英文翻译81

Industrial Robot and its system’s components

There are a variety of definitions of the term robot. Depending on the definition used, the number of robot installations worldwide varies widely. Numerous single purpose muchines are used in manufacturing plants that might appear to be robots. These machines are hardwired to perform a single function and can not be reprogrammed to perform a different function. Such single-purpose machines do not fit the definition for industrial robots that is becoming widely accepted. This definition was developed by the robot Institute ofAmerica:

A robot is a reprogrammable muhifunctional manipulator designed to move material, parts, tools, or specialized devices through variable progranmled motions for the perfommnce of a variety of tasks.

Note that this definition cxmtalns the words reprograrnmable and multifunctional. It is these two characteristics that separate the true industrial robot from the various single-purpose machines used in modern manufacturing firms. The term"reprogrammable"implies two things:The robot operates aec~)rding to a written program, and this program can be rewritten to acconlmodatc a variety of manufacturing tasks.

The term"multifunctional"means that the robot can, through reprogramming and the use of different cnd-effectors, perform a number of different manufacturing tasks. Definitions written around these two critical characteristics are becoming the accepted definitions among manufacturing professionals.

The fimt articulated arm came about in 1951 and was used by the U.S. Atomic Energy Commission. In 1954, the first programmable robot was designed by George Devol. It was based on two important technologies:

(1) Numerical control (NC) technology.

(2) Remote manipulation technology.

Numerical control technology provided a foma of machine control

ideally suited to robots.It allowed for the control of motion by stored programs. These programs contain data points to which the robot sequentially moves, timing signals to initiate action and to stop movement, and logic statements to allow for decision rfmking.

Remote manipulation technology allowed a machine to be more than just another NC machine. It allowed such machines to become robots that can perfoml a variety of manufactuing tasks in both inaccessible an unsafe environmonts. By mering these two technologies, Devol developed the first industrial robot, an unsophistieated programmable materials handling machine.

The first conunercially produced robot was developed in 1959. In 1962, the

first industrial robot to be used oil a production llne was installed by General

Motors Corporation. This robot was produced by Unimation. A major step forward

in robot control occurred in 1973 with the development of the T-3 industrial robot

by Cincinnati Milaeron. The T-3 robot was the first commercially produced industrial robot controlled by a minicomputer.

Numerical control and remote manipulation technology prompted the wide scale

development and use of industrial robots. But major technological developments

do not take place simply because of such new capabilities. Something must provide

the impetus for taking advantage of these capabilities. In the case of industrial

robots, the impetus was economies.

The rapid inflation of wages experienced in the 1970s tremendously increased the personnel costs of manufacturing firms. At the same time, foreign competition became a serious problem for U. S. manufacturers. Foreign manufacturers who had under taken automation on a wide scale basis, such as those in Japan, began to gain an increasingly large share of the U.S. and world market for manufactured goods, particularly automobiles.

Through a variety of automation techniques, includicg robots, Japanese manufacturers, beginning in the 1970s, were able to produce better automobiles more cheaply than nonautomated U.S. manufacturers. Consequently, in order to survive, U.S. manufacturers were forced to consider any technological developments

that could help improve productivity.

It became imperative to produce better produets at lower costs in order to

be competitive with foreign manufacturers. Other factors such as the need to find

better ways of performing dangerous marmfacturing tasks contributed to the

development of industrial robots. However, the principal rationale has always been,and is still, improved productivity.

One of the principal advantages of robots is that they can be used in settings

that are dangerous to humans. Welding and parting are examples of applications

where rotmts can be dangerous to humans. Even though robots are closely asmciated

with safety in the workplace, they can, in themselves, be dangerous.

Robots and robot cells must be carefully designed and configured

so that they do not endanger human workers and other machines. Robot work envelops should be accurately calculated and a danger zone surroundting the envelop clearly marked off. Red flooring strips and barriers can be userd to keep human workers out of a robot’s work envelope.

Eren with such precautions it is still a good idea to have an automatic shutdown system in situations where robots are used. Such a system should should have the capacity to sense the need for an automatic shutdown of operations. Fault-tolerant computers and redunant systems can be installed to ensure proper shutdown of robotics systems to ensure a safe environment.

Industrial robots is the science of designing, building, and applying industrial robcts. What are robots? In the late 1970s the Robotic Industries Association defined a robot as” a manipulator, designed to move material, parts,tools or specialized devices through variable programmed motions for the performance of a variety of tasks". Although this definition does not directly

include pick and place arms as robots, teleoperamrs and remotely controlled devicesare often referred to also as robots. The International Standards Organization(ISO) has a more lengthy definition of an industrial robot:

A machine formed by a mechanism including several degrees of freedom, often having tile appearanoa of one or several arms ending in a wrist capable of holding a tool or a workpiece or an inspection device. In particular, its control unit must use a memorizing device and .sometimes it can use sensing or adaptation appliances taking into account environment and circumstances. These multipurtpose machines are generally designed to carry out a repetitive function and can be adapted to other functions.

The RIA and ISO definitions both stress the muLtifunctional and

programmable capabilities and, therefore, exclude special-purpose "hard automation" tools and equipment typically found in high volume production. Also excluded are manual remote manipulators, which are extensions of human hands for use in, for example, sterile, hot, or radioactive environments.

In Japan, the Japanese Industrial Robot Association (JIRA) classifies industrial robots by the method of input informatkm and the method of teaching:

1. Manual Manipulators. Manipulators directly activated by the operator.

2. Fixed-sequence Robot. Robot that once programmed for a given sequence of operations is not easily changed.

3. Variable-sequence Robot. Robot that can be programmed for a given sequence of operations and can easily be changed or reprogrammed.

4. Playback Robot. Robot that "memorizes" work sequences taught by

a human being who physically leads the device through the intended work pattern; the robot can then create this sequence repetitively from memory.

5. Numerically Controlled (NC) Robot. Robot that operatas from and is controlled by digital data, as in the form of punched tape, cards, or digital switches; operates like a NC machine.

6. Intelligent Robot. Robot that uses sensory perception to evaluate its environment andcmake decisions and proceeds to operate accordingly.

The first-generation of robot systems was defined for the various robots with limited computer power. Their main intelligant functions include programming by showing a sequence of manipulation steps by a human operator using a teach box. Without any sensors, these robots require a prearranged and relatively fixed factory environment and, therefore, have limited use.

The second-generation of robot systems was enhanced by the addition

of a computer processor. A major step in industrial robotics development was the integration of a computer with the industrial robot mechanism. This has provided real-time calculation of trajectory to smooth the motions of the end effector and integration of mine simple force and proximity sensors to obtain external signals.

The main applications of second generation robots include spot and arc welding, spray painting, and some assembly.

Third-generation robot systems incorporate multiple eomputer processors and multiple arms that can operate asynchronously to perform .several functions. Distributed hierarchical mmputer organization is preferred, because it can coordinate motions and interface with external sensors, other machines, and other robots and can communicate with other computers. These robots can already exhibit intelligent behavior, including knowledge-based control and learning abilities.

Japan ranks as the world's top robot-producing and robot-using country, with more than 40% of the world's industrial robot installations. The reasons for this penetration are sociological-and technological factors that are unique to Japan:

industrial robots brought productivity and quality gains in Japanese industry, coupled with improvements of the work enviromnent. These have perpetuated the social-demand for more robots as well as increased the expectation from this technology.

Current and emerging robot applications in industry can be categorized on the complexity and requirements of the job. They range from simple, low technolngy pick-and place operations through medium technology painting, some assembly and welding operations to high technology precision assembly and inspection operations.

Pick-and-place Operations The earliest applications of robots were

in machine loading unloading, pick-and-place, and material transfer operations. Such robots typically were not servo controlled and worked with pneumatic or hydraulic power. The Icxad-carrying requirements were high, working in dirty or hazardous factory environments. Replacing unskilled human labor often in hazardous jobs, these robots had to be robust and low in initial and maintenance costs.

Painting and Welding Operations The next level in the sophistimtion of industrial robot applications was in spray painting, and spot and arc welding. These applications complemented or replaced certain skilled human labor. Often the justification was by eliminating dangerous environmental exposures. These applications often require tracking complex trajectories such as painting surface mntours, hence mrvo controlled "articulated or spherical robot structures were used.Lead-through teaching modes became commom, and sometimes sophisticated sensors are employed to maintain process consistency. Experience has shown that when properly selected and implemented, thase robotic applications usually lead to reduced overall manufacturing costs and improved product quality compared with manual method.

Assembly Operations The most advanced level of technology employing third-generation industrial robots is found in assembly. System repeatability is of utmost importance. End-of-arm tooling must be compliant, i.e., have both force and displacement control to adjust part insertions, which require that the robot actually "feel" its way along. This technology usually requires a measure of artificial intelligence. Assembly robots generally are electronically driven and operate in clean enviromnents. Assembly robots are expected to exceed further technology applications.

Other Applications Other typical applications of robots include inspection, quality control, and repair; processing such as laser and

water jet cutting and drilling, riveting, and clean room operations; and applications in the wood, paper, and food-processing industries. As industrial robot technology and robot intelligence improve even further, additional applications may be justified effectively.

The components of a robot system could be discussed either from a physical point of view or from a systems point of view. Physically, we would divide the system into the robot, power system, and controller (computer). Likewise, the robot itself could be partitioned anthropomorphically into base, shoulder, elbow, wrist, gripper, and tool. Most of these terms require little explanation.

Consequently, we will describe the components of a robot system from the point of view of information transfer. That is, what infomtation or signal enters the component; what logical or arithmetic operation does the component perform; and what information or signal does the component produce? It is important to note that the same physical component may perform many different information proees.sirkg operations (e. g. , a central computerperforms many different calculations on different data). Likewise, two physically separate components may perform identical information operations ( e. g., the shoulder and elbow actuators both convert signals to motion in very similar ways).

Actuator Asmciated with each joint on the robot is an actuator which causes that joint to move. Typical actuators are electric motors and hydraulic cylinders. Typically, a robot system will contain six actuators, since six are required for full control of position and orientation. Many robot applications do not require this full flexibility, and consequently, robots are often built with five or fewer actuators.

Sensor To control an actuator, the computer must have infommtion regarding the position and possibly the velocity of the actuator. In this context, the term position refers to a displacement from some

arbitrary zero reference point for that actuator. For example, in the case of a rotary actuator , "position" would really the angular position and be measured in radians.

Many types of sensors can provide indications of position and velocity. The various types of sensors require different mechanisms for interfacing to the computer. In addition, the industrial use of the manipulator requires that the interface be protected from the harsh electrical environment of the factory. Sources of electrical noise such as arc welders and large motors can easily makena digital system useless unless care is taken in design and construction of the interface.

Computation We could easily have labeled the computation module "computer,"as most of the Functions to be described are typically perfommd by digital computers. However, many of the Functions may be performed in dedicated custom hardware or networks of computers We will, thus, discuss the commputational component as if it were a simple computer, recognizing that tile need for real-time control may require special equipment and that some of this equipment may even be analog, although the current trend is toward fully digital systems.

One further note: We will tend to avoid the use of the term microprocessor in this book and simply say computer, although many current robot manufacturers use one or more microprocessors in their systems.

The computation component performs the following operations: Servo Given the current position and/or velocity of an actuator, determine the appropriate drive signal to move that actuator toward its desired position. "This operation must be performed for eaeh actuator. Kinematics Given the current statel of the actuators (position and velocity ),determine the current state of the gripper. Conversely, given a desired state of the hand, determine the desired state for each actuator.

Dynamics Given knowledge of the loads on the arm (inertia, friction,

gravity, acceleration), use this information to adjust the sorvo operation to achieve better performance.

Workplace Sensor Analysis Given knowledge of the task to be performed, determine appropriate robot motion commands. This nmy include analyzing a TV picture of the workplace or measuring and compensating for forces applied at the hand.

In addition to these easily identified co. mponents, there are also supervisory operations such as path planning and operator interaction.

中文翻译

工业机器人及其系统组成

有许多关于机器人这个术语的定义。采用不同的定义，全世界各地机器人的数量就会发生很大的变化。在制造T 厂中使用的许多单用途机器可能会看起来像机器人。这些机器是硬连线的，不能通过新编程的方式去完成不同的工作。这种单用途的机器不能满足被人们日益广泛接受的关于工业机器人的定义。这个定义是由美国机器人协会提出的：

机器人是一个以改编程序的多功能操作器，被设计涉及用束按照预先编制的、能够完成多种作业的运动程序运送材料、零件、工具或者专用设备。

注意在这个定义中包含“可以改编程序”和“多功能”这两个词。正是这两个词将真证的机器人与现代制造工厂中使用的单一用途的机器区分开来。“可以改编程序”这个术语意味着两件事：机器人根据编写的程序工作，以及可以通过重新编写程序来适应不同种类的制造工作的需要。

“多功能”这个词意味着机器人能够通过编程和使用的末端执行机构，完成不同的制造上作。围绕着这两个关键特征所撰写的定义正在变成制造业的专业人员所接受的定义。

第一个带有活动关节的于臂于1951年被研制出来，由美国原子能委员会使用。在1954年，第一个可以编程的机器人由乔治·狄弗设计出来。它基于下面两项重要技术：

(1)数字控制(NC)技术；

(2)远程操作技术。

数字控制技术提供一种非常适合于机器人的机器控制技术。它可通过存储的程序对运动进行控制。这些程序包含机器人进行顺序运动的数据，开始运动和停止运动的时间控制信号，以及做出决定所需要的逻辑语句。

远程操作技术使得一台机器的性能超出一台数控机器。它可以使这种机器能够在不容易进入和不安全的环________徉_境中完成各种制造任务。通过融合上述两项技术，狄弗研制出第一个机器人，它是一个不复杂的，可以编程的物料运送机器人。

第-台商业化生产的机器人在1959年研制成功。通用汽车公司在1962 年安装了第一台用于生产线上的工业机器人，它是尤尼梅森公刊生产的。在1973 年，辛辛哪挺·米兰克朗公司研制出T 3 工业机器人，存机器人的控制方面取得r 较大的进展。T 3 机器人是第一台商业化生产的采用计算机控制的机器人。

数字控制技术和远程操作技术推动了大范围的机器人研制和应用。但是主要的技术进步并不仅仅是由于这些新的应用能力而产生的，而是必须由利用这些能力所得到的效益来提供动力。就工业机器人而古，这个动力是经济件。

在 20 世纪70 年代中，丁资的快速增长大大增加了制造业的企业中的人工费用。与此同时，来自国外的竞争成为美国制造业所面临的一个严峻的考验。诸如日本等外国的制造厂家在广泛地应用自动化技术之后，其工业产晶，特别是汽车，在美国和世界市场上占据了日益增大的份额。

通过采用包括机器人在内的各种自动化技术，从20世纪70 年代开始，口本的制造厂家能够比没有采用自动化技术的美国制造厂家生产更好的和便宜的汽车。随后，为了生存，美国制造厂家被迫考虑采用任何能够提高生产率的技术。

为了与国外制造厂家进行竞争，必须以比较低的成术，生产出更好的产品。其他的因素，诸如寻找能够更好地完成带有危险性的制造工作的方式也促进了工业机器人的发展。但是，主要的理由一直是，而日．现在仍然是提高生产率。

机器人的一个主要优点是它们可以在对于人类来说是危险的位置上工作。采用机器人进行焊接和切断工作是比由人工来完成这些工作更安全的例子。尽管机器人与工作地点的安全密切相关，它们本身也可能是危险的。

应该仔细地设计和配置机器人和机器人单元，使它们不会伤害人类和其他机器。应该精确地算出机器人的工作范围，且在这个范围的四周清楚地标出危险区

域。可以采用在地面上画出红颜色的线和设置障碍物以阻止工人进入机器人的工作范围。即使有了这些预防措施，在使用机器人的场地中设置一个自动停止工作的系统仍然不失为一个好主意。机器人的这个系统应该具有测出是否有需要自动停止工作的要求的能力。为了保证有一个安全的环境，应当安装容错计算机和冗余系统，保证在适当的时候停止机器人的工作。

工业机器人是一门设计、建筑、应用工业机器人的科学。什么是机器人呢？在20 世纪70 年代，机器人工业协会把机器人定义为“设计成可通过为实现各种各样任务而编制好的运动来移动材料、零件、工具或特别设备的操作者”。尽管这种定义没有直接把抓—放型手臂算作机器人，但远距离操纵装置和遥控装置通常被认为是机器人。国际标准组织有一个更合法的工业机器人的定义：一种含有多层次自由度的机器，通常用一条或多条手腕的末端来握住一个工具或一个部件或检测装置。特别地，它的控制单元必须用一个记忆设备，考虑到环境和条件等因素

通常可用检测或适应装置，这些多用途的机器通常设计为实现重复性功能，同时也可适用于其他功能。机器人工业协会和国际标准组织都强调多功能和程序化的功能。因此，包括特殊用途“硬自动化”工具和装置特别地出现在高档产品。同时也包括远途手动操作者，它们是人类工作在如枯燥无味的、热的、辐射性的环境里应用的延伸。

在日本，日本工业机器人协会根据输入信息和示教方法的不同把工业机器人分为：

1、手动操作者操作者直接由操作人操纵。

2、固定顺序机器人这类机器人一旦被给定某执行顺序的程序，就不容易改变。

3、可边顺序机器人可以对这类机器人进行编程，使其按一定的顺序工作，可以很容易地改变这种顺序或者重新编程。

4、再现式机器人这种机器人的记忆工作顺序由人的示教，他通过已定的工作类型亲自引导设备来实现。这种机器人可以由记忆重复实现这种顺序。

5、数字控制机器人这种机器人由数字化数据来操作和控制，这些数字数据有针孔带、记忆卡、或数字表等形式，像一台数字控制机器操作。

6、智能机器人这种机器人采用感官知觉对它周围的环境进行评价和做出决定，并据此进行工作。第一代机器人系统被定义为许多带有有限计算机能力的机器人，他们主要的智力功能包括通过由操作人员用一个示教盒来显示出一系列的操作步骤的程序。没有任何传感器，这些机器人需要一个预先设计，直接与工厂相应的环境。因此，其应用的场所很有限。

第二代机器人系统的功能由于增加一个计算机程序而加强。其在工业机器人发展中的关键步骤是将一台计算机与工业机器机构相集合。这样就提供实时的轨迹计算。可以使末端作用器的运动更为平滑，并且集成了某些简单的力传感器和接近式传感器以获取外部信号。第二代机器人的主要应用包括勘测、焊接、喷漆和其它一些的组合。

第三代机器人系统包括多层次计算机程序和多层次手臂，它能自如地实现多种功能。分配多层次计算机组织为首选，因为它能协调各种运动并且可以与外部传感器、其他机构和其他机器人相联接，并且可以和其他计算机相联系。这些机器人可展示智力行为，包括在知识基础上的控制和学习能力。

日本作为世界顶尖的机器人制造和使用的国家，拥有高达40%以上的世界工业机器人装置。其原因为这种集中是由于日本独特的社会和科技因素：工业机器人在日本工业中带来了高生产率和高质量产品，并与其工业的环境的提高相匹配，这些因素使得社对更多的机器人的需求被无限期地延续下去和增加了人们对这种技术的期望。现行的和正在开发的机器人在工业上的应用可由其复杂程度和工作的需求的不同而分类。它们可分为从通过中介技术图案简单的、低技术抓—放型操作，一些组合和焊接操作到高技术高精度的组合检测操作。

抓—放型操作机器人最早的应用为在机器装、卸载，抓、放和材料转运的操作。这

种机器人典型地不是传输控制和用压缩气体或气动能量来工作。它的载荷运作要求很高，工作在有脏又危险的工厂环境中。这些机器人通常被用来替代从事危险性工作的非技术工

人，它们必须坚固而且具有较低的使用费用和维护费用。

喷漆和焊接操作工业机器人复杂应用的下一水平为喷漆、勘测和焊接。这些应用实施或代替一些技术工业的劳动力。通常需要跟踪复杂轨迹如图案表面轮

廓，因此，控制铰接或关节型机器人被选用。示教型这种方式变得比较常见，有时还需要复杂的传感器来保持过程的一致性。经验显示当合理选择和实施时，与人工方法相比应用这些机器人通常能降低整个制造成本和提高产品的质量。

装配操作技术应用第三代工业机器人的最高水平是装配的重复性能为最重要时，臂切削端必须是顺从的，例如，有两个力和位移控制来调整部件选用，它需要机器人能实际地感觉到它的距离。这种技术通常需要一个人工智能的手段。组装机器人通常由电子驱动逼供内在洁净的环境中工作，组装机器人有望于超出低技术应用。

其他应用机器人其他典型的应用包括检测、质量控制，和修复；过程如激光和水枪切、钻和清扫屋舍操作；和在木业，纸业和食品制造业的应用。作为工业机器人技术和机器人智力的提高甚远，附加的应用也可被视为有效的。

可以从物质的观点电可以从系统的观点，讨论机器人系统的组成部分。从物质上看我们可以将系统分成机器人、电源系统和控制器(计算机)。机器人本身可以像人一样被分为基座、肩、肘、腕、抓持器和工具。这此术语中的大部分不需要做任何解释。

因此，我们将根据信息传递的观点来描述机器人系统的组成部分。也就是，什么信息或者信号进入计算机的组成部分，这个组成部分进行何种逻辑或者算术运算，这个组成部分产生什么信息或者信号?成该认识到，同一个组成部分可以完成许多不同的信息处理工作(例如，中心汁算机可以根据小同的数据进行许多不同种类的计算)，这一点是很重要的。与之相似，在结构上分开的两个组成部分可以进行相同的信息操作(例如，肩部和肘部的执行机构用非常相似的方式将信息转换为运动)。

执行机构执行机构与机器人的每个关节相连，并且驱动这个关节进行运动。电动机和液压缸都是典型的执行机构。由于对位置和方向进行完全控制需要六个变量，通常一个机器人系统需要六个执行机构。在实际应用中，许多机器人并不需要具有这种完全的灵活性，因此，机器人通常只有五个或更少的执行机构。

传感器为了控制执行机构，计算机内须有关于执行机构位置的信息，还可能有执行机构速度的信息。这里所说的位置是指执行机构相对任意零参考点的位移。例如在转动装置中，“位置”为角度的位置，并且采用弧度为单位来对其进

行度量。

许多种类的传感器能够表示位置和速度。各种传感器要有不同的机构作为它与计算机之间的连接装置。此外，操纵型机器人在工业中的应用要求对这种连接装置加以保护，使其免受工厂中的恶劣电气环境的影响。如果在设计和制作时没有认真考虑对数字系统的连接装置加以保护，诸如电弧焊机和大电动机所产生的电气噪声源可以很容易地使这个数字

系统失去作用。

计算部分我们可以容易地将计算模块称为计算机，这是凶为将要描述的大部分功能通常是由数字计算机完成的。然而，许多功能也可以由专用的硬件或者计算机网络来完成。应该认识到在要求进行实时控制时，可能需要专门的设备，尽管目前的趋势是向着全数字化发展，这个设备的某些部位甚至还可能采用模拟方式。在这里，将把计算部分当做一个简单的计算机来讨论。

进一步的说明：尽管许多机器人制造厂家目前在他们的系统中使用一个或者几个微处理器，在本书中我们避免使用微处理器这个术语，简单地将其称为计算机。计算部分可以完成上述工作。

伺服已知执行机构当前的位置和／或速度，确定使执行机构向着它预定的位置运动的驱动信号。对于每个执行机构都需要进行这种控制。

运动学已知执行机构目前的状态(位置和速度)，确定抓握器当前的状态。相反地，已知于的一个期望状态，确定每个执行机械的期望状态。

动力学已知机器人臂的负载信息(惯量、摩擦、加速度)，利用这种信息对伺服机构进行控制，以取得更好的工作特性。

在工作地点进行传感器信息分析已知需要完成任务的信息，确定适当的机器人运动指令。这可能会包括对工作场所的电视图像的分析，或者对手部施加的力的测量和补偿。

除了这些容易确定的组成部分，还有一些监督管理工作，例如路径设计和操作者的干涉。