机械设计制造及其自动化外文翻译--机器人

1、. 本科生毕业设计 (论文)外 文 翻 译原 文 标 题Robotics译 文 标 题机器人作者所在系别机械工程系作者所在专业机械设计制造及其自动化:- 1 -译文标题机器人原文标题Robotics作 者Darrick Addison译 名Darrick爱迪生国 籍美国原文出处U.S. Robotics Society Press译文：机器人机器人应用 许多今天使用的机器人在做一些对工人特别困难的工作.这些类型的工作需要很大的力量,或者有危险.比如,在需要将汽车零件焊接在一起的自动生产工业中,机器人就特别有用,工人使用的焊接工具重约100磅,或更重,并且很难操作。作为机械巨人,机器人可以被呼唤

2、去做任何事情,从一工场的工作站点之间移动笨重部件到到运送袋装的水泥。由于机器人不需要呼吸，所以喷涂是另一个适合机器人的任务，不像油漆工，机器人不受有毒气体的影响。机器人更优于完成这种工作，不但因为它们比人做得更快更便宜，而且因为能在人不能工作的地方进行工作。适合于机器人工作中，第三个项目是装配电子元件。机器人能很好地将芯片装配在印刷电路板上，因为它具备人所没有具备的能力。一旦适当地编程，机器人就不会将芯片放错地方。这种自动的精度在这种类型的工业中特别有价值，因为定位和安装错误代价是很高的。机器人革命早期的机器人又瞎又聋，但新型机器人安装有电视摄像机和其他传感设备，因而能感知热、结构、尺寸和声音

3、，这些机器人用于空间计划、核反应堆和水下探测研究。在扩大机器人应用范围的尝试中，研究者正超越传统设计，并考虑源自生物世界的各种潜在模型，工业机械手是一个典型的例子。科学家已能让机器人模仿蛇的脊椎，以油漆汽车内部。在着力建造能举起重物体的机器人的手臂时，他们模仿肌肉结构和大象鼻子的运动。科学家还模拟章鱼的灵活性，其触角能用于任何形状的易碎品，并用均匀且轻柔的压力握住这些易碎品。这种设计的一种变化能用于抱起动物，给医院中病床上的病人翻身，或抱起小孩。机器人有在工厂或实验室外独立操作的技能，这一挑战已花费了学术界、军世界和工业界的科学家们的智谋和创造性。简单来说，机器人的手如同机器人的腿、眼睛或推理

4、能力。在接近经过成亿年生物进化所获得的能力之前，还有很长的路要走。在机器人能和自然的杰作相比之前，在世界各地的实验室中还需完成许多工作。同时，机器人的进展已开始转变人所做的工作，令人厌烦和危险的工作已由机器人承担。在世纪之交，更多更多的人要去完成机器所不能完成的任务。已有许多工业家希望到2000以后，所有的雇员都是知识工，不再站在装配线前，而是坐在桌子和计算机终端前处理信息。这些变化已经存在，而且其步伐每年都在加快。智能机器人一个机器人应用中的新局面随着“智能机器人”的发展而已经打开。一个智能机器人基本上能感知环境并且具有足够的智力，像我们人一样能对变化的环境作出响应。这种能力要求直接使用感觉

5、和人工智能。许多机器人的研究已经，并且仍然关注如何在机器人中装备视觉传感器眼睛和触觉传感“手指”。人工智能将使机器人能响应并适应其工作任务和环境变化，并且能按照这些变化的反应进行推理和作出决定。视觉传感为使机器人模仿人的感觉能力，已作了很多的努力。其中，视觉是最重要的感觉，因为据估计，接近80的感觉信息是由视觉收到的。机器人系统中设置视觉可由各种形式的图象传感器来完成。为了改善运行的精度，通过视觉传感器的光学反馈控制，可精密地调整机器人手臂。决定位置、方向和辨别所要选取得零件则是另一重要的应用。在视觉系统中，关键部件之一是图象传感器。机器人系统中的图象传感器的定义为将光学图象转换成视频信号的电

6、光学器件。图象传感器通常为电视摄像机，或固态传感器件，如电荷耦合器件（CCD）。后一种器件提供更高的灵敏度、较长的耐久性和较轻的重量，因而与电视摄像机相比更受欢迎。摄像系统不但包括摄像探测器，而且更重要的是包括光学透镜系统。这种透镜决定视场、定焦深度和其他直接影响摄像机所摄图象质量的光学特性。无论电视摄像机还是CCD都会通过在每一象素点形成与光强成正比的模拟量而产生图象。要使数字计算机对信号起作用，需要模拟数字（A/D）转换器将模拟数据转换成数字数据，然后存储在计算机内的随机存取存储器（RAM）中。计算机分析这些数据并抽取某些信息，如边界、区域、颜色，以及图象中物体结构。最后，计算机能就场景的

7、辨别、理解图象所表示的含义或作出解释，并使机器人用符号对环境的描述。接触感觉重要性仅次于视觉是接触感觉，或触感。想象一下盲人能依靠灵敏的触觉来做精细的工作。无视觉机器人能只用触觉极有效地完成装配任务，对于需要反馈来紧紧握住精致脆弱的物体而不会损坏它们的用途，触觉具有独特的重要性。为了模拟人手的触觉，一完整的接触传感系统必须完成三个基本操作：（1）关节的力觉，检测加在机器人的手、腕和臂关节上的力；（2）触觉检测，加在手平面或者夹持器平面各个点上的压力；（3）滑觉，检测所抓取的物体的任何滑动。关节上的力通常用各种布置在机器人手腕零件上的应变测力计来检测。应变测力计是一种测力元件，其电阻变化与加在元

8、件上的力大小成比例。最简易的触觉传感器是用细小的微型开关阵列组成的夹持器。这种传感器只能决定物体是否在机器人手上的点阵中某个特殊点上存在。更为先进的触觉传感器使用压敏的压电材料（如导电橡胶或泡沫等）。其排列使传感器能感觉机器人手中的力和压力的变化。既然各点上的力可以决定，所以手掌面上的力就可被图象化地获得，并由此决定机器人手中所握物体的形状。对于产生一个用于精致脆弱物体的最佳握持力，机器人需要滑觉。这种能力避免损坏物体，并能抓起物体而不会有掉下的危险。夹持力一步一步增加，直至物体被紧紧抓住而不再有滑动。触觉和视觉的集成能极大地提高机器人的装配工作，这类传感器的一例是是觉传感器，用于对物体和机器

9、人本身的定位和辨别；并结合触觉传感器用于探测力和压力的分布和确定力矩、重量、重心，安所抓取的材料决定握持力。这种用于通用的手眼配合操作在工业界将会变得极为有效力。RoboticsThe Robotics Application Many of the robots in use tody do jobs that are especially difficult for human worker. These are the types of jobs that require great strength or pose danger. For example, robots are par

10、ticularly useful in the auto-manufacturing industry where parts of automobiles must be welded together. A welding tool used by a human worker weighs about 100 pounds or more and is difficult to handle. As mechanical supermen, robots may be called upon to do anything from moving heay components betwe

11、en workstations on a factory floor to carrying bags of cement. Spray painting is another task suited to robots because robots do not need to breathe. Unlike human painters, they are unaffected by the poisonous fumes. Robots are better at this task, not because they are faster or cheaper than humans,

12、 but because they work in a place where humans cannot. Third in the list of useful jobs for robots is the assembly of electronnic parts. Robots shine at installing chips in printed circuit boards because of a capability that robots have that people dont . A robot, one properly programmed, will not p

13、ut a chip in the wrong place. This automatic accuracy is particularly valuable in this kind of industry because locating and fixing mistakes is costly.Robotics Revolution Earlier robots were usually blind and deaf, but newer types of robots are fitted with video cameras and other sensing devices tha

14、t can detect heat, texture, size, and sound. These robots are used in space projects, nuclear stations, and underwater exporation research. Inther efforts to expand the range of robotic applications, reseachers are looking beyon traditional designs to examine a variety of potential models from the b

15、iological world. The industrial arm is a classic example. Scientists have been able to model robots to imitate the vertebrate spine of a snake in order to paint the interior of automobiles. They have simulated the muscle structure and movement of an elephants trunk in an attempt to create a robotic

16、arm capable of lifting heavy objects. Scientists also emulate the flexibility of an octopus where the tentacles can conform to the fragile objects of any shape and hold them with uniform, gentle pressure. A variation of this design can be used to handle animals, turn hospital patients in their beds,

17、 or lift asmall child.The challenge of equipping robots with the skills to operate independently, outside of a factory or laboratory, has taxed theingenuity and creativity of academic, military, and industral scientists for years. Simply put, robot hands-like robot legs, or eyes, orreasoning powers-

18、have long way to go before they can approach what biological evlution has achieved over by the course of hundreds of millions of years. Much more will have to happen in laboratories around the world before the robots can be compared to natures handiwork. In the meantime, the robotics revolution is a

19、lready beginning to change the kind of work that people do. The boring and dangerous jobs are now assumed by robots. By the turn of the century, more and more humans will be required for tasks that machine can not do. There are slso some industrialists who hope that by the year 2000 all their empoye

20、e will be knowledge workers, no longer standing on assembly lines but rather sitting at desks and computer terminals to deal with information. These changes are already under way, and their pace accelerates every year.Intelligent Robots A new phase in robot applications has been opened with the deve

21、lopment of “intelligent robots”. An intelligent robot is bascally one that must be capable of sensing its surrounding and possess intelligence enough to respond to a changing environment in much the same way as we do. Such ability requires the direct application of sensory perception and artificial

22、intelligence. Much of reseach in robotics has been and is still concerned with how to equip robots with visual sensors-eyes and tactile sensors-the”fingers”. Artificial intelligence will enable the robot to changes in its task and in its environment, and to reason and make decisions in reactiong to

23、those changes.Visional SensoryMuch effort has been made to simulate similar human sensory abilities for inelligent robots. Among them ,vision is the most important sense as it is estimated that up to 80% of sensory information is received by vision. Vision can be bestowed on robotic systems by using

24、 imaging sensors in various ways. For improving accuracy of performance, it can help precisely adjust the robot hand by means of optical feedback control using visual sensors. Determining the location, orientation, and recognition of the parts to be picked up is another important application.Among t

25、he vision system, one of the key components is imagery sensor. The imagery sensor of a robot system is defined as an electro-optical device that converts an optical image to a video signal. The image sensor is usually either a TV-camera or a solid state sensory device, for exanple, change-couple dev

26、ices(CCD). The latter device offers greater sensitivity, long endurance and lightweight, and is thus welcome when compared with the TV-camera. The camera system contains not only the camera detector but also, and very importantly, alens system. The lens determines the field of view, the depth of foc

27、ous, ans other optical factors that directly affect the quality of the image detected by the camera. Either TV-camera or CCDs produce an image by generating an analogue value on every pixel, proportional to its light intensity. To enable a digital computer to work with this signal, an analongue-to-d

28、igital(A/D) converter is needed to transfer analogue into digital data, then stored in random access menory(RAM), installed in computer. The computer analyzes the data and extracts such imagery information as edges, colors and textures of the objects in the image. Finally, the computer interprets or

29、 understands what the image represents in terms of knowledge about the scene and gives the robot a symbolic description of its environment.Tactile SensoryNext to vision in importance is tactile sensing or touching. Imagine the blind can do delicate jobs relying on his/her sensitive tactile. A blind

30、robot can be extremely effective in performing an assembly task using only a sense of touch. Touch is of particular importance for providing feedback necessary to grip delicate objects firmly without causing damage to them.To simulate tactile in human hands, a complete tactile-sensing system must pe

31、form three fundmental sensing perations: (1)joint force sensing which senses the force applies to robots hand, wrist and arm joints; (2)touch sensing which sense the preeure applied to various points on the hands surface or the grippers surface; (3)slip sensing which senses any movement of the objec

32、t while it is being graspeed.The joint forces are usually sensed using various strain gauges arranged in robotwrist assembly. A strain gauge is a force-sensing element whose resistance changes in proportion to the amount of the force applied to the element. The simplest application of touch sensor i

33、s gripper equipped with an array of miniature microswitches. This type of sensor can only determine the presence or absence of an object at a particular point or an array of points of the robot hand. A more advanced type of touch sensors uses arrays of pressure-sensitive piezoelectric material (conductive rubber or foam, etc.). The arrangement allows t