翻译
Industrial Material Handling and Process Applications of Robots Replacing humans with robots to perform processes has often led to failure. The reason is that the robots are often mechanically capable of the manipulation while being incapable of process planning and control. Thousands of robot installations have failed because replacing the manual method with the automatic method lacked adaptability to process related variation. The human operators had been using their cognitive abilities to do the job. A vast majority of successful robot implementations past and present have a very important common aspect: repeated ex ecution of fix ed programs with little or no on-line modifi cation of path or position.
Process robot planning and programming still usually require the efforts of highly skilled technicians. Often, complex programs cost too much and take too long. Continuously controlling and varying path manipulation parameters for real-time process control is dif ficult. Man y processes are not known well enough to describe their control algorithmically. In a few applications sensors are becoming more common for adapting robot plans to changes in the environment. Setup, seam tracking, positioning, conveyor tracking, and no w automatic programming for painting and fi nishing are becoming practical as sensor costs and computation costs continue to decline.
In this section robotic material handling and process applications are presented from an automation system perspective focusing on the robot’s manipulation functions. Manipulation is considered a man- ufacturing material transformation and a transportation process factor. Programming and control are viewed as the means of integrating robot manipulation as part of the manufacturing process. The reader who is interested in a specific application is encouraged to fi rst review the relevant process technology sections of this book.
Implementation of Manufacturing Process Robots
Manipulation as a Process Requirement
The starting point of automation system design is a thorough understanding of the process to be automated. Implementation of a process robot requires a focus on manipulation as a process factor. The pose and path requirements of the process are independent of the manipulator used.
It is useful to conduct a static spatial analysis of manipulation requirements and then examine the mechanical and dynamic requirements when designing or selecting a process robot manipulator.
A spatial description of the relative positions and orientations of the workpiece and tool during processing provides the basis for describing the required manipulation. Tool poses are graphed in an appropriate reference frame, usually the frame of the workpiece, or in the case of machine loading, the w ork holding fixture may be used. P ath requirements are secondary for these applications. The path taken does not affect the process. For continuous path processes entire paths must be graphed or mapped. If continuous analytical descriptions of the path are not available, a sampling of discrete points along the required path can be used to represent the space occupied by the path. The result in both cases is a Cartesian mapping of spatial requirements of pose and path. A description of the pose and path precision requirements should be included. Ne xt the mechanical and dynamic requirements are defi ned. Payload and force reactions at each position and along the path must be understood. Other important dynamic requirements such as acceleration and po wer should be quantifi ed. The manipulation requirements are the basis for design and selection of both the robot arm and the controller.
Manipulation Capability of Process Robots
The basic mechanical capability of the robot mechanism to perform the manipulation work is determined by its mechanical structure, kinematic confi guration, and drive mechanism. There are several applications including painting, palletizing, spot welding, and arc welding for which specifi c types of robot arm
designs have evolved driven by process needs. Although predisposed by design to perform a particular process, these robots have no innate process capability and are not guaranteed to perform in a specifi c application. Specifi cations of gross robot performance characteristics such as reach, repeatability, accu- racy, and payload are usually readily available from their manufacturers. A well-defined set of process manipulation requirements when compared with published robot specifications usually isolates the fi eld of mechanically qualifi ed candidates. It is more dif ficult to characterize and e valuate a robot’s capability for complex motion. The exact working of the robot’s trajectory generation software is usually not known by end users and can only be evaluated by indirect testing. Acceleration and load capacity are usually specified, and there are some standard methods for specifying path performance, b ut the robot’s dynamic behavior and performance are dif ficult to measure. Specifi c performance testing is usually required to prove manipulability for process robot applications.
Integration of Manipulation Control and Process Control
Achieving manipulator and process control integration depends upon robot programming and external data access. For any given application the required motion execution may be possible, but programming may be too dif ficult to be practical. Establishing that the robot is capable of coordinated motion can be done by revie wing the specifi cations or by conducting motion tests. As an illustration of the importance of programmability consider, for example, a situation in which a complex series of twisted curv es define a robot tool path. If two robots with identical kinematic structure and joint trajectory generation capability differ in their programming in that one is capable of executing paths following user-defined mathematical functions and the other is only capable of ex ecuting paths defi ned by closely spaced taught poses, the difference in programming effort could easily amount to hundreds of hours. For each application encountered the programming methods must be assessed to determine if the required motion is pro- grammable in a practical sense.
Access by process robot programs to external data is becoming more important. Although most process robots now work without any external process feedback, this is beginning to change rapidly with the development of improved low cost sensor systems and methods. Virtually all robots are capable of discrete digital and analog signal input and output. Most may also be equipped with standard serial and parallel communication capacity. If sensor information is to be used for set-up positioning or real-time path adjustment, the robot controller must have the communication and control to convert data into information that can be used to modify path and position commands. In cases of extreme path complexity, path planning systems external to the robot controller may be needed to create the paths. Testing will verify the ability of the robot controller to accept and execute externally generated motion sequence data. Industrial Applications of Process Robots
Palletizing and Depalletizing
Many products are packaged in boxes of regular shape and stacked on standard pallets for shipping. Robots are commonly used to palletize and depalletize boxes because they can be programmed to move through the array of box positions layer after layer. Although palletizing is more common than depal- letizing, there is no major functional difference in the manipulation requirements. Transport distances of several feet are common. Stack heights usually do not exceed 5 ft. Payload weight can be in excess of 100 lb. When standard servo-driven joint actuators are used accuracy and repeatability will usually be far better than the required box positioning precision.
Palletizing typically requires four axes of controlled motion — three for translation and a fourth for yaw to orient the box. Cylindrical coordinate robots are favored in palletizing because they have large vertical lift and a compact footprint allo wing more of the fl oor area in the workspace for conveyors and pallets. When larger workspace is needed gantry robots must be used. Continuous duty cycles are not uncommon and robot power is important for maximizing throughput. The most technically demanding aspect of system design is the gripper. V acuum grippers are popular for lifting boxes by their tops, but other more complex gripping methods are sometimes needed. Payloads must be carefully positioned
with respect to the robot’s wrist and other links to balance gravitational and dynamic loading. Load shifting during high acceleration moves can result in dropping or mislocating the box.
Palletizing position arrays are usually taught or programmed relative to a corner or keystone box position as a reference so that the entire array can be shifted by redefi ning that one position. Programs are simple and easily modifi ed to adapt to changes in box dimensions. Monitoring is done by checking the state of discrete proximity and vacuum sensors. A proximity sensor mounted on a gripper will indicate if an object is at an expected location; or the same simple proximity sensor may be used to stop the robot in the correct location to pick up a box from a stack of unknown height when the top of the box is encountered. V acuum pressure switches are often used to verify acquisition by suction cup. A simple proximity switch can be used to signal the presence of an expected package at the pick-up point. With careful timing and additional sensor inputs, items can be transported to and from moving conveyors. Packaging
Packaging is often a combination of palletizing and assembly-type actions. A collection of objects which may not be identical are inserted into a box or other container. The robot may also be required to assemble, place dunnage, seal, or mark the package. Insertion may simply require positioning the pack item over the opening of the package and dropping it. Boxes most often are supplied partially assembled, printed, and folded fl at. Usually human operators or a special machine will open and prepare the box for packing; rarely will the robot be used for this purpose. Often the robot can be used to place cardboard layer separators, foam, or cardboard holding forms and other protective dunnage in the box. Finally, sealing and marking operations may be performed by the robot. Pack items may require complicated assembly-type motions such as rotations and curved moves to clear other packed items.
Three to six axes of motion may be needed. Packing items with a variety of sizes, shapes, and other varying physical properties into one package have the potential to complicate motion and tooling requirements. Grippers can be designed with multiple functions or they can be designed to be exchanged by the robot at tool storage racks. When material throughput is high, a single robot may be dedicated to each pack item. Simple programming methods are employed such as teach programming. Discrete sensors are useful for monitoring grip status of pack items.
Machine T ending: Loading and Unloading
Forges, stamping process, some machine tools, and molding machines are now commonly tended by robots. Historically these types of machines have been loaded by human operators. Now these jobs are considered to be too arduous and hazardous. An important benefi t of robotic machine loading is improved product quality resulting from consistent machine cycles. Robots eliminate the inconsistencies of human- paced loading and as a result the cycle can be precisely repeated. For heated molding, stamping, and forging processes, part formation and release are sensitive to the thermal state of the machine. If a machine is left open for loading for differing amounts of time each c ycle, significant cooling v ariations result in potential sticking and geometric fl aws. When robots are used, the process can be tuned to the consistent robot loading cycle.
Machine loading is usually more demanding than other material handling applications because part orientation and placement are critical and may require locating mechanisms such as tooling pins and pads and/or sensor logic to guarantee interface between the robot and the serviced machine. Accuracy is usually not an important factor because the loading stations are permanently located in the robot workspace, but repeatability requirements may be as small as several thousandths of an inch. Payloads can range from a few ounces to several hundred pounds. Grippers for machine loading may also require tooling pins and pads to locate and orient parts and to mate precisely with the machine’s part holding fixture.The gripper may dock with the holding fi xture and then transfer the part when loading clearances are very tight.
The entire range of robot types, sizes, and confi gurations is used for machine tending. Articulated arm robots are needed when dexterous manipulation is required to transport parts through the maze of clamps and spindles and other protrusions and obstacles found on some machines or when part orientation
must change for loading. Applications where the robot is dedicated to loading a single part into a single machine in high volume production are not uncommon. Position programming is usually done by teaching. It is common to monitor discrete sensors in the gripper and the loaded machine to insure proper loading before cycling the process machine.
So rting
Discrete parts are often sorted during production, usually as a condition of transfer to the next production station. The sort characteristics are usually distributed in some unpredictable manner so that individual inspection and handling are required. The diflference between sorting and other transfer or loading robot applications is that the disposition of the part is based on information gained during the sort. The robot must have the programming functions to support multiple preprogrammed path execution triggered by the logical sort outcome conditions.
Pa rt Dipping
Many processes require controlled manipulation of parts temporarily submerged in some w orking fluid or coating material. Some common part dipping processes are the following.
Investment Casting. Intricately shaped and often delicate wax forms are coated with a slurry of stucco material which cures to form a mold. Later the wax is melted and drained from mold which can then be filled with molten metal. The dipping motion must be carefully controlled to prevent trapping bubbles and distorting the wax shape.
Solder Pretinning. Electrical contact pads and component leads are coated by dipping in molten solder as a preliminary step to assembly and soldering of the connections. A temperature-dependent fl ux reaction is required to achieve wetting by the solder so the robot must hold the component submerged in molten solder for a precise delay period. Speed of withdrawal is a major process variable for controlling the coating thickness of solder.
Conformal Protective Coating. Some electrical and mechanical components are dipped in liquid poly- mers to seal out moisture, air, and contamination. The viscosity of the polymer and the speed of insertion into the fluid must be controlled so that fl ow into small features occurs without trapping bubbles of air. Once submerged the component may be reoriented to several poses and to allow air bubbles to escape. Quenching. Heat treating is a commonly used method of improving alloy properties. V arious fluids are used as cooling baths. Controlling insertion and manipulation is important for control of cooling rate. Dipping processes require precision of part insertion and withdrawal so velocity and acceleration must be programmable and repeatable. The stirring requirements may require the use of a two- or three-axis wrist in addition to the translation motion axes. Grippers may require
special cleaning or cooling
capability either on board or at service stations located conveniently in the robot’s reach. Resistance Spot W elding
Dexterity, payload, and quickness are critical operational requirements for spot welding robots. Gun pose repeatability is critical for consistently locating weld joints. Access to joint locations is limited because both electrodes must reach the weld site while maintaining clearance between gun frame and workpiece edges. Large articulated arm robots are typically used for most spot welding applications because of the dexterity needed and because the weight of the welding gun and associated robot-mounted
apparatus often exceeds 200 lb. Fixed cycle programs are typical which may require several man-months to develop and less than a minute to execute. The robot spot welding path position names, path order, and control logic can be developed off-line, but lack of robot positioning accuracy characteristic of large articulated robots requires the weld positions for each individual robot to be taught by posing and recording them manually. This takes advantage of the robot’s repeatability which is often orders of magnitude better than its accuracy. Unfortunately, when a robot that has been teach programmed is replaced by another robot, even an identical model, hours or days of teaching will be required to bring the replacement robot on line. Practical new PC-based calibration methods which eliminate this problem by effectively improving accuracy are now becoming commercially available.
Drilling
Hole drilling is a precision machining process. Most robots cannot hold a drill spindle rigidly enough to overcome the drilling reactions and most robots cannot generally move in a precise enough straight line to feed the drill. Drilling robots use special drilling end effectors which locate and dock onto the w ork piece or a fi xture. The robot wrist and arm must be compliant and forceful enough to hold the drilling end ef fector firmly into location a g ainst the fixture or workpiece. Drilling end effectors have a spindle motor and a feed mechanism which execute a separately controlled drilling cycle while the robot holds the end effector in position.
The robot’s only contribution to the process is to move the drilling end effector into its docking or holding place. Drilling robots have been used most successfully in the aerospace industry because airframe structures require thousands of holes to be placed precisely and in complex orientations. Manipulability requirements for drilling are similar to those for spot welding. The drilling end effector weight will tend to be less than a welding gun but tool holding force and reach usually impose the requirement for large robots.
工业材料处理和工序机器人的应用
用机器人来代替人来完成工序经常导致失败。原因是机器人只是能够机械的复制而缺乏对工序的计划与控制能力。成千上万的机器人装置都失败了，由于用自动方法代替手动和不适应多变的相关工序。
人类操作人员一直是用他们的认识能力来完成这项工作。在过去或现在大量成功推行的机器人都具有共同的特点：重复执行固定的程序而很少做在线的路径和路点的修改。
工序机器人的计划与施行还通常需要高技术人员的努力，通常情况下，复杂的程序是耗时耗力的事情，连续的控制和多变的路径，平行复制对于即时工序控制来说难度很大，许多工序对于如何描述它们的控制算法，还没有得到充分认识。在一些应用中，传感器对于在环境中采用机器人计划而改变已变得越来越平常。机构、接合轨迹、定位、传递轨迹和对自动运行程序的绘制与完成等，由于传感器和计算机价格的持续降低而变得很实际。
在这个阶段机器人材料处理与工序应用着眼于自动系统中机器上的操作功能，操作被认为是制造材料的变换和工序转接的因素，程序和控制被视为制造工序中连接机器人操作的部分。
自动程序设计出发点是对将被自动化的工序全面理解，作为工序因素，工序机器人的施行需要着眼于操作。形位与路径的工序，要求对于使用的作者是独立的。做操作要求的静态空间分析，然后检测机械和动态要求是非常有用的，（在设计和选择工序机器人时）在工序中对工件和工件联系位置与定位的空间的描述提供了绘制要求操作的基础，工件画在一个合适的参考框架上，通常在工件的框架上，或是机器运载时，工件提升装置使用的地方。路径要求对于应用来说是次要的，路径不影响工序，连续路径工序的路径必需要绘制或标出，如果路径的连续分析描绘不可用一些沿着要求路径不连续点就会被路径占用的空间。这两者的结果就是被绘入形位与路径要求的笛卡尔坐标之中，还要包括对它们精度要求的描述，接下来机械和动态的要求就被定义出来。有效载荷与力反应在每个点，并沿着可以理解的路径之上。其它诸如加速度和能量等重要动态要求也算要以数量表示，操作要求是设计和选择机械手和机械控制器的基础。
工序机器人的操纵能力
完成操作工作的机器人的基本机械能力取决于他的机械结构，运动结构和驱动结构，有几种包括绘图、装载、点焊接、圆弧焊接等对于具体各种机械手臂的应用。
设计由工程需要逐渐形成，它们由设计安排好来完成一项特定的工程，这些机器人没有天生的工程能力，不能确保完成具体的应用。机器人的总体规格性质如手臂长度、重复能力、准确度和承载能力，在制造人员手册中有说明，与已出版的机器人说明书相比，一个完备定义的工程装置通常孤立机械领域其他有资格与之媲美者。很难描绘和评价一个机器人对于复杂动作的能力，精确的机器人工作轨道软件不被用户所知晓，只能被不正确的测试评价。加速度和装载能力通常是具体的，有一些明确路径的标准方法，但是机器人的动态行为和行动很难测量出来，具体行动测试通常用来要求证实工程机器人的操作能力。
操作控制与工序控制的一体化
时限操作与工序控制的一体化依靠机器人的程序和外部数据的输入与输出，任何要求的动作都能被执行，但程序不能太难以至于不实际。借助查说明书和作动作测试确保机器人具有完成协调动作的能力，举例说明作为一个程序的重要性，在一些复杂扭曲的圆弧缠绕的情况下，定义一个机器人工作路径，如果两个机器人拥有相同的动态结构和共同的轨道，程序却不同，就会导致其中一个有能力在用户定义的数学功能下执行路径，另外一个却只能执行近期空间位置的路径，在程序上的不同很容易又耗费成千上万个小时，对每一个遇到程序化的应用体，方法的可行性取决于要求的动作是否可以在实际的情况下可程序化，工序机器人外部数据的输入与输出变得越来越重要，尽管现在大多数机器人没有外部工程的反馈，但由于改进的低价传感器与系统的发展这些开始有了变化，实际上所有的机器人都有分离数字与模拟信号输入输出的能力，大多数可以装备标准的串行与并行通信接口，如果传感器信息被用来做位置确立或即时路径调整，机器人控制者必须使通信与控制端将数据转变成可以用来修改路径与位置的指令的信息。如果极端路径很复杂，机器人控制者外部的路径计划系统可能需要制作路径，测试将会证实机器人控制者接受和执行外部生成的动作与连接数据的能力。
工程机械的工业应用
装运与卸运
许多产品都被装入常归形状的箱子中，并堆放在标准运货盘上，机器人通常被用来装卸箱子，因为它们能用程序控制在一层层间的箱子行列中移动，尽管装运卸运更平常，但在操作要求中没有什么主要功能的不同，几英尺的运输距离很平常，堆放高度通常不超过5英尺，负重可以超过100磅，当标准伺服连接调节器运行时，准确度和可重复能力将会远高于要求的位置精度。
装载需要四种控制动作，三种用于平移，第四种用于偏移提起箱子。圆筒协调机器人适合于装运，因为它们有一个大的垂直升降器和一个允许在工作地有更多空间来运行的紧凑的轨道。当要求更大的工作空间时，构台机器人一定需要来使用。持续的功率运转很平常，对于最大化生产率机器人的能量很重要。系统设计最要求技术的环节是抓举能力，真空抓举法很容易将箱子举过头顶，但是其他更多的抓举方法有时需要更多。最大负载在机器人腕关节及其他连接处定好位，来平衡重力和动载荷。在高加速度移动情况下转换负载可导致箱子的坠落和位置放错。
装运位置行列通常以一个角落或拱心石处的箱子为参考点来编制程序，目的使整个行列都靠一点的重新定义而被转换。程序易于修改来适应箱子尺寸的变化，监视器是用检测分离呈度的感应真空传感器制成，在抓举器上安放的感应传感受器将会表明目标是否要一个期待的位置上，或者同样的普通感应传感器也许被用来使机器人停在一个正确的位置，当遇到其上面的箱子时，可以在一个未知的高度位置举起一个箱子。真空压力开关经常用来核对吸杯获得物，一个普通的感应开关可以被用来表示一个在抓举点的物体是否存在，仔细的调节时并用附加的传感器输入，物体能被移动的传递者运出和运回。
包装
包装通常是一种装运与装配型动作的结合，一定数量不相同的目标实体被插入到一个箱子或其他集装箱之中，机器人可能需要去装配，铺置衬板，密封或者标记包装品，插入这一过程一般需要对包装物的空隙进行定位并释放，箱子大多数都被进行部分的装配，印制，折叠平整，通常人类操作人员或一种特殊的机器将会打开准备包装，机器人很少被用作这种用途，机器人经常能够被用来布置纸板层分离器，泡沫塑料或者纸板支撑窗体和其他箱子中的保护衬板，
最后密封和标记的操作过程将用机器人来完成。包装各类项目需要复杂装配类型的动作，例如旋转和圆弧移动来跳过其他已包装完成的项目。
三到六轴的动作也许都需要，包装具有各种型号、形状和项目和其他变化的物理道具，成为一个包裹要有复杂动作的潜能要求和工具上的要求。夹持工具设计具有多种功能或者被设计或用来作为工具储运架的机器人交换装置。当材料生产量高的时候，一个单独的机器人也许被配备到每个包装项目。一般的规划方法被使用，例如教学规划、离散的传感器被用作监视各包装项目的控制情况。
机器管理：装载与卸载
铸造、冲压工序，一些机器工具和成型机器现今通常被机器人管理，从历史上来讲这些种类的机器曾经被人类操作人员装载。现在这些工作被认为太费劲与危险。机器人机器装载带来的重要便利，由于不间断的机器循环提高了生产质量。机器人终结了人类装配过程的间断步拍，结果使循环能够准确重复。如热处理、冲压和铸造工序，零件成型和释放对于机器的热状态很敏感，如果一个机器在每个循环的大量不同时间被打开，显著的冷却变化将导致潜在的粘结与几何循环缺陷。但当机器人被使用的时候，这些工序能被调整为不间断的机器人装载。
机器装载通常有更多要求比起其它的材料处理应用，因为部位方位与布置是很关键的并可能要求对机械装置定位。例如：工程定位销钉与衬垫和传感器逻辑来保证机器人和伺服机器之间的界面。精确度通常不是一个重要的因素，由于装载站被机器人的工作工间永久的定好位了，但是重复度要求可能还像千分之几英寸那样小。有效载荷的范围从几盎司到几百磅。机器装载的夹具也要求工程定位销钉定位其部分来同机器部分的支持结构准确配合。
机器人的种类、型号和配置的整体范围都被用作机器的管理。手臂关节机器人被使用。当灵巧的操作要求用来传递部件通过迷乱布置和夹具与心轴及其它建立在机器上的伸出物与障碍物或当一些部位位置必需为装载而改变。机器人被用于装载一个单独的部件到一个单独的机器上的应在高效生产上并不常见。位置程序常常被教学部分完成，人们常常监视在夹具上和被装载机器上的离散传感器以确保在机器工序前的合适装载。
分类
离散的部件经常在生产期间被分类，通常作为一种转移到下一个生产站的情况。分类的性质通常为一些不可预测的方式以致使人们需要对其进行单独的检查和处理。分类与其他转移或机器人装载应用的不同在于零件的部署是基于从分类期间获得的信息之上。机器人必须有此种程序功能来支持由逻辑分类输出情况产生的多重预编程序化执行路径。
零件的浸渍
许多工序都要求被控零件暂时浸在一些工作液或涂料之中，一些常见的零件浸渍工序如下。
覆盖式铸型
复杂的材料形状与精巧的蜡型件通常覆盖有一层可以生成铸型的泥浆。然后蜡熔化并排出将被熔化的金属填充铸型之外，这种浸渍运动一定要小心控制以防困住气泡或扭曲蜡型。
焊接与处理
电接触衬垫和成组的铅被浸入熔化的焊料所覆盖是焊接与装配环节中重要的一步。依靠温度作用的熔融反应需要使焊料变温。所以机器人必须确保组件浸泡在熔化的焊料之中。一定精确滞后的时间以内，退回的速控是一个主要的过程。由于被控焊料覆盖厚度的可变性。
淬火
热处理通常用在改进合金道具的方法上。各种各样的液体都在冷却池中被使用。对插入和操作的控制对控制冷却速率来说很重要，浸淬的工序要求零件插入志拔出的精确性，所以速度与加速度一定要可程序化和可重复化。除了解释动作的轴外，搅拌工作需要使用2到3轴的腕关节，夹具要求有特殊的清洁和冷却能力，既在工作板上又在服务站上方便定位于机器人的工作范围之内。
电阻点焊接
灵活性、承载能力与迅速性对于点焊接机器人来说是十分关键的操作要求。有权使接合点受到限制，因为在保持喷枪结构与工作地边缘之间清洁的同时两个电极一定要到达焊点。大关节连接的手臂机器人被特别的用在大多数点焊接应用中，由于灵活性的重要并且因为焊接喷枪和与机器人相关联器材的重量经常要超过200磅，固定的循环程序是很典型的，它可能需要几个人工作数
月来研发但执行时间却不超过一分钟。机器人的点焊接路径位置的名称，路径顺序和控制逻辑可以在线上研发。但是缺少机器人准确定位性质的大关节连接机器人要求焊接位置受每个单独的机器人的手动强制与记录。为取决于机器人的可重复性的优点，它通常是比准确性好的大量的命令。不幸的是，当一个被授于程序化的机器人被另外的机器人所取代，其它是一个相同的模型所取代它的，还需花耗数小时或数月的时间在线更换机器人指导方法。实际采用新型计算机核准方法借助于现在变得越来越值得节约利用的高效改进精度即解决了这个问题。
钻孔
钻孔是一道精确的机械工序。大多数机器人都不能足够严格的把持好钻头来克服钻孔的反应，并且大多数机器人都不能以一条足够精确的直线移动来满足孔的要求。钻孔机器人采用特殊的钻孔终端受动器，它被定位并且置于工作台或固定装置上。机器人的腕与手臂必须要足够顺从与有力来使钻孔终端受动器稳稳地进入附于固定装置与工作台的位置。
钻孔终端受动器有一个钻头的发动机和一个伺服机体，当机器人在一定位置把持终端受动器时，它负责执行一个独自的受控钻孔循环工作。
这种机器人只有助于将钻孔终端受动器移进其停靠并稳定的位置这道工序。钻孔机器人曾被大多数成功用在航天工业上，因为机身结构需要成百上千被精确布置和处于复杂方位的孔。钻孔操作要求同点焊接相似。钻孔终端受动器的重量一般要比一个焊枪轻，但是工具的受力和使用空间通常需要迫于使用大型机器人。
英语翻译例子
Translation Work 1 The evidence has gotten much stronger that a substance known as C-reactive protein may be every bit as important as cholesterol in the diagnosis and treatment of heart disease. Back in 2002, a thought-provoking study found that a blood test for C-reactive protein, called CRP, was actually better than the standard cholesterol test at predicting the risk of a heart attack or a stroke. Now two studies published in The New England Journal of Medicine have shown that drugs that reduce the levels of that protein in patients with severe heart disease can show the progression of atherosclerosis and prevent heart attacks and cardiac-related deaths. 更有力的证据证明一种被称作C反应蛋白的物质在诊断与治疗心脏疾病中有可能与胆固醇一样重要。早在2002年，人们在一个发人深省的研究中已发现血液C反应蛋白测试，即CRP，比胆固醇水平测试能更好地预测心脏病或中风的风险。现今，在《新英格兰医学期刊》中刊登的两则研究表明，用以减少患有严重心脏病的病人中的C反应蛋白水平的药物可以显示病者动脉粥样硬化的进展，并且该种药物还可以预防心脏病、降低因患与心脏相关疾病而死亡的风险。
英语常用翻译十二式
英语常用翻译十二式 英语翻译十二式(一) 同义反译法 例子： 1. Only three customers remained in the bar. 酒吧间只有三个顾客还没有走。(不译：「还留着」或「还呆在那里」) 2. I'll be here for good this time. 这一次我再也不走了。(不译：「永远在此呆下去」) 3. Please keep the fire burning when I'm out. 我不在家的时候，请别让炉子灭了。(不译：「我外出时，请让炉子继续烧着」) 4. "Wait, he is serious." 「等等，他不是说着玩儿的。」(不译：「等等，他是认真的。」) 5. "Now, Clara, be firm with the boy!" 「听我说，克拉拉，对这孩子可不能心软。」(不译：「……对这孩子要坚定」) (二) 删减解释词 例子： The traveller in the south must often have remarked that peculiar air of refinement, that softness of voice and manner, which seems in many cases to be a particular gift to the quotation and mulatto women. 到南方去的人看见那些黑白混血的女郎，准定会注意到她们十之八九都赋有那种独特的优雅风度、那种柔和的声调和文静的举止。 (三) 短句拆译 例子： " ...on one sunshiny morning in June , ..." 「在六月里的一天早上，天气晴朗，……」 (四) 译词推陈出新 例子：
时代周刊翻译
…Back to Sleep?: Why Are 2,500 U.S. Babies Still Dying of SIDS Each Year? ‘用背部睡觉’：为什么美国每年都有2500个婴儿死于婴儿猝死综合症 Putting babies on their back to sleep has dramatically reduced the number of SIDS deaths, but thousands of babies still die each year. A look at the key risk factors. 让婴儿用背部睡觉戏剧性的减少了婴儿猝死综合症的死亡数量，但每年还是有上千数量的婴儿死亡。这有一种对于关键的风险因素的看法。 There?s no doubt that the Back to Sleep campaign launched in 1994 to get parents to stop putting babies to sleep on their tummies has been a success. In the 1970s and 1980s, the rate of infant deaths per 1,000 live births was 1.5; it?s now 0.5. 无需置疑的是，1994年发起的用背部睡觉的运动，旨在阻止父母让婴儿用肚子睡觉是成功的。在20世纪70到80年代，婴儿死亡率为每一千名安全出生婴儿中有1.5，现在是0.5。 Within a generation, most babies are now put to bed on their backs, and yet 2,500 U.S. infants still die each year in the U.S. Researchers trying to understand why have noticed a curious byproduct of the trend toward back-sleeping: as fewer babies were being put to sleep on their bellies, more babies were documented engaging in other pediatric no-nos — sleeping with their parents, for example — which is another risk factor for SIDS. 在一代人中，大部分婴儿现在都用背部放在床上，但美国每年依然有2500个婴儿死亡。研究员正试图弄明白为什么人们会注意到用背部睡觉这种趋势的奇怪的副产品：越来越少的婴儿用腹部睡觉，越来越多的婴儿被证明参与到了一些儿科禁止的事情中——例如，和父母一起睡——这是婴儿猝死综合症的另一个风险因素。 A study published Monday in the journal Pediatrics takes a look at how risk factors for SIDS have evolved over the years. In an analysis of the 954 babies who died suddenly and unexpectedly in San Diego County between 1991 and 2008 — 568 of these deaths were attributed to SIDS — researchers found that
3英文文献及翻译格式示例
哈尔滨工业大学毕业设计（论文） 英文原文（原文也可以直接将PDF版打印） ASSESSING CREDIT OR DETERMINING QUANTITY? THE EVOLVING ROLE OF RATING AGENCIES Lynnette D. Purda* This version: April 21, 2011 Abstract Over the past ten years, credit rating agencies have come under intense criticism from both practitioners and academics, first for their failure to identify problems resulting in bankruptcies at Enron and Worldcom and second for providing overly optimistic ratings for structured finance products. While many investors question the value of rating agencies in light of these criticisms, they have proven remarkably resilient. This paper provides a brief background on how rating agencies secured competitive advantages in evaluating credit quality. It then reviews the empirical evidence on the information content of ratings given these advantages. I argue that the information content of ratings stems from two intertwined sources: 1) information related to credit quality and 2) information related to the firm’s ability to access debt. Based on this evidence, I suggest that the dominant role for ratings today is as a benchmark for financial contracting. In this way, ratings remain influential in establishing the supply and demand of debt securities. 译文 评级机构的发展的作用评估信用还是决定数量？ 本文：2011.4.21 摘要 在过去的十年，信用评级机构一直处于来自实践者和学者的激烈的批评中，首先他们未能发现问题，导致安然和世通破产；其次对结构性金融产品提供过于乐观的评级。虽然许多投资者因为这些批评对评级机构的价值提出了质疑，但他们仍然被证明是相当有活力的。这篇文章首先在评估机构如何在信用评级质量中获得竞争优势提供一个简单地背景介绍，然后考虑到这些优势回顾了一些信息内容方面的评级经验证据。个人认为信息内容的评级来自两种交织在一起（错综复杂）的来源：1）和信贷质量相关的信息；2)和公司获取债务资本能力相关的信息。以此为据，我建议当前评级的主导作用是作为基准的金融收缩。以这种方式，在建立债券的供应和需求方面评级仍然是有效的。 - -1
科学美国人的中文翻译
2012年1月4日星期三 雌激素是新的“利他林”吗？ ——性激素能让一部分女性思维敏捷，却也让一部分迟钝 大考即将来临？无法集中注意力？尝试一点雌激素吧。 加州大学伯克利分校的神经系统科学家在最近的一项研究中报道称，女性生理周期中的荷尔蒙波动可能会如咖啡因、甲基苯丙胺或最常见的兴奋剂利他林一样影响其大脑。 近年来的研究表明，工作记忆（短期信息处理能力）是依赖于化学物质多巴胺的。事实上，像利他林这样的药物可以模仿多巴胺帮助人们集中注意力。在老鼠身上的研究显示，雌激素似乎可以诱发多巴胺的释放。但是伯克利这次的新研究是首次把认识能力和人的雌激素水平联系起来，这也就解释了为什么有些女性会在她们生理周期的不同时间点有着或好或坏的认识能力。 这只研究团队对24名健康女性进行了检测。通过基因测试，她们中有些天然多巴胺水平高，而有些天然低。不出所料，多巴胺水平低的女性对于处理复杂的工作记忆问题有困难，比如将一串五个数字反着背出来。但当测试在排卵期中进行，雌激素水平最高时（一般是月经期的10~12天后）这些女性的表现显著改善，有大约10%的进步。令人惊讶的是，多巴胺水平天然高的女性处理复杂问题的能力，却在排卵期中雌激素水平最高的时候有很明显的下降。 根据组织此次研究的Ph.D Emily Jacobs说，脑中的多巴胺是“classic Goldilacks scenario”。对于多巴胺水平最低的25%女性来说，在月经期多巴胺水平的增加会增强她们的认识能力，而对于多巴胺水平最高的25%女性来说，月经期多巴胺水平的增加可能会使她们的多巴胺水平超过一个上限，从而减弱她们的认识能力。而剩下的50%女性都处在这两类女性水平之间，不在研究的范围内。 这项研究有着重大的意义。Jacob说，像咖啡因、利他林这种诱发多巴胺释放的药物对于特定时期的女性是无效，甚至是损害性的。而且，她还希望提醒科学家们注意，在研究脑部疾病时，男女大脑虽然天赋相同但是并不完全一样。 Jacob说，这之间有很大区别，只有我们能知道他们在正常状态下的区别，我们才能预测他们在疾病状态下的区别。 毁约——脑扫描揭示誓言什么时候会不被遵守 新郎说“我愿意”而又和别人有一腿的时候，他脑中发生了什么？朋友承诺还钱却一直不还，他的脑中又发生了什么？一项最新研究显示，毁约是一项很复杂的神经生物学事件。而且脑扫描可以在毁约发生前预测出谁将要毁约。 瑞士苏黎世大学的科学家运用核磁共振技术把大脑比喻成了一场投资游戏。投资者必须决定是否承诺与受托者分享利益。如果投资，会使得账户中的资金增加，但如果受托者选择不分享，结果也会是投资者受损失。几乎所有投资者都说会把钱给受托者，但最后并不会所有人都守约。 通过核磁共振的扫描，研究者可以在他们有机会毁约前预测出他们会不会毁约。毁约者脑部的一些区域的活动会更加活跃，包括分管在压抑诚实回应时自我控制的前额皮质层，和标志
英汉翻译经典例子及答案
1.Health is above wealth, for this cannot give so much happiness as that. 健康比财富更重要，因为财富不能像健康那样给人以幸福。 2.Here great disturbances at the heart of the earth caused mountains and volcanoes to rise above the water. For hundreds of years tiny coral creatures have worked and died to make thousands of ring-shaped islands called atolls （环礁）. 在那里，由于地心引力的剧烈干扰，一道道山脉，一座座火山升出水面。千百年来，微小的珊瑚虫在这里繁衍、死亡，形成了数不胜数的被称为环礁的环状岛屿。 3.Old lines and methods of communication do not work easily or efficiently with as much information as we now have. 由于我们今天的信息太多，那些旧的通讯线路和方法已不能灵便有效地处理他们了。 4. Scarcely can any law be made which is beneficial to all; but if it benefits the majority, it is useful. 法律难顾及所有人，于大多数人有利足矣。 5.The water spread out for miles in places in Kenya and Somalia, cutting off villages and forcing herders to crowd with their livestock onto a few patches of dry land. 在肯尼亚和索马里的某些地方，河水漫出河床，宽达数英里。洪水切断了村与村之间的联系，迫使牧民们和家畜挤在一起，困缩在一块块狭小的陆地上动弹不得。 6. The snow falls on every wood and field, and no crevice is forgotten; by the river and pond, on the hill and in the valley. 雪，在四处飘落着。雪花撒在树上，撒在田野里，撒在河边、湖畔、山上、谷底——没有一条岩缝墙隙里不飘满雪花。 7. When his door opened they saw a slender man of more than average height with gleaming eyes and a face so striking that it bordered on the beautiful.
英语四级翻译真题及范文答案2017 12
____年12月大学英语四级考试翻译题目 许多人喜欢中餐，在中国，烹饪不仅被视为一种技能，而且也被视为一种艺术。精心准备的中餐既可口又好看，烹饪技艺和配料在中国各地差别很大。但好的烹饪都有一个共同点，总是要考虑到颜色、味道、口感和营养(nutrition)。由于食物对健康至关重要，好的厨师总是努力在谷物、肉类和蔬菜之间取得平衡，所以中餐既味美又健康。 信息技术(Information Technology)，正在飞速发展，中国公民也越来越重视信息技术，有些学校甚至将信息技术作为必修课程，对这一现象大家持不同观点。一部分人认为这是没有必要的，学生就应该学习传统的课程。另一部分人认为这是应该的，中国就应该与时俱进。不管怎样，信息技术引起广大人民的重视是一件好事。 你要茶还是咖啡尿是用餐人常被问到的问题，许多西方人会选咖啡，而中国人则会选茶，相传，中国的一位帝王于五千年前发现了茶，并用来治病，在明清(the qing dynasties)期间，茶馆遍布全国，饮茶在六世纪传到日本，但直到18世纪才传到欧美，如今，茶是世界上最流行的饮料(beverage)之一，茶是中国的瑰宝。也是中国传统和文化的重要组成部分。 Would you like tea or coffee? That's a question people often asked when having meal. Most westerners will choose coffee, while the Chinese would like to choose tea. According to legend, tea was discovered by a Chinese emperor five
新时代英语传统文化翻译
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英文翻译范例
毕业设计（论文）英文翻译 课题名称 系 部 专 业 班 级 学 号 姓 名 指导教师 校内： 校外： 2012年4月5日
原文： CHARACTERISTICS OF COMPUTER INTRUSION AND KINDS OF SECURITY BREACHES CHARACTERISTICS OF COMPUTER INTRUSION AND KINDS OF SECURITY BREACHES 1．CHARACTERISTICS OF COMPUTER INTRUSION The target of a crime involving computers may be any piece of the computing system．A computing system is a collection of hardware，software，storage media，data，and persons that an organization uses to do computing tasks．Whereas the obvious target of a bank robbery is cash，a list of names and addresses of depositors might be valuable to a competing bank．The list might be on paper，recorded on a magnetic medium，stored in internal computer memory，or transmitted electronically across a medium such as a telephone line．This multiplicity of targets makes computer security difficult．In any security system，the weakest point is the most serious vulnerability．A robber intent on stealing something from your house will not attempt to penetrate a two-inch thick metal door if a window gives easier access．A sophisticated perimeter physical security system does not compensate for unguarded access by means of a simple telephone line and a modem．The “weakest point” philosophy can be restated as the following principle．
考研英语二2015到2017原文逐句翻译12篇
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地层时代中英文对照
圭亚那盆地地层时代中英文对照 Cainozoic 新生界 Tertiary 第三纪 Pleistocene 第三纪更新世 Miocene 第三纪中新世 Lower Miocene 第三纪下中新世 Oligocene 第三纪渐新世 Eocene 第三纪始新世 Middle Eocene第三纪中始新世 Lower Eocene第三纪下始新世 Paleocene 第三纪古新世、古近系 Cretaceous 白垩纪 Senonian 森诺阶 Campanian 坎帕阶 Santonian 桑托阶 Coniacian 科尼亚克阶（晚白垩纪第三期）Turonian 白垩纪土仑阶（晚白垩纪第二期）Cenomanian 森诺曼阶 Albian 阿尔比阶 Aptian 阿普第阶 Barremian 巴列姆阶 Precambrian 前寒武纪地层
Cainozoic 新生界 Quaternary 第四系Quaternary period 第四纪Paleocene 第三纪古新世、古近系 Mesozoic中生界 Cretaceous 白垩系 Jurassic 侏罗系 Triassic 三叠系 LateTriassicepoch 晚三叠世 Paleozoic 古生界 Permian 二叠系 LatePermianepoch Early Permian 早二叠世 Carboniferous 石炭系石炭纪 Late Carboniferous Devonian 泥盆系泥盆纪upperDevonionseries 上泥盆统 siluric 志留系Silurian 志留纪 Ordovician 奥陶系奥陶纪 Cambrian 寒武系寒武纪 Proterozoic era 元古代
中文地址英语翻译示例
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No. 272, Bayi Road, Nanyang City Henan Prov. China 473000 528400广东中山市东区亨达花园7栋702 李有财 Li Youcai Room 702, 7th Building Hengda Garden, East District Zhongshan, China 528400 361012福建省厦门市莲花五村龙昌里34号601室李有财 Li Youcai Room 601, No. 34 Long Chang Li Xiamen, Fujian, China 361012 361004厦门公交总公司承诺办李有财 Mr. Li Youcai Cheng Nuo Ban, Gong Jiao Zong Gong Si Xiamen, Fujian, China 361004 266042山东省青岛市开平路53号国棉四厂二宿舍1号楼2单元204户甲李有财Mr. Li Youcai NO. 204, A, Building NO. 1 The 2nd Dormitory of the NO. 4 State-owned Textile Factory 53 Kaiping Road, Qingdao, Shandong, China 266042
科学翻译
第12页 0903060136 梁潇 0903060137 黄浩 0901014108 黄瑞尧 5.3性能分析 通信开销：在和平时期，验证和密钥协商协议的要求只有三路之间的网状路由器和网络用户和双向沟通网络用户之间。这是最低的通信回合要实现相互认证，因此，和平招致降低认证延迟。此外，通过设计，和平带来最低的额外因为它们可能对网络用户的通信开销如掌上电脑和智能手机进行的移动客户端比其他笔记本电脑访问无线网状网。这些移动客户端要少得多强大相比，网状路由器考虑到他们的沟通能力。在消息（M.1），（M.1），（M.2），网络用户只需要发送一组签名履行认证功能。作为我们立足本集团上签字的变化计划[8]中提出，签名的包括两个G的元素五个元素的Z带够。当使用[19]中描述的曲线，可以首要采取p到170位并使用G组1，其中每个元素是171位。因此，总群签名的长度为1192位或149字节。有了这些参数，安全性是大致相同作为一个标准的1024位RSA签名，这是128个字节[8]。也就是说，群签名的长度几乎是作为一个标准的RSA-1024的签名相同。 计算开销：在和平，最昂贵的计算操作的签名生成和验证。签名生成需要两个同构的应用中。同构计算，需要大约同时，作为一个在G1幂（使用快速计算的轨迹图）[8]。因此，签名生成需要约八幂（或multiexponentiations）和两个双线性映射计算。验证签名需要六个幂和3+2|网址|双线性映射计算。按照设计，和平采用会话认证的不对称对称的混合方法，降低计算成本。网络实体（Mesh 路由器和网络用户）执行昂贵的组签名操作相互验证，只有当建立一个新的会话，所有同一会话的后续数据交换是通过高效的基于MAC的方法进行验证。 更具体地说，和平需要进行相互认证，为建立一个新的会话时，执行一个签名生成和签名验证的网络用户。由此可以看出，签名验证的实际成本计算取决于一致资源定址器的大小，而签名的发电成本是固定的。和平可以主动控制的一致资源定址器的大小。此外，可以采取一种更为有效的吊销检查算法，其运行的时间是一致资源定址器的独立[8]中描述了对用户的隐私有点牺牲。这种技术可以进一步带来的总成本六幂和5个双线性映射计算的签名验证。另一方面，和平需要一个网状路由器进行相互认证其覆盖范围内的每个网络用户每每灯塔消息不同的会议和标志定期播出。 存储开销：在和平中，网络用户可以携带资源约束的普及设备，如掌上电脑和智能手机访问的无线网状网。因此，存储每个网络用户的开销应该是负担得起的现代普及设备。在我们的计划显示说明，在和平中的每个网络用户需要存储两个信息：他的小组的私钥及相关系统参数。该组的私钥为每个用户包含1组元素的G1和2个Z元素。如果我们首要选择p到170位，并使用G组1每个组171位的元素，每个组私钥用户只需消耗511位的内存，这是微不足道的现代普及设备。大多数的内存消耗部分是系统参数，其中可能包括代码来形容双线性组（G
新编英语教程5(1-12)课文翻译
Unit 1 恰到好处 你见过一个笨手笨脚的男人往箱子上钉钉子吗？只见他左敲敲，右敲敲，说不准还会将整个钉子锤翻，结果敲来敲去到头来只敲进了半截。而娴熟的木匠就不这么干。他每敲一下都会坚实巧妙地正对着钉头落下去，一钉到底。语言也是如此。一位优秀的艺术家谴词造句上力求准确而有力地表达自己的观点。差不多的词，不准确的短语，摸棱两可的表达，含糊不清的修饰，都无法使一位追求纯真英语的作家满意。他会一直思考，直至找到那个能准确表达他的意思的词。 法国人有一个很贴切的短语来表达这样一个意思，即“le mot juste”, 恰到好处的词。有很多关于精益求精的作家的名人轶事，比如福楼拜常花几天的时间力求使一两个句子在表达上准确无误。在浩瀚的词海中，词与词之间有着微妙的区别，要找到能恰如其分表达我们意思的词绝非易事。这不仅仅是扎实的语言功底和相当大的词汇量的问题，还需要人们绞尽脑汁，要观察敏锐。选词是认识过程的一个步骤，也是详细描述我们的思想感情并表达出来使自己以及听众和读者深刻理解的一个环节。有人说：“在我思想未成文之前，我怎么知道自己的想法？”这听起来似乎很离谱，但它确实很有道理。 寻找恰如其分的词的确是件不容易的事。一旦找到了那个词，我们就会感到很欣慰：辛劳得到了回报。准确地用语言有助于我们深入了解我们描述的事物。例如，当有人问你：“某某是怎么样的人？”你回答说：“恩，我想他是个不错的家伙，但他非常……”接着你犹豫了，试图找到一个词或短语来说明他到底讨厌在哪里。当你找到一个恰当的短语的时候，你发觉自己对他的看法更清楚，也更精确了。 一些英语词汇词根相同而意义却截然不同。例如human 和humane,二者的词根相同，词义也相关，但用法完全不同。“ human action (人类行为)”和“humane action ( 人道行为)”完全是两码事。我们不能说“人道权力宣言”，而是说“人权宣言”。有一种屠杀工具叫“humane killer ( 麻醉屠宰机)，而不是human killer ( 杀人机器)。 语言中的坏手艺的例子在我们身边随处可见。有人邀请一名学生去吃饭，他写信给予回复。请看他的信是这样结尾的：“我将很高兴赴约并满怀不安（anxiety ）期待着那个日子的到来。”“Anxiety” 含有烦恼和恐惧的意味。作者想表达的很可能是一种翘首期盼的心情。“Anxiety” 跟热切期盼有一定的关联，但在这个场合是不能等同的。 乌干达一政党领袖给新闻界的一封信中有一句这样写道： 让我们打破这自私、投机、怯懦和无知充斥的乌干达，代之以真理，刚毅，坚定和奇异的精神。 这一激动人心的呼吁被最后一个词“奇异（singularity）” 的误用破坏掉了。我猜想作者真正要表达的意思是思想的专一，即抱定一个信念永不改变，咬定青山不放松，不被次要的目的干扰。而singularity 指的是古怪，特性，是将一个人从众多人中区分出来的那种东西。 即使没有出现词语误用，这词仍可能不是符合作者意图的恰如其分的词。一名记者在一篇有关圣诞节的社论中这样引出狄更斯的话： 任何有关圣诞节的想法和文字已经被禁锢(imprisoned )在这句话中……“Imprisonment” 暗示着强迫，威逼，这么一来似乎意思是有悖其初衷的。用“包含(contained )”或“归结（summed up ）”就要好些。“概括（epitomized）”也行，尽管听起来有点僵硬。稍微再用点心我们就能准确地找到“mot juste (恰倒好处的词) ”，那就是“distilled”.它比包含和归结语气更强。“Distillation (提炼)”意味得到本质（essence）的东西。因此我们可以进一步把这个句子修改为： 所有有关圣诞节的想法和文字的精华都被提炼到这句话之中。