外文翻译--机械装备的发展

机械装备的发展一机械装备的应用近十几年来，随着计算机技术和现代控制理论等相关科技的迅速发展，以数控加工为代表的柔性加工日趋完善，基本上实现了自由曲面形状加工阶段的自动化，但其精加工主要还依靠熟练工人的手工操作。由于手工操作生产效益低下，加工质量不稳定，难以适应自由曲面低成本、短周期、高质量的要求，研究一种高效自动化的研抛设备势在必行，本研究针对自由曲面研抛加工所开发的虚拟轴混联机床就是为了适应这种需求。二状态分析本 所开发的是 联、 联 联 在一 的混联机床。 量 ， 了 种 联机 ， 用 Adams 对 种 联机 行分析， 了3PTT 动 以实现动 动。用 Adams 的机床 联机 ， 行自由研究和动 的 动分析。currency1 表 ， 联机 “ 自由，动 是 动的 动状态。、自由曲面研抛机床的分析fifl机 的 动性，用析 联机 的 ， 联机 的析”形，”所。” 研抛机床 联机 析” 用 的 了自由曲面研抛机床 联机 的 ， 联机 动 为 ，机床的 。 用 表研抛工“的轴势，发现轴势 联机 关，联机 关。、自由曲面研抛机床的动 分析 其currency1机床的动 研究， 机 性 计算、 分析、动 、动、计算机动态currency1等。 是在机 的 行速不 高的 下，动 的 要性就 为 ，由于计算机的不 发展，动 计算、分析、 拟的手段实现了现代化。对机 动 研究的 ， 了机 的 速 一高，对机 的控制为精 的理论基 。、自由曲面研抛机床 的研究机床的研制分为二 分一是 定其机械 机床机设计动 设计行 设计等。二是研制控制 和控制 等。机床应 性 对称性、工作、 向同性的基 上来设计混联机床。自由曲面研抛机床的主、俯视” 3 所。”3 自由曲面研抛机床的主、俯视”六、 论（1） “3 联轴2 联轴”的 坐 联动，用 联机 控制研抛工“的，用 联机 控制研抛工“的势， 效地拓展了研抛加工作业。（2） 了 3PTT 联机 ADAMS 机 ， 行了自由的研究。currency1 表 3PTT 联机 是 动的机 。（3）应用析推导了机床的 联机 的 用 的 了自由曲面研抛机床 联机 的 。 用 表研抛工“的轴势，发现轴势 联机 关， 联机 关。（4）基于影响系数理论 格朗日，推导了 、 联机 动 ， 了 ADAMS 动 currency1 ，currency1 表 机床在 x、y、z 向上的速、加速差异很 。在 z 向需要的速和加速， 滑块均需加同一向的 ，数值相差要足够小，在 x、y 向需要 的速和加速时，在 滑块上 的数值要相差足够 。（5）在自由曲面虚拟轴混联研抛机床的 、 动 动 研究以 前人关于研抛理论的工作基 上，开发了自由曲面虚拟轴混联研抛机床的样机。- 混联研抛机床 动 控制研究1994 年在芝加哥国际机床展览会（IMTS94）上，美国的 Ingersoll 和 Giddings & Lewi公司分 展了名为 Hexapod 和 Variax 的 联机床，引 举世关注。 联机床以 联 为基 ，打破了近 世纪以来单一的以笛卡尔坐 直移为基 的 联机床和 动 原理，被誉为“本世纪机床机 的最 革 创新”、“21 世纪的机床”。其后，意 、日本、俄罗斯、挪威、瑞士、瑞典、丹麦等国的制造商竟相研发 联机床。1997 年底，清华 和天津联合研制了我国第一 联机床 VAMT1Y。传统的 联 机床相比，纯 联 的 联机床在 动性上“ 刚 量比 ， 动 质量小、响应速快，误差累积小， 以很容易地实现 6 轴联动， 动 逆求容易、便于实现实时控制，机床 简单，技术附加值高等优点。但 联机床同时也存在着工作小， 动 的 求困难，控制复杂， 轴存在着 的非性 动耦合， 动 定困难，机床的刚和 动精不高等缺点。为克服 联机床的缺点， - 混联式机床应 生。混联机床几乎继承了 联机床的全优点，同时其工作增 ，动 的求困难 控制复杂均 降低。尽管其刚和动 精仍不 联机床高，但已 强 的生命 。 前，商 化的 联机床已 用。 年的研究发现，研抛 于 性加工，研抛 作用 小， 对机床的刚要求低，同时，研抛机床需要在其行 上 装移- 柔 控制 ，柔 控制 的 装研抛加工对机床 动精的要求被 化。研抛加工所“ 的这 工 性，- 混联机床 短， 以在研抛加工 的应用。基于对 科技发展 点 “精 自动研抛加工 “自由曲面的虚拟轴 用机床”的研究（机床 ” 1），本 就 - 混联研抛机床的 设计、 动 分析、 控制、研抛实等展开研究。对 联 、 联 、混联 机床的 性、 动性、控制性等容 行了分析比，定在 联 3 自由 动 上 联 2 自由的 - 混联形式作为自由曲面研抛机床的 。机床 ” 2。对 3 自由 动 的 形式 行了分析。 坐 ，currency1 其几关系分析 手， 了 联 的“关系，了以克为联fi关fl 下 3 自由 动 的最简单 形式和 工作 机 积比值最 下的 数。基于 联 “关系，了机床的 动 ， 对机床工作的形状、 成 行了 析。本 所 形式的研抛机床“由 段面 成的形工作，工作的上”和下底均为由面 成的复合曲面。 工“性的 引 机床的工作分析， 研抛工“所“ 的，机床工作 分为完全工作、 分工作、小分工作和不工作 。 推理，了机床完全工作的主要影响 是研抛工“ 的 论。机床工作形式 成 ” 3。基于 联 “关系和研抛工“的-态要求，对机床动 逆的 成 求 行了研究。由于研抛态1的存在，工“轴 以形成一以1为的态，机床的 动 逆“ 值、不 定性。为机床的 动 逆合理、一，需加工和 动定 。本 对研抛 研抛态的关系、研抛速 研抛态的关系 行了分析，了足研抛 和研抛速 控制要求的1工 定 ， 基于对加工效、 动等的 ，了定态用 的 动 合 ，了研抛工“态的控制 ，同时了机床 种工作 动 逆的求。态 其 用的”4 和” 5。对 和在 的工 性 行了分析比， 合 前 控制的发展趋势，在的直fi 作为新开发数控系统的 控制式。 合 NURBS 曲面的量定 性，了 NURBS 曲面研抛的 式。对研抛 行 表面 用 高误差、研抛工“ 、曲面曲 的关系（” 6）， 表面加工误差、研抛工“、曲面曲 的关系（” 7）行了为 的分析，了 加工误差的主要影响 ， fl了针对 研 和精 抛 的研抛 行 、 定。坐 虚拟轴研抛机床数控系统的研究一、 我国于 2001 年 式加 WTO 以来，发展迅速。随着 、 天以 一 高新技术产业的发展， 自由曲面的 所 的比 来 ，对自由曲面的加工质量和效要求也 来 高。但是 前对自由曲面的精加工主要还依靠熟练工人的手工操作。由于手工操作生产效益低下，加工质量不稳定，难以适应自由曲面低成本、短周期、高质量的要求，研究一种高效自动化的研抛设备势在必行。本 针对用于自由曲面研抛加工的 JDYP51 坐 虚拟轴研抛机床，研究了一种基于 PMAC 的开 式数控系统。二、虚拟轴机床机 设计的分析本 所研究的是 联、 联 合在一 的混联机床，机床为 3+2 式虚拟轴机床， 3 联轴实现 X、Y、Z 向 3 坐 动， 联机 动动 实现 动，在动 上 装 2 自由 联机 手，联机 下加装主轴装。用机床 行 “自由曲面的研抛加工。机床 ” 1 所，虚拟轴机床的 ” 2 所， 的 联机 由 、动和 导 滑块相 合的机 成 ，用定 ， 一 滑块，一 动 用克fi，滑块由 服机和 杠螺母 驱动，沿导 作上下移动。机床的 联机 fi在动 上，由 动关fl 成，分 绕轴 动来调 研抛工“的。以上所 为 联机 的关系，同时 以用 的 机床 联机 的， 联机 动 为 机床 的关系。、开 式数控系统的硬 设计 实现我们 对 JDYP51 虚拟轴研抛机床的研究，设计用了一种基于PMAC 的开 式数控系统。fifl数控系统所设计的数控装 前已完成，” 4 所，控制装 分由上至下为实时 ，饲服控制 ，控制 ，核心控制 和主轴控制 。制机、PMAC 动控制 、 口 RAM（DPRAM）、 服单元 交流 服机等 成。” 的虚上机和下机的功 块分开，实框以外分为系统的外设备。由框” 以看，PMAC 控制 主机（IPC）的 讯用了 种式。一种是 讯式，一种是用 DPRAM 行数fl 信，主机 PMAC 动控制 主要 ISA 讯，至于控制 和机的状态、所 的、速、跟随误差等数fl则 DPRAM 交信息。”4 JDYP51 NC 装 、开 式数控系统的 研究虚拟轴机床数控系统实现 常工作，需要 分的系统 来行IPC的用户界面应用序IPC PMAC 上下机的 讯序PMAC 对 种输 、输量 行监控的 PLC 序。其 讯序的开发工作量最 、最困难、也最“ 技巧性，Delta Tau 公司 的 Pcomm32 已对 讯序 行了充分的开发，我们 以 Pmac.dll 一用。人机界面应用序用Visual C+6.0 语言 行开发。PLC 序用 Delta Tau 公司 的语言 行设计开发。系统 工作机理” 6 所，、 论本 对 JDYP51 坐 虚拟轴研抛机床的数控系统 行了研究和设计， 了一种基于 PMAC 和 IPC 的 CPU 开 式数控系统，完成了机床的数控装， 数控装对机床 行了初的调试和试 行，实现了基本的 行要求。本论 主要的研究工作 研究成下1对虚拟轴机床机 设计和工作原理 行了分析研究， 分 对机床 联机 、 联机 和主轴研头的析，机床输 输的 逆关系式，为数控系统对机床的 迹 动控制 了基 。2对 编 轴 动控制 (PMAC) 行了 系统的研究，针对本虚拟轴机床设计开发了一种基于 PMAC 和 IPC 的 CPU 开 式数控系统硬 ，fifl硬 设计要求了相应的硬 设施和， 完成了数控系统的控制装。3对 CNC 系统 功 做了 的研究， 了数控系统 框 。fifl数控系统硬 的 设计，了系统 工作机理，同时 了人机控制界面的开发 对系统 设计做了 一的研究。控制界面 实现了分的硬 化，分控制 钮和 灯等硬设施 化为 控制，同时 以fifl需要加 I/O 道，“ 良 的开 性和实时性。4 数控系统的控制装对 JDYP51 坐 虚拟轴研抛机床行了调试， 在调试 完成了数控系统的数设 调 ，初完成了机床的合理 行。 对饲服系统的 PID 调fl 速 馈的分析 ，实现了为理想的 动状态。Polishing Machine DevelopmentYudy and development on hybrid virtual axis machine tool forpolishing free-form surfaces1 IntroductionWith the development of automobile industry,electric industry and some new high-techindustries ,the larger is the proportion of NC machining parts with free-form surface in all, thehigher and higher requirements are made for quality and efficiency of machining on free-formsurfaces. After the roughing method is used, precision machining, such as polishing and polishing,is necessary to obtain required workpiece surfaces. Near for over ten years, With the developmentat a high speed in relevant science and technology, such as the technology of the computer andmodern control theory, etc., flexibility machining become more perfect. The automatic machiningof free-form surfaces come to true basically. However, these subsequent processes of precisionmachining still depend mainly on the handwork of skilled mechanists. Productivity effect ofhandwork is very low and its quality is unstable. As to the machining of free-form surfaces, lowcost and short period and high quality were its main aim. As a result of that, the research of a kindof increasingly automated polishing equipment is imperative. Series-parallel virtual axis machine tools for polishing free-form surfaces meets the requirement .2 Work principle and degree of freedom study on hybrid virtual axis machine tools for polishing The sliding block that was drived by servo electromotor and rolling screw thread-nut move up and down along with rail. The inseries mechanism of the machine tool was linked with move platform. It was made up of two rotation joints. The pose of polishing tools was adjusted around axis. The structure principle of the machine tool is shown as Figure.1.3.Position and pose analysis of series-parallet virtual axis machine tool for polishing free-form surface.Fig2Model of parallel mechanism was established by ADAMS software, It is analyzed out that the parallel mechanism has three DOF and the motion status of move platform is linear motion. it is shown As Fig2Positive position solution of inseries mechanism of machine tools for polishing free-form surfaces was established through homogeneous transformation of the coordinate frames. Inseries and parallel mechanism were regarded moving the platform as the tie, so positive position solution of machine tools was got. Axes position of polishing tools is related to inseries mechanism but not parallel mechanism. It was proved by Euler angles.4 kinetics analysis and simulation of series-parallel virtual axis machine tools for polishing free-form surfacesKinetics analysis of machine tools included inertia force calculate, force analysis, balance of motive force, establishment of kinetics model, dynamic simulation with computer,etc. In the case of increasing velocity of machine tools, the importance of kinetics questions become particularly outstanding. Because of the uninterrupted development of computer, the methods of kinetics calculate and analysis and simulation become modernization. With the deep study of kinetics, the velocity of machine tools was further improved. It offers theory basis for control of the machine tools.The move platform can only realize linear motion in 3D space. There is not rotation kinetic nergy. Then the kinetic energy of move platform is design of machine tools shelfand . 5.Stand on structure of series-parallet virtual axis machine tool for polishing free-form surface.The front view and bottommove platform and end effector,view of the polishing machineetc. Second, there are study andtool for free-form surfaces manufacture of control circuitand so on. There are three perfor-mance indexes :symmetry.worksp-ace.isotropy. On the basisof these, series-parallel machine tools were designed. Overall appearance of machine tools must be aesthetic. There are another requirements with good igidity and stability and enough operation space. Front view and bottom view of machine tools for polishing free-form surfaces are shown as Figure.3.6 conclusion1. Five coordinates axes move together throng three parallel axes and two inseries axes. The position of polishing tools was controlled by parallel mechanism and the pose was controlled by parallel mechanism. Thus, the work space for polishing was increased effectually.2.3PTT parallel mechanism structure model of Adams was established. The problem of degree of freedom was studied. The simulation shows: 3PTT parallel mechanism move linearly.3.Analytics methods were applied to deduct the positive position solution of machine toolsparallel. Positive position solution was obtained by making use of homogeneous transformation of the coordinate frames. Axes pose of polishing tools was expressed by Euler angle. It is shown that the axes pose is related to inseries mechanism,but not parallel mechanism.4.On the basis of influence coefficient theory and Lagrangian equation, it was deducted that the kinetic equation of inseries and parallel mechanism. Kinetic simulation model was established by Adams. The simulation shows: there are much difference of velocity and acceleration in X,Y, Z direction of the machine tool. If it is required that high velocity and acceleration in Z direction, the same direction forces were added to the three siding blocks. The difference of value should be small enough. The difference of force value on the three sliding blocks should be big enough, if requiring high velocity and acceleration in X, Y direction.5.Through studying the structure and kinematics and kinetic of the inseries-parallel virtual axis machine tool for polishing free-form surfaces and on the working foundation of polishing theory of forefathers, it was developed that the sample of inseries-parallel virtual axis machine tool for polishing free-form surfaces.Keywords: parallel mechanism helix theory degree of freedominfluence coefficient free-form surfaces polishingvirtual axis machine toolStudy on the Kinematics and Interpolation Control of the Series-Parallel Hybrid Polishing Machine ToolIn 1994 on the Chicago international exhibition of machine tool (IMTS94), the parallel machine tools of Hexapod and Variax are displayed by the Ingersoll and Giddings & Lewis company of America for the first time, and it is paid close attention by the whole world. Based on the three dimensional parallel mechanism, the parallel machine tool founds a new principle of the construction and the kinematics for the machine tool, and is known as the biggest transformation and innovation of the mechanism for machine tool in this century , the machine tool of the 21 century . In after years, the manufacturers of Italy, Japan, Russia, Norway, Switzerland, Sweden and Danish etc. develop parallel machine tool competitively. In the end of 1997, the first parallel machine tool VAMT1Y of our country was developed by the Tsinghua University and Tianjin University jointly.Compared with the traditional series machine tool, the parallel machine tool has many merits on the aspect of the structure and the kinematics characteristic such as higher proportion of the rigidity and weight, less quality of the moving parts, rapider respond speed, less error accumulation, easier realization for 6 axles uniting to move, easier calculation for inverse kinematics result that is expedient for real time control, simpler structure of machine tool, higher technical additional value and so on. However, the parallel machine tool has also the disadvantages such as smaller work space, more difficult calculation for forward kinematics result, deeper nonlinear coupling among each axis and more complex control for interpolation, more difficult kinematics marking, weakIt is against the shortcomings of the parallel machine tool that the hybrid machine tool with series-parallel conformation has been developed.The series-parallel hybrid machine tool has inherited all advantages of the parallel virtual axis machine tool nearly, and its workspace to be increased, the difficulty to calculate the forward kinematics result and to control the machine tool to be reduced. For these reasons, theer rigidity and movement precision of the machine tool. series-parallel hybrid machine tool has shown powerful vitality though its rigidity and movement precision is still lower than the series machine tool. Observing the conformation of the machine tools to be made recently, mostly of them are series-parallel one.Studying the polishing for many years, the group knows that the polishing machining belongs to flexible machining. In the polishing process, the requirements for the rigidity and the movement precision of the machine tool are both lower because the active force of the polishing process is smaller and the displacement-force obedience controller is installed in the bearing rod of the polishing tool. For these reasons, the series-parallel hybrid machine tool can be used as a better polishing machine tool.Based on the polishing machine tool made by the group, these questions such as the conception design, the kinematics analysis, the interpolation control and the polishing experiment of the series-parallel hybrid polishing machine tool have been discussed deeply in the paper. Fig. 1 is the photo of the machine tool.After analyzing the structure characteristic, the kinematics characteristic and the control characteristic among the series conformation, the parallel conformation and the series-parallel conformation, select the conformation connected 2 series rotation mechanisms on the 3 DOFS translation moving platform as the conformation of the polishing machine tool. Fig. 2 is the mechanisms of the machine tool.The chain structure of 3 DOFS translation platform is analyzed. Through the method ofhomogeneous transformation and the analysis of dimensional geometry connection about the position-posture of the parallel platform, the closed position connection of the parallel platform is given out, and based on it, the conclusion is revealed that the most simple mechanism of the 3 DOFS translation platform is 3 single-link chains mechanism which is symmetrical in space and jointed by Hook joints. The structure parameters are discussed under the condition of the biggest ratio between the workspace and the structure space of the platform.Based on the closed position connection of the parallel platform, the forward kinematics result of the machine tool is given out, and the workspace of the machine tool is discussed in form and shape. The workspace of the series-parallel hybrid virtual axis polishing machine tool is a column space that is made up of 3 circular-arc surfaces, and its top and bottom are both the complex curved surface consists of 4 ball-arc surfaces. The concept of tool flexibility was introduced firstly in the analysis of machine tool workspace, and according to it, the workspace of the machine tool is divided into four kinds of flexible workspace, the full flexible-workspace, the most flexible-workspace, the fraction flexible-workspace and unhandy workspace. The main influence factor on the full flexible-workspace of the machine tool is the bearing rod length of the polishing tool. The workspace of the machine tool is shown as Fig. 3.Based on the closed position connection of the parallel platform and the requirement of position-posture on polishing tool, the inverse kinematics result of the machine tool is analyzed in form and calculating method. Being the polishing posture angle 1, the axes of the polishing tool bearing rod can form a cone with half-angle 1(shown as Fig. 4). That makes the inverse kinematics result of the machine tool have the characteristic of more values and uncertainty. In order to make the inverse kinematics result uniquely, the technical restricting conditions and the motion restricting conditions should be appended. The relations among the active force, the polishing velocity and the polishing posture angle 1 are analyzed, and the technical restricting conditions, the motion restricting conditions are put forward. The method of calculating the polishing posture in four kinds of flexible workspace is introduced. After that, the inverse kinematics result of the machine tool is given out. Fig. 5 is the semi-cone that the axes of the polishing tool bearing rod should be located on.According to the property of the variable definition region of the NURBS curved surface, the polishing path has been planned. For the reason of its excellent property, online direct interpolation control is chosen as the interpolation control method of the new developing system.Based on the analysis about the row space of the polishing trace and its influence factor, the interpolation step size and its influence factor, the methods how to determine the row space of the polishing trace and the interpolation step size are given out. The relation between row space and radius of the curved surface is shown in Fig. 6, and the relation between interpolation step size and radius of the curved surface is shown in Fig. 7.Research on CNC System of five-coordinate Virtual Axis polishing Machine Tool1IntroductionSince our country was affiliated to WTO in due form in 2001, the economic development is speedier. With the development of automobile industry, aeronautics and astronautics industry and some new high-tech industries, the larger is the proportion of NC machining parts with free-form surface in all, the higher and higher requirements are made for quality and efficiency of machining on free-form surfaces. However, these subsequent processes of precision machining still dependmainly on the handwork of skilled mechanists presently. Productivity effect of handwork is very low and its quality is unstable. As to the machining of free-form surfaces, low cost and short period and high quality were its main aim. As a result of that, the research of a kind of increasingly automated polishing equipment is imperative. This paper regards the JDYP51 model five-coordinate virtual axis polishing machine tool for polishing free-form surfaces. We have researched a kind of open architecture CNC system which is based on PMAC.2Mechanism design analysis of virtual axis machine toolThe series-parallel machine tool, which is well arranged by in series and parallel, is researched in this dissertation.It is a “3+2” model virtual axis machine tool .Three parallel axis carry out there movements in Xcoordinates、Ycoordinates and Z coordinates. Parallel mechanism drives move platform to move flatly. In series mechanism which have two degree of freedoms is fixed in move platform. principal axis mechanism is fixed with In series mechanism. The machine tool can be used to polish free-form surfaces of mold. the photo of machine tool is shown as Figure1.The whole structure of virtual axis machine tool is shown as Figure2. The parallel mechanism are composed of still platform, move platform, three poles and a chain that is fix long pole. At one end of every pole, a sliding block is linked. At the other end of it, the move platform is linked by Huke joint. The sliding block that is drived by servo electromotor and rolling screw thread-nut move up and down along with rail. The inseries mechanism of the machine tool is linked with move platform. It is made up of two rotation joints. The pose of polishing tools is adjusted around axis.through geometry relation, three kindsof relation between input and export of move platform are obtained.These are position analysis of parallel mechanism.And Positive position solution of inseries mechanism of machine tools is established through homogeneous transformation of the coordinate frames. Inseries and parallel mechanism are regarded moving the platform as the tie, so the position solution of machine tools can be got.3. Design and realization of open NC system hardware Through research on JDYP51 model five-coordinate virtual axis polishing machine tool, a kind of open NC system is designed on the basis of PMAC.NC equipment has been already manufactured, which is shown as figure 4. The control equipment was divided as: real time show area, servo control area, control circuit area, core control area and main spindle control area.Function module of the machine upside and underside are divided by dashed shown as figure 5.The part outside solid line frame is the exterior system equipments. It is shown as frame diagram that there are two communication mode between PMAC and IPC. One is bus communication mode, the other is DPRAM data communication mode. The communication between IPC and PMAC is realized by ISA bus. The message between controller and the data of position and velocity and following error of electric engineering exchanged.4.Software research on open NC systemThree parts of system software are required to realize the normal work of the NC system of virtual axis polishing machine tool, which are user interface application program of IPC , communication program between IPC and PMAC upside and underside, PLC monitor program for input and output of PMAC. The development of communi