機(jī)器人1960 年初，約瑟夫·恩格柏格和喬治 ·迪沃爾聯(lián)合創(chuàng)建一個(gè)機(jī)器人公司——美國通用機(jī)械公司，從此工業(yè)機(jī)器人開始變?yōu)楝F(xiàn)實(shí)。機(jī)器人并不只是另一種自動(dòng)化機(jī)器。自動(dòng)化始于工業(yè)革命期間，用機(jī)器來完成先前人工完成的工作。然而，這種自動(dòng)化機(jī)器僅僅能做到為它設(shè)計(jì)的特定工作，而機(jī)器人能執(zhí)行各種各樣的工作。機(jī)器人必須有一對手臂。在裝卸自動(dòng)化機(jī)器、噴漆、焊接時(shí)，手臂必須能夠復(fù)制人類工人的動(dòng)作，并且能成千上百次完成傳統(tǒng)自動(dòng)化機(jī)器不能完成的工作。機(jī)器人的定義機(jī)器人工業(yè)協(xié)會(huì)(RIA)發(fā)表了一個(gè)機(jī)器人的定義，試圖闡明哪些機(jī)器僅僅是自動(dòng)化機(jī)械，哪些機(jī)器才是真正的機(jī)器人。RIA 的定義如下：機(jī)器人是一種可重新編程的多功能機(jī)械手，為實(shí)現(xiàn)各種任務(wù)設(shè)計(jì)成通過可改變的程序動(dòng)作來移動(dòng)材料、零部件、工具、或?qū)ｉT裝置。這個(gè)定義比本書末尾 RIA 術(shù)語匯編的定義更加廣泛，是更合適機(jī)器人的定義。當(dāng)我們看到這個(gè)短語的定義，我們會(huì)了解哪些機(jī)械是真正的機(jī)器人而哪些機(jī)械只是專用自動(dòng)化機(jī)器。首先，機(jī)器人是“可重編程的多功能操縱手” 。RIA 的這句話告訴我們，機(jī)器人可以通過改變其內(nèi)存中存儲(chǔ)的信息進(jìn)行示教（重編程）使機(jī)器人做不同的工作。可對機(jī)器人重新編程，使其裝卸自動(dòng)化機(jī)器、噴漆、焊接以及做許多其他的工作（多功能） 。機(jī)器人是“機(jī)械手” 。機(jī)械手是手臂（或手）可以拿起或移動(dòng)物品，在這一點(diǎn)上，我們知道，機(jī)器人是一個(gè)可以示教從而做各種不同工作的機(jī)械手臂。定義說，機(jī)器人“設(shè)計(jì)成通過可改變的程序動(dòng)作來移動(dòng)材料、零部件、工具、或?qū)ｉT裝置。 ”材料包括木材、鋼材、塑料、紙板在制造產(chǎn)品使用的任何材料。機(jī)器人也可以處理已加工完成的零部件。例如，機(jī)器人可以將一塊鋼裝入數(shù)控車床，并卸出車床中已加工完成的零件。除了處理材料和零部件，機(jī)器人還可以安裝如磨床、緩沖器、螺絲刀、焊槍等工具來執(zhí)行有效的工作。2在制造工廠中機(jī)器人也可以配備專門的儀器或設(shè)備來完成特殊的工作。機(jī)器人可以安裝攝像機(jī)來檢驗(yàn)零件或產(chǎn)品。也可以配備激光器來精確測量正在加工的零件的尺寸。RIA 的定義用“通過可改變的程序動(dòng)作來完成各種不同操作”這句話進(jìn)行結(jié)尾，這句話強(qiáng)調(diào)的事實(shí)是：在制造工廠，機(jī)器人可以做許多不同的工作。機(jī)器人能做的工作種類只受限于應(yīng)用工程師的創(chuàng)造性。機(jī)器人的工作由機(jī)器人完成的工作可分為兩大類：危險(xiǎn)性工作和重復(fù)性工作。危險(xiǎn)性工作許多機(jī)器人應(yīng)用于對人類有危險(xiǎn)的工作。這些工作因?yàn)橛卸練怏w、較重材料的處理、高溫材料的處理、在旋轉(zhuǎn)或沖壓機(jī)械旁工作或環(huán)境中含有高濃度的輻射而被認(rèn)為是危險(xiǎn)的工作。重復(fù)性工作除了擔(dān)任危險(xiǎn)的工作外，機(jī)器人也非常適合做那些在制造工廠里必須做的完全重復(fù)的工作。許多工廠的工作要求一個(gè)人表現(xiàn)得更像一個(gè)機(jī)器，而不像一個(gè)人類。這項(xiàng)工作可能要將一個(gè)工件從這里取起并把它放到那里。同樣的工作每一天都要做上百次。這個(gè)工作對判斷力和能力要求較少。這并不是批評(píng)做這份工作的人,而是僅僅指出這些工作存在于許多行業(yè)，并且必須完整的完成產(chǎn)品的制作。機(jī)器人可以在這樣的工作情況下工作，并且不會(huì)抱怨和經(jīng)受與這些工作相關(guān)的疲勞和厭倦。機(jī)器人的速度雖然機(jī)器人提高了制造工廠的生產(chǎn)率，但是他們也并不是很快。目前，機(jī)器人正常運(yùn)作速度或許已經(jīng)接近人類操作員的速度。機(jī)器人的每個(gè)主要運(yùn)動(dòng)通常需要大約 1 秒時(shí)間。對一個(gè)機(jī)器人來說,讓它們將一塊鋼從輸送機(jī)到裝載進(jìn)數(shù)控車床大約需要十個(gè)不同的動(dòng)作，這個(gè)動(dòng)作將耗費(fèi) 10 秒。人類操作員能在同樣的時(shí)間里完成相同的工作。生產(chǎn)力的增長是一致性的操作的結(jié)果。在工作期間人類操作員一遍一遍的重復(fù)同樣的工作，他或她就會(huì)慢下來。機(jī)器人在程序化的速度下連續(xù)的工作,因此在工作日內(nèi)能完成更多的零件。可以制造定制的自動(dòng)化設(shè)備做與機(jī)器人同樣的工作。這種定制的自動(dòng)化設(shè)備可以在3不到一半的時(shí)間里完成機(jī)器人或人們的裝載工作。問題是設(shè)計(jì)并制造這種特殊的機(jī)器,它只能完成特定的或定制的工作。如果在工作中有任何改變，這臺(tái)機(jī)器必須完全重建，或儀器必須報(bào)廢并設(shè)計(jì)制造另一臺(tái)新的機(jī)器。另一方面，機(jī)器人可以重新編程，并且在同一天就可以做新的工作。定制的自動(dòng)化設(shè)備在工業(yè)中仍然有一定的作用。如果公司知道一份工作多年來不會(huì)改變，盡快的定制自動(dòng)化機(jī)器仍然是一個(gè)不錯(cuò)的選擇。在工廠中有其他的一些定制的自動(dòng)化設(shè)備不能輕易的完成的工作。對于這些工作機(jī)器人可能是個(gè)不錯(cuò)的選擇。其中一個(gè)例子就是噴漆，它是一項(xiàng)具有危險(xiǎn)性的工作，因?yàn)閺脑S多油漆散發(fā)出來煙霧都是有毒和易爆的。現(xiàn)在由機(jī)器人來做外殼噴漆的工作。機(jī)器人已經(jīng)被“示教”進(jìn)行噴涂由公司制造的不同大小的外殼尺寸。另外，機(jī)器人可以在噴漆室這種有毒的環(huán)境下工作，從而毋須考慮這種煙霧對工作在室內(nèi)的人長期的影響。柔性自動(dòng)化機(jī)器人有另一個(gè)優(yōu)點(diǎn):“他們在制造工廠可以做不同的工作” 。如果機(jī)器人在最初購買是用于裝卸沖床并且這個(gè)工作在產(chǎn)品設(shè)計(jì)上不再需要改變時(shí),在工廠里機(jī)器人可以去做另一個(gè)工作。例如，它可以移到裝配操作的末端來卸載從輸送機(jī)運(yùn)輸來的已完成的附件，并放到貨盤出貨。準(zhǔn)確性和重復(fù)性機(jī)器人的一個(gè)重要特征是能準(zhǔn)確的完成其任務(wù)。當(dāng)機(jī)器人編制程序程以執(zhí)行特定的任務(wù)時(shí)，它被引導(dǎo)到確定特定的點(diǎn)并且編制程序來記錄所在點(diǎn)的位置，程序編制完成后，機(jī)器人轉(zhuǎn)向“運(yùn)行”并執(zhí)行程序?？上У氖?這個(gè)機(jī)器人不會(huì)走到所有程序設(shè)定點(diǎn)的準(zhǔn)確位置，例如，機(jī)器人可能會(huì)產(chǎn)生與確切點(diǎn) 0.025 英寸的誤差。機(jī)器人在第一次執(zhí)行點(diǎn)的計(jì)劃中，如果 0.025 英寸是最大誤差，就說明該機(jī)器人的精度為 0.025 英寸。除了準(zhǔn)確性，我們也關(guān)心機(jī)器人的可重復(fù)性。一個(gè)機(jī)器人的重復(fù)性是衡量其每次程序執(zhí)行后返回到與其程序點(diǎn)之間的位置接近程度。舉例來說,第一次執(zhí)行程序時(shí)，機(jī)器人產(chǎn)生 0.025 英寸的誤差，在接下來的執(zhí)行計(jì)劃中，機(jī)器人在到達(dá)這個(gè)點(diǎn)之前的循環(huán)會(huì)產(chǎn)生 0.010 英寸的誤差。雖然機(jī)器人共有 0.035 英寸的誤差。但從最初的編程點(diǎn)，其精度為 0.025 英寸，其重復(fù)性為 0.010 英寸。4機(jī)器人的主要部件機(jī)器人的主要部件有機(jī)械手、電源、控制器。機(jī)械手用來抓取制造中所需要的資料，零件，或特殊工具。電源提供機(jī)械手運(yùn)動(dòng)的動(dòng)力?？刂破饔脕砜刂齐娫矗箼C(jī)械手完成其任務(wù)。機(jī)器人的軸運(yùn)動(dòng)機(jī)器人機(jī)械手的不同運(yùn)動(dòng)形式是由機(jī)器人的自由度數(shù)或軸來定義的。如果機(jī)器人的機(jī)械臂可以旋轉(zhuǎn)，這個(gè)機(jī)器人可以稱為是一個(gè)單軸機(jī)器人。如果機(jī)械手可以上下移動(dòng)以及旋轉(zhuǎn)，機(jī)器人可稱為雙軸機(jī)器人。如果除了旋轉(zhuǎn)運(yùn)動(dòng)和上下運(yùn)動(dòng)，機(jī)械手也可以延長其手臂，或稱為“延伸” ，這個(gè)機(jī)器人可認(rèn)為是一個(gè)三軸機(jī)器人(如圖 24.1)。大多數(shù)工業(yè)機(jī)器人都有三個(gè)主軸運(yùn)動(dòng)(旋轉(zhuǎn)、上下、延伸)以及一些短軸運(yùn)動(dòng)。圖 24.1 有兩個(gè)線性軸和一個(gè)旋轉(zhuǎn)軸運(yùn)動(dòng)的三軸機(jī)器手機(jī)器人的短軸存在于機(jī)器人的手腕，機(jī)器人的手腕與機(jī)器人手臂的末端連接。機(jī)器人手腕有三個(gè)可能的運(yùn)動(dòng)或軸：俯仰、翻轉(zhuǎn)、偏轉(zhuǎn)（如圖 24.2） 。手腕上下彎曲是俯仰運(yùn)動(dòng)，手腕的轉(zhuǎn)動(dòng)是翻轉(zhuǎn)運(yùn)動(dòng)，手腕的側(cè)面運(yùn)動(dòng)偏轉(zhuǎn)運(yùn)動(dòng)。5圖 24.2 機(jī)器人手腕的三個(gè)自由度長軸與短軸的結(jié)合給了機(jī)器人六種能完成的動(dòng)作(六軸或六個(gè)自由度數(shù))。許多工業(yè)機(jī)器人裝配了所有的六軸，然而，其中有三個(gè)長軸，僅僅只有一個(gè)或兩個(gè)短軸。機(jī)器人的分類機(jī)器人的手臂末端可以達(dá)到的總面積稱為工作區(qū)間。根據(jù)其工作區(qū)間，機(jī)器人可以分為四類：圓柱坐標(biāo)機(jī)器人、直角坐標(biāo)機(jī)器人、球坐標(biāo)機(jī)器人和關(guān)節(jié)坐標(biāo)機(jī)器人。也可以按控制方式，將機(jī)器人分為三種運(yùn)動(dòng)形式：拾取和放置運(yùn)動(dòng)、點(diǎn)到點(diǎn)運(yùn)動(dòng)、連續(xù)軌跡運(yùn)動(dòng),這些術(shù)語描述機(jī)械手在其工作區(qū)間的動(dòng)作。本文摘選自“機(jī)器人及自動(dòng)化系統(tǒng)” ，羅伯特·L·胡克斯特拉，CmfgE，華南西部出版公司，1986 年。6Robots Industrial robots became a reality in the early 1960's when Joseph Engelberger and George Devol teamed up to form a robotics company they called “Unimation“.A robot is not simply another automated machine. Automation began during the industrial revolution with machines that performed jobs that formerly had been done by human workers. Such a machine, however, can do only the specific job for which it was designed, whereas a robot can perform a variety of jobs.A robot must have an arm. The arm must be able to duplicate the movements of a human worker in loading and unloading other automated machines, spraying paint, welding, and performing hundreds of other jobs that cannot be easily done with conventional automated machines.Definition of A RobotThe Robot Industries Association (RIA) has published a definition for robots in an attempt to clarify which machines are simply automated machines and which machines are truly robots. The RIA definition is as follows:A robot is a reprogrammable multifunctional manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks. This definition, which is more extensive than the one in the RIA glossary at the end of this book, is an excellent definition of a robot. We will look at this definition, one phrase at a time, so as to understand which machines are in fact robots and which machines are little more than specialized automation.First, a robot is a “reprogrammable multifunctional manipulator.” In this phrase RIA tells us that a robot can be taught (reprogrammed) to do more than one fob by changing the information stored in its memory. A robot can be reprogrammed to load and unload machines, weld, and do many other jobs (multifunctional).A robot is a “manipulator”. A manipulator is arm (or hand) that can pick up or move things. At this point we know that a robot is an arm that can be taught to do different jobs.The definition goes on to say that a robot is “designed to move material, parts, tools or Specialized devices“ material, includes wood, steel, plastic, cardboard…anything that is used in the manufacture of a product.7A robot can also handle parts that have been manufactured. For example, a robot can load a piece of steel into an automatic lathe and unload a finished part out of the lathe.In addition to handling material and parts, a robot can be fitted with tools such as grinders, buffers, screwdrivers, and welding torches to perform useful work.Robots can also be fitted with specialized instruments or devices to do special jobs in a manufacturing plant .Robots can be fitted with television cameras for inspection of parts or products. They can be fitted with lasers to accurately measure the size of parts being manufactured.The RIA definition closes with the phrase,“… through variable programmed motions for the performance of a variety of tasks.” This phrase emphasizes the fact that a robot can do many different jobs in a manufacturing plant .The variety of jobs that a robot can do is limited only by the creativity of the application engineer.Jobs for RobotsJobs performed by robots can be divided into two major categories: hazardous jobs and repetitive jobs.Hazardous JobsMany applications of robots are in jobs that are hazardous to humans. Such jobs may be considered hazardous because of toxic fumes, the weight of the material being handled, the temperature of the material being handled, the danger of working near rotating or press machinery, or environments containing high levels of radiation.Repetitive JobsIn addition to taking over hazardous jobs，robots are well suited to doing extremely repetitive jobs that must be done in manufacturing plants .Many jobs in manufacturing plants require a person to act more like a machine than like a human. The job may be to pick a piece up from here and place it there. The same job is done hundreds of times each day. The job requires little or no judgment and little or no skill .This is not said as a criticism of the person who does the job, but is intended simply to point out that many of these jobs exist in industry and must be done to complete the manufacture of products. A robot can be played at such a work station and can perform the job admirably without complaining or experiencing the fatigue and boredom normally associated with such a job.8Robot SpeedAlthough robots increase productivity in a manufacturing plant, they are not exceptionally fast. At present, robots normally operate at or near the speed of a human operator. Every major move of a robot normally takes approximately one second. For a robot to pick us a piece of steel from a conveyor and load it into a lathe may require ten different moves taking as much as ten seconds. A human operator can do the same job in the same amount of time. The increase in productivity is a result of the consistency of operation. As the human operator repeats the same job over and over during the workday, he or she begins to slow down. The robot continues to operate at its programmed speed and therefore completes more parts during the workday.Custom-built automated machines can be built to do the same jobs that robots do. An automated machine can do the same loading operation in less than half the time required by a robot or a human operator. The problem with designing a special machine is that such a machine can perform only the specific job, or which it was built. If any change is made in the job，the machine must he completely rebuilt, or the machine must be scrapped and a new machine designed and built .A robot, on the other hand, could be reprogrammed and could start doing the new job the same day.Custom-built automated machines still have their place in industry. If a company knows that a job will not change for many years, the faster custom-built machine is still a good choice.Other jobs in factories cannot be done easily with custom-built machinery. For these applications a robot may be a good choice .An example of such an application is spray painting. Spray painting is a hazardous job, because the fumes from many paints are both toxic and explosive. A robot is now doing the job of spraying paint on the enclosures. A robot has been “taught“ to spray all the different sizes of enclosures that the company builds. In addition, the robot can operate in the toxic environment of the spray booth without any concern for the long-term effect the fumes might have on a person working in the booth.Flexible AutomationRobots have another advantage: they can be taught to do different jobs in the manufacturing plant. If a robot was originally purchased to load and unload a punch press and the job is no longer needed due to a change in product design，the robot can be moved to another job in the plant. For example, the robot could be moved to the end of the assembly operation and be used to unload the finished enclosures from a conveyor and load them onto a 9pallet for shipment.Accuracy and RepeatabilityOne very important characteristic of any robot is the accuracy with which it can perform its task. When the robot is programmed to perform a specific task, it is led to specific points and programmed to remember the locations of those points .After programming has been completed, the robot is switched to “run“ and the program is executed. Unfortunately, the robot will not go to the exact location of any programmed point，F(xiàn)or example，the robot may miss the exact point by 0.025 in. If 0.025 in. is the greatest error by which the robot misses any point during the first execution of the program，the robot is said to have an accuracy of 0.025 in. In addition to accuracy, we are also concerned with the robot's repeatability. The repeatability of a robot is a measure of how closely it returns to its programmed points every time the program is executed. Say, for example, that the robot misses a programmed point by 0.025 in. the first time the program is executed and that, fluxing the next execution of the program, the robot misses the point it reached during the previous cycle by 0.010 in. Although the robot is a total of 0.035 in. from the original programmed point，its accuracy is 0 .025 in, and its repeatability is 0 .010 in.The Major Parts of a RobotThe major parts of a robot are the manipulator, the power supply, and the controller. The manipulator is used to pick up material, parts, or special tools used in manufacturing. The power supply supplies the power to move the manipulator. The controller controls the power supply so that the manipulator can be taught to perform its task.Axes of Robot MovementThe various movements that the manipulator of a robot can make are defined by its degrees of freedom or axes. If a robot’s manipulator can rotate, the robot is said to be a single-axis robot .If the manipulator can move up and down as well as rotate, the robot is called a two-axis robot. If in addition to the rotational movement and the up-and-down movement，the manipulator can also extend its arm, or “reach“, the robot is said to be a three axis robot(Fig.24.1).Most industrial robots have all three major axes(rotational, up and down, and reach) as well as some minor axes of movement.10Fig.24.1 Three-axis robot with cylindrical (post-type) manipulator, illustrating two linear axes, and one rotational axis, of movementThe minor axes of a robot are found in the robot's wrist, The wrist of a robot is attached to the end of the robot’s arm. These are three possible movements or axes of a rolx3t wrist: pitch, roll and yaw (Fig.24.2).The pitch movement bends the wrist up and down .The roll movement is the twisting of the wrist. The yaw movement is the side-to-side movement of the wrist. 11Fig.24.2 The three possible movements or axes of a robot wristThe combination of the major axes and the minor axes gives the robot six possible movements ( six axes or six degrees of freedom ).Many industrial robots are equipped with all six axes robots, however, have the three major axes but only one or two of the minor axes. Classification of RobotsThe total area that the end of the robot’s: arm can reach is called the work envelope. T Robots can be classified according to their work envelopes into four types: the cylindrical coordinate robot, the rectangular coordinate robot, the spherical coordinate robot, and the jointed arm coordinate robot. They also can be classified by motion control .There are three major classifications of motion for robots: pick-and-place, point-to-point, and continuous path. These terms describe the movements the manipulator can make within its work envelope,Selected from “Robotics and Automated systems”, Robert L. Hoekstra, CmfgE, South-Western Publishing Co, 1986.12教師評(píng)語教師簽名：機(jī)器人1960 年初，約瑟夫·恩格柏格和喬治 ·迪沃爾聯(lián)合創(chuàng)建一個(gè)機(jī)器人公司——美國通用機(jī)械公司，從此工業(yè)機(jī)器人開始變?yōu)楝F(xiàn)實(shí)。機(jī)器人并不只是另一種自動(dòng)化機(jī)器。自動(dòng)化始于工業(yè)革命期間，用機(jī)器來完成先前人工完成的工作。然而，這種自動(dòng)化機(jī)器僅僅能做到為它設(shè)計(jì)的特定工作，而機(jī)器人能執(zhí)行各種各樣的工作。機(jī)器人必須有一對手臂。在裝卸自動(dòng)化機(jī)器、噴漆、焊接時(shí)，手臂必須能夠復(fù)制人類工人的動(dòng)作，并且能成千上百次完成傳統(tǒng)自動(dòng)化機(jī)器不能完成的工作。機(jī)器人的定義機(jī)器人工業(yè)協(xié)會(huì)(RIA)發(fā)表了一個(gè)機(jī)器人的定義，試圖闡明哪些機(jī)器僅僅是自動(dòng)化機(jī)械，哪些機(jī)器才是真正的機(jī)器人。RIA 的定義如下：機(jī)器人是一種可重新編程的多功能機(jī)械手，為實(shí)現(xiàn)各種任務(wù)設(shè)計(jì)成通過可改變的程序動(dòng)作來移動(dòng)材料、零部件、工具、或?qū)ｉT裝置。這個(gè)定義比本書末尾 RIA 術(shù)語匯編的定義更加廣泛，是更合適機(jī)器人的定義。當(dāng)我們看到這個(gè)短語的定義，我們會(huì)了解哪些機(jī)械是真正的機(jī)器人而哪些機(jī)械只是專用自動(dòng)化機(jī)器。首先，機(jī)器人是“可重編程的多功能操縱手” 。RIA 的這句話告訴我們，機(jī)器人可以通過改變其內(nèi)存中存儲(chǔ)的信息進(jìn)行示教（重編程）使機(jī)器人做不同的工作?？蓪C(jī)器人重新編程，使其裝卸自動(dòng)化機(jī)器、噴漆、焊接以及做許多其他的工作（多功能） 。機(jī)器人是“機(jī)械手” 。機(jī)械手是手臂（或手）可以拿起或移動(dòng)物品，在這一點(diǎn)上，我們知道，機(jī)器人是一個(gè)可以示教從而做各種不同工作的機(jī)械手臂。定義說，機(jī)器人“設(shè)計(jì)成通過可改變的程序動(dòng)作來移動(dòng)材料、零部件、工具、或?qū)ｉT裝置。 ”材料包括木材、鋼材、塑料、紙板在制造產(chǎn)品使用的任何材料。機(jī)器人也可以處理已加工完成的零部件。例如，機(jī)器人可以將一塊鋼裝入數(shù)控車床，并卸出車床中已加工完成的零件。除了處理材料和零部件，機(jī)器人還可以安裝如磨床、緩沖器、螺絲刀、焊槍等工具來執(zhí)行有效的工作。2在制造工廠中機(jī)器人也可以配備專門的儀器或設(shè)備來完成特殊的工作。機(jī)器人可以安裝攝像機(jī)來檢驗(yàn)零件或產(chǎn)品。也可以配備激光器來精確測量正在加工的零件的尺寸。RIA 的定義用“通過可改變的程序動(dòng)作來完成各種不同操作”這句話進(jìn)行結(jié)尾，這句話強(qiáng)調(diào)的事實(shí)是：在制造工廠，機(jī)器人可以做許多不同的工作。機(jī)器人能做的工作種類只受限于應(yīng)用工程師的創(chuàng)造性。機(jī)器人的工作由機(jī)器人完成的工作可分為兩大類：危險(xiǎn)性工作和重復(fù)性工作。危險(xiǎn)性工作許多機(jī)器人應(yīng)用于對人類有危險(xiǎn)的工作。這些工作因?yàn)橛卸練怏w、較重材料的處理、高溫材料的處理、在旋轉(zhuǎn)或沖壓機(jī)械旁工作或環(huán)境中含有高濃度的輻射而被認(rèn)為是危險(xiǎn)的工作。重復(fù)性工作除了擔(dān)任危險(xiǎn)的工作外，機(jī)器人也非常適合做那些在制造工廠里必須做的完全重復(fù)的工作。許多工廠的工作要求一個(gè)人表現(xiàn)得更像一個(gè)機(jī)器，而不像一個(gè)人類。這項(xiàng)工作可能要將一個(gè)工件從這里取起并把它放到那里。同樣的工作每一天都要做上百次。這個(gè)工作對判斷力和能力要求較少。這并不是批評(píng)做這份工作的人,而是僅僅指出這些工作存在于許多行業(yè)，并且必須完整的完成產(chǎn)品的制作。機(jī)器人可以在這樣的工作情況下工作，并且不會(huì)抱怨和經(jīng)受與這些工作相關(guān)的疲勞和厭倦。機(jī)器人的速度雖然機(jī)器人提高了制造工廠的生產(chǎn)率，但是他們也并不是很快。目前，機(jī)器人正常運(yùn)作速度或許已經(jīng)接近人類操作員的速度。機(jī)器人的每個(gè)主要運(yùn)動(dòng)通常需要大約 1 秒時(shí)間。對一個(gè)機(jī)器人來說,讓它們將一塊鋼從輸送機(jī)到裝載進(jìn)數(shù)控車床大約需要十個(gè)不同的動(dòng)作，這個(gè)動(dòng)作將耗費(fèi) 10 秒。人類操作員能在同樣的時(shí)間里完成相同的工作。生產(chǎn)力的增長是一致性的操作的結(jié)果。在工作期間人類操作員一遍一遍的重復(fù)同樣的工作，他或她就會(huì)慢下來。機(jī)器人在程序化的速度下連續(xù)的工作,因此在工作日內(nèi)能完成更多的零件?？梢灾圃於ㄖ频淖詣?dòng)化設(shè)備做與機(jī)器人同樣的工作。這種定制的自動(dòng)化設(shè)備可以在3不到一半的時(shí)間里完成機(jī)器人或人們的裝載工作。問題是設(shè)計(jì)并制造這種特殊的機(jī)器,它只能完成特定的或定制的工作。如果在工作中有任何改變，這臺(tái)機(jī)器必須完全重建，或儀器必須報(bào)廢并設(shè)計(jì)制造另一臺(tái)新的機(jī)器。另一方面，機(jī)器人可以重新編程，并且在同一天就可以做新的工作。定制的自動(dòng)化設(shè)備在工業(yè)中仍然有一定的作用。如果公司知道一份工作多年來不會(huì)改變，盡快的定制自動(dòng)化機(jī)器仍然是一個(gè)不錯(cuò)的選擇。在工廠中有其他的一些定制的自動(dòng)化設(shè)備不能輕易的完成的工作。對于這些工作機(jī)器人可能是個(gè)不錯(cuò)的選擇。其中一個(gè)例子就是噴漆，它是一項(xiàng)具有危險(xiǎn)性的工作，因?yàn)閺脑S多油漆散發(fā)出來煙霧都是有毒和易爆的?，F(xiàn)在由機(jī)器人來做外殼噴漆的工作。機(jī)器人已經(jīng)被“示教”進(jìn)行噴涂由公司制造的不同大小的外殼尺寸。另外，機(jī)器人可以在噴漆室這種有毒的環(huán)境下工作，從而毋須考慮這種煙霧對工作在室內(nèi)的人長期的影響。柔性自動(dòng)化機(jī)器人有另一個(gè)優(yōu)點(diǎn):“他們在制造工廠可以做不同的工作” 。如果機(jī)器人在最初購買是用于裝卸沖床并且這個(gè)工作在產(chǎn)品設(shè)計(jì)上不再需要改變時(shí),在工廠里機(jī)器人可以去做另一個(gè)工作。例如，它可以移到裝配操作的末端來卸載從輸送機(jī)運(yùn)輸來的已完成的附件，并放到貨盤出貨。準(zhǔn)確性和重復(fù)性機(jī)器人的一個(gè)重要特征是能準(zhǔn)確的完成其任務(wù)。當(dāng)機(jī)器人編制程序程以執(zhí)行特定的任務(wù)時(shí)，它被引導(dǎo)到確定特定的點(diǎn)并且編制程序來記錄所在點(diǎn)的位置，程序編制完成后，機(jī)器人轉(zhuǎn)向“運(yùn)行”并執(zhí)行程序?？上У氖?這個(gè)機(jī)器人不會(huì)走到所有程序設(shè)定點(diǎn)的準(zhǔn)確位置，例如，機(jī)器人可能會(huì)產(chǎn)生與確切點(diǎn) 0.025 英寸的誤差。機(jī)器人在第一次執(zhí)行點(diǎn)的計(jì)劃中，如果 0.025 英寸是最大誤差，就說明該機(jī)器人的精度為 0.025 英寸。除了準(zhǔn)確性，我們也關(guān)心機(jī)器人的可重復(fù)性。一個(gè)機(jī)器人的重復(fù)性是衡量其每次程序執(zhí)行后返回到與其程序點(diǎn)之間的位置接近程度。舉例來說,第一次執(zhí)行程序時(shí)，機(jī)器人產(chǎn)生 0.025 英寸的誤差，在接下來的執(zhí)行計(jì)劃中，機(jī)器人在到達(dá)這個(gè)點(diǎn)之前的循環(huán)會(huì)產(chǎn)生 0.010 英寸的誤差。雖然機(jī)器人共有 0.035 英寸的誤差。但從最初的編程點(diǎn)，其精度為 0.025 英寸，其重復(fù)性為 0.010 英寸。4機(jī)器人的主要部件機(jī)器人的主要部件有機(jī)械手、電源、控制器。機(jī)械手用來抓取制造中所需要的資料，零件，或特殊工具。電源提供機(jī)械手運(yùn)動(dòng)的動(dòng)力?？刂破饔脕砜刂齐娫矗箼C(jī)械手完成其任務(wù)。機(jī)器人的軸運(yùn)動(dòng)機(jī)器人機(jī)械手的不同運(yùn)動(dòng)形式是由機(jī)器人的自由度數(shù)或軸來定義的。如果機(jī)器人的機(jī)械臂可以旋轉(zhuǎn)，這個(gè)機(jī)器人可以稱為是一個(gè)單軸機(jī)器人。如果機(jī)械手可以上下移動(dòng)以及旋轉(zhuǎn)，機(jī)器人可稱為雙軸機(jī)器人。如果除了旋轉(zhuǎn)運(yùn)動(dòng)和上下運(yùn)動(dòng)，機(jī)械手也可以延長其手臂，或稱為“延伸” ，這個(gè)機(jī)器人可認(rèn)為是一個(gè)三軸機(jī)器人(如圖 24.1)。大多數(shù)工業(yè)機(jī)器人都有三個(gè)主軸運(yùn)動(dòng)(旋轉(zhuǎn)、上下、延伸)以及一些短軸運(yùn)動(dòng)。圖 24.1 有兩個(gè)線性軸和一個(gè)旋轉(zhuǎn)軸運(yùn)動(dòng)的三軸機(jī)器手機(jī)器人的短軸存在于機(jī)器人的手腕，機(jī)器人的手腕與機(jī)器人手臂的末端連接。機(jī)器人手腕有三個(gè)可能的運(yùn)動(dòng)或軸：俯仰、翻轉(zhuǎn)、偏轉(zhuǎn)（如圖 24.2） 。手腕上下彎曲是俯仰運(yùn)動(dòng)，手腕的轉(zhuǎn)動(dòng)是翻轉(zhuǎn)運(yùn)動(dòng)，手腕的側(cè)面運(yùn)動(dòng)偏轉(zhuǎn)運(yùn)動(dòng)。5圖 24.2 機(jī)器人手腕的三個(gè)自由度長軸與短軸的結(jié)合給了機(jī)器人六種能完成的動(dòng)作(六軸或六個(gè)自由度數(shù))。許多工業(yè)機(jī)器人裝配了所有的六軸，然而，其中有三個(gè)長軸，僅僅只有一個(gè)或兩個(gè)短軸。機(jī)器人的分類機(jī)器人的手臂末端可以達(dá)到的總面積稱為工作區(qū)間。根據(jù)其工作區(qū)間，機(jī)器人可以分為四類：圓柱坐標(biāo)機(jī)器人、直角坐標(biāo)機(jī)器人、球坐標(biāo)機(jī)器人和關(guān)節(jié)坐標(biāo)機(jī)器人。也可以按控制方式，將機(jī)器人分為三種運(yùn)動(dòng)形式：拾取和放置運(yùn)動(dòng)、點(diǎn)到點(diǎn)運(yùn)動(dòng)、連續(xù)軌跡運(yùn)動(dòng),這些術(shù)語描述機(jī)械手在其工作區(qū)間的動(dòng)作。本文摘選自“機(jī)器人及自動(dòng)化系統(tǒng)” ，羅伯特·L·胡克斯特拉，CmfgE，華南西部出版公司，1986 年。6Robots Industrial robots became a reality in the early 1960's when Joseph Engelberger and George Devol teamed up to form a robotics company they called “Unimation“.A robot is not simply another automated machine. Automation began during the industrial revolution with machines that performed jobs that formerly had been done by human workers. Such a machine, however, can do only the specific job for which it was designed, whereas a robot can perform a variety of jobs.A robot must have an arm. The arm must be able to duplicate the movements of a human worker in loading and unloading other automated machines, spraying paint, welding, and performing hundreds of other jobs that cannot be easily done with conventional automated machines.Definition of A RobotThe Robot Industries Association (RIA) has published a definition for robots in an attempt to clarify which machines are simply automated machines and which machines are truly robots. The RIA definition is as follows:A robot is a reprogrammable multifunctional manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks. This definition, which is more extensive than the one in the RIA glossary at the end of this book, is an excellent definition of a robot. We will look at this definition, one phrase at a time, so as to understand which machines are in fact robots and which machines are little more than specialized automation.First, a robot is a “reprogrammable multifunctional manipulator.” In this phrase RIA tells us that a robot can be taught (reprogrammed) to do more than one fob by changing the information stored in its memory. A robot can be reprogrammed to load and unload machines, weld, and do many other jobs (multifunctional).A robot is a “manipulator”. A manipulator is arm (or hand) that can pick up or move things. At this point we know that a robot is an arm that can be taught to do different jobs.The definition goes on to say that a robot is “designed to move material, parts, tools or Specialized devices“ material, includes wood, steel, plastic, cardboard…anything that is used in the manufacture of a product.7A robot can also handle parts that have been manufactured. For example, a robot can load a piece of steel into an automatic lathe and unload a finished part out of the lathe.In addition to handling material and parts, a robot can be fitted with tools such as grinders, buffers, screwdrivers, and welding torches to perform useful work.Robots can also be fitted with specialized instruments or devices to do special jobs in a manufacturing plant .Robots can be fitted with television cameras for inspection of parts or products. They can be fitted with lasers to accurately measure the size of parts being manufactured.The RIA definition closes with the phrase,“… through variable programmed motions for the performance of a variety of tasks.” This phrase emphasizes the fact that a robot can do many different jobs in a manufacturing plant .The variety of jobs that a robot can do is limited only by the creativity of the application engineer.Jobs for RobotsJobs performed by robots can be divided into two major categories: hazardous jobs and repetitive jobs.Hazardous JobsMany applications of robots are in jobs that are hazardous to humans. Such jobs may be considered hazardous because of toxic fumes, the weight of the material being handled, the temperature of the material being handled, the danger of working near rotating or press machinery, or environments containing high levels of radiation.Repetitive JobsIn addition to taking over hazardous jobs，robots are well suited to doing extremely repetitive jobs that must be done in manufacturing plants .Many jobs in manufacturing plants require a person to act more like a machine than like a human. The job may be to pick a piece up from here and place it there. The same job is done hundreds of times each day. The job requires little or no judgment and little or no skill .This is not said as a criticism of the person who does the job, but is intended simply to point out that many of these jobs exist in industry and must be done to complete the manufacture of products. A robot can be played at such a work station and can perform the job admirably without complaining or experiencing the fatigue and boredom normally associated with such a job.8Robot SpeedAlthough robots increase productivity in a manufacturing plant, they are not exceptionally fast. At present, robots normally operate at or near the speed of a human operator. Every major move of a robot normally takes approximately one second. For a robot to pick us a piece of steel from a conveyor and load it into a lathe may require ten different moves taking as much as ten seconds. A human operator can do the same job in the same amount of time. The increase in productivity is a result of the consistency of operation. As the human operator repeats the same job over and over during the workday, he or she begins to slow down. The robot continues to operate at its programmed speed and therefore completes more parts during the workday.Custom-built automated machines can be built to do the same jobs that robots do. An automated machine can do the same loading operation in less than half the time required by a robot or a human operator. The problem with designing a special machine is that such a machine can perform only the specific job, or which it was built. If any change is made in the job，the machine must he completely rebuilt, or the machine must be scrapped and a new machine designed and built .A robot, on the other hand, could be reprogrammed and could start doing the new job the same day.Custom-built automated machines still have their place in industry. If a company knows that a job will not change for many years, the faster custom-built machine is still a good choice.Other jobs in factories cannot be done easily with custom-built machinery. For these applications a robot may be a good choice .An example of such an application is spray painting. Spray painting is a hazardous job, because the fumes from many paints are both toxic and explosive. A robot is now doing the job of spraying paint on the enclosures. A robot has been “taught“ to spray all the different sizes of enclosures that the company builds. In addition, the robot can operate in the toxic environment of the spray booth without any concern for the long-term effect the fumes might have on a person working in the booth.Flexible AutomationRobots have another advantage: they can be taught to do different jobs in the manufacturing plant. If a robot was originally purchased to load and unload a punch press and the job is no longer needed due to a change in product design，the robot can be moved to another job in the plant. For example, the robot could be moved to the end of the assembly operation and be used to unload the finished enclosures from a conveyor and load them onto a 9pallet for shipment.Accuracy and RepeatabilityOne very important characteristic of any robot is the accuracy with which it can perform its task. When the robot is programmed to perform a specific task, it is led to specific points and programmed to remember the locations of those points .After programming has been completed, the robot is switched to “run“ and the program is executed. Unfortunately, the robot will not go to the exact location of any programmed point，F(xiàn)or example，the robot may miss the exact point by 0.025 in. If 0.025 in. is the greatest error by which the robot misses any point during the first execution of the program，the robot is said to have an accuracy of 0.025 in. In addition to accuracy, we are also concerned with the robot's repeatability. The repeatability of a robot is a measure of how closely it returns to its programmed points every time the program is executed. Say, for example, that the robot misses a programmed point by 0.025 in. the first time the program is executed and that, fluxing the next execution of the program, the robot misses the point it reached during the previous cycle by 0.010 in. Although the robot is a total of 0.035 in. from the original programmed point，its accuracy is 0 .025 in, and its repeatability is 0 .010 in.The Major Parts of a RobotThe major parts of a robot are the manipulator, the power supply, and the controller. The manipulator is used to pick up material, parts, or special tools used in manufacturing. The power supply supplies the power to move the manipulator. The controller controls the power supply so that the manipulator can be taught to perform its task.Axes of Robot MovementThe various movements that the manipulator of a robot can make are defined by its degrees of freedom or axes. If a robot’s manipulator can rotate, the robot is said to be a single-axis robot .If the manipulator can move up and down as well as rotate, the robot is called a two-axis robot. If in addition to the rotational movement and the up-and-down movement，the manipulator can also extend its arm, or “reach“, the robot is said to be a three axis robot(Fig.24.1).Most industrial robots have all three major axes(rotational, up and down, and reach) as well as some minor axes of movement.10Fig.24.1 Three-axis robot with cylindrical (post-type) manipulator, illustrating two linear axes, and one rotational axis, of movementThe minor axes of a robot are found in the robot's wrist, The wrist of a robot is attached to the end of the robot’s arm. These are three possible movements or axes of a rolx3t wrist: pitch, roll and yaw (Fig.24.2).The pitch movement bends the wrist up and down .The roll movement is the twisting of the wrist. The yaw movement is the side-to-side movement of the wrist. 11Fig.24.2 The three possible movements or axes of a robot wristThe combination of the major axes and the minor axes gives the robot six possible movements ( six axes or six degrees of freedom ).Many industrial robots are equipped with all six axes robots, however, have the three major axes but only one or two of the minor axes. Classification of RobotsThe total area that the end of the robot’s: arm can reach is called the work envelope. T Robots can be classified according to their work envelopes into four types: the cylindrical coordinate robot, the rectangular coordinate robot, the spherical coordinate robot, and the jointed arm coordinate robot. They also can be classified by motion control .There are three major classifications of motion for robots: pick-and-place, point-to-point, and continuous path. These terms describe the movements the manipulator can make within its work envelope,Selected from “Robotics and Automated systems”, Robert L. Hoekstra, CmfgE, South-Western Publishing Co, 1986.12教師評(píng)語教師簽名：