (3mm) of the CMM/SCEEguaranteedsuccessfulrepetitionofthemotionprograms.However,static 3D model could not support operations properly, becauseof poor absolute accuracy of CMM/SCEE. On the grounds of 3Dmodel, it seemed that the cassette was colliding with DivertorRegion Mock-up (DRM) structure although in practice everythingwas fine. It was very clear, that absolute accuracy of the sys-tem should be improved before the remote operations could bestarted.2.2. Load compensationThe 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 ofthe cassette was in the worst case close to 80mm. The measure-ment data was utilized for creating load compensation functions toimprove the absolute accuracy. The solution is general for the RHmaintenance tunnel operations, but for the toroidal operations theload compensation model is a look-up table based on the valuesof the CRO joint. The compensation approach is simple and wellreasoned because of generality for CMM to support future CMMoperations with other end effectors. The specific look-up tablesare used only when operating with SCEE for performing a spe-cific toroidal trajectory in and out. The compensation functionshelpedtoimprovetheperformanceoftheequipmentconsiderably.Thus, the positioning error at the furthest point of the cassette wasreduced from almost 80mm to about 5mm 1.Theimplementationofloadcompensationintothecartesianref-erence values can be seen in Fig. 2. The solution is divided into twophases depending on whether the cassette is loaded to the HRO ornot. Cartesian reference for ideal equipment (Fig. 2) is expressingthe location of a coordinate system (Fig. 1) which coincides withthe axis of the HRO joint. Thereby, HRO joint can be used only forchangingtheorientationofthecassettearoundtheverticalaxisandonly the CRO joint can be used to reach a y-coordinate value of thereference data. For this reason, the load compensation functionsduring the toroidal motions depend on the CRO joint.If there is no load in HRO joint, an inverse kinematics solutioncan be used directly to solve corresponding values for the joint ref-erences. The solution is calculated using the DenavitHartenbergparameters, 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 casethe cartesian reference includes also the components that rep-resent the deflections of CMM/SCEE. When the effect of loadis known, the correct value for CRO joint can be found eitheriteratively utilizing the inverse of the load compensation or bydefining the least-square polynomial fit between the measured y-coordinate values and the corresponding CRO joint values. Bothiterative solution and 7th order polynomial fit are working wellin practice. After the CRO joint value is defined, the positioncompensation in the x-, y- and z-directions and the orientationcompensation in the Roll- (R) and Pitch- (P) directions can bemade with respect to the cartesian reference. The compensationmovement in the Yaw (W) direction cannot be done becauseof lacking the ability to move in the yaw-direction with theCMM/SCEE.Fig. 2. Left: load compensation in cartesian space. Right: implementation of load effect to the joint data of the real device.1960S. Kiviranta et al. / Fusion Engineering and Design 86 (2011) 19581962Fig. 3. Ansys FEM result (DCM lifted from RH interface).Fig. 4. CATIA FEM result (DCM lifted from RH interface).2.3. Improving teleoperator visualization accuracyTilting the cassette in the yaw-direction can be visualized whenan additional joint is added to the 3D model of CMM/SCEE, (Fig. 2).This joint has been placed between the hook plate and cassette.Becauseofthat,theoperatorcanseetheeffectofthecassettetilting,which is 10mm at the end of toroidal movement in the verticaldirection.To increase the visualization accuracy, when the cassette is con-tacting the inner and outer rails of DRM, the pressure differenceover the Lift cylinder provides estimation about the load, as theweight of the cassette is gradually transferred from the hook plateto the DRM rails or the other way around, (Fig. 2).2.4. Calculation of the deflections of the Divertor CassetteMock-upIn the real operation environment, the shape of the DivertorCassette Mock-up (DCM) is never equally represented by the 3D-CAD model. The DCM deflects, when it is handled with the CMMend-effectors and when it rests on the toroidal rails (Figs. 35).The deformations of the DCM were calculated using Ansys soft-ware and CATIA FEM-tools. The results of these two calculationswere compared. In conclusion, both FEM tools provide similarresults if the restraints are specified correctly.In the next phase, the FEM results were divided to components.Then horizontal and vertical deflections of the hook plate handlingand resting on the toroidal rails were compared to measurementsthat had been done for real DCM in the DTP2 laboratory (Table 1).The measurement device is Sokkia NET05 high precision 3D coor-dinate 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 CassetteMock-upDesignoftheDCMhasbeenmadeaccordingtoapplicabledesignrules and standards of the machine design. As a result, the stressesare always below the proportional limit of the construction mate-rial and the behavior of material is linearly elastic. The initial testsin this study were conducted under the Hookes law assumptionfor linear deformations.Hence the results of the FEM analysis can be utilized for thevisualization of the DCM deformations. Problem of loaded deviceshape not being reflected to the teleoperator view makes accuratecontrolofthesystemnearimpossible.Teleoperatorvisualizationbyaccounting deformations can be carried out in two different ways.The traditional method is to divide a body into pieces and to createthelinkmechanismsbetweenthepieces4.Thisapproachrequiresa lot of analysis work. The position of the joints and the maximumjoint values are the result of these analyses. Based on the analyses,it was recommended to divide DCM into three links, which wereconnected with two rotational joints, Fig. 6.Method proposed by this paper is to use the 3D morphing theprocess of gradual transformation between 3D bodies to describethedeformationsofthebodybasedontheFEManalysisresults.Themetamorphosis 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 utilizationof the FEM analysis results directly without laborious link-jointapproximations. In addition, this method enables the use of sep-Table 1FEM results compared to Sokkia measurements.DCM deflectionsCriteriaHorizontalVerticalUnitTotal deformation based on FEMbetween hook plate handling andresting on toroidal rails7.29.2mmSokkia measurements between hookplate handling and resting on thetoroidal rails6.67.3mmS. Kiviranta et al. / Fusion Engineering and Design 86 (2011) 195819621961Fig. 6. The body of the cassette is divided into three rigid links connected with tworotational joints to approximate mechanical flexibilities.Fig. 7. Simplified example of 3 links deformed by 9 individual morph targets(forces).arate deformation results by utilizing FEM results for each morphtarget per force applicable to the component for a given scenario(Fig. 7). This provides a high degree of adaptation capabilities foraccountingalargevarietyofflexibilitiesincomplexsystemswheremultiple sources of forces can affect each part of the system.For morphing the model, we have used the linear interpola-tion between the vertices in the non-deformed 3D model and thedeformed FEM model. A more advanced morphing algorithm is thestrain field interpolation 3 if the accuracy of the linear interpola-tion is not sufficient for the given application.For visualizing the deformations to the teleoperator, DassaultSystems Virtools 5.0 was used (Fig. 8). The virtual environment isbuilt by directly utilizing ITER CATIA models in conjunction withthe 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 agiven maximum force per morph target thus directly utilizingthe FEM results, Fig. 4.Easier reuse of the existing deformation data obtained by theoffline and online analysis of real systems.More accurate representation of each section of the complex sys-tem components and full control over the continuum possibledeformation points, instead of rough estimations gained troughjoint-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 deformationsControlling the 3D model deformations means that the defor-mations in the virtual environment have to follow the actualdeformations. The deformation information can be determinedbased on the previously measured deformations for a givenoperation state or by using the hydraulic system pressuresto estimate the force, hence utilizing existing sensor informa-tion.In the case of robot operations, a more accurate solution can beachieved by employing strain gauges to measure the actual defor-mations of the robot links. In the laboratory tests, the strain gaugeswill be installed to the DCM.The advantage of the strain gauges includes:Complementarity to the morph