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1、<p><b>  中文2840字</b></p><p><b>  外文資料</b></p><p>  INDYSTIAL ROBOTS</p><p>  There are a variety of definitions of the term robot.Depending on the defi

2、nitino used,the number of robot installatinos wordwide varies widely.Numerous single-purpose machines are used in manufacturing plants that might appear to be robots.These machines are hardwired to perform a single funct

3、ion and cannot 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 </p>&l

4、t;p>  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.</p>&

5、lt;p>  Note that this definition contains the words reprogrammable and multifunctional.It is these two characteristics that separate the true industrial robot form the various single-purpose machines used in modern ma

6、nufacturing firms.The term “reprogrammable” implies two things: The robot operates according to a written program,and this program can be rewriten to accommodate a variety of manufacturning tasks.</p><p>  T

7、he term “multifunctional” means that the robot can, through reprogramming and the use of different end-dffectors, perform a number of different manufacturing tasks.Definitions written around these two critical characteri

8、stics are becoming the accepted definitions among manufacturing professioals.</p><p>  The first articulated arm came about in 1951 and was used by the U.S.Atomic Energy Commission.In 1945,the first programm

9、able robot was designed by George Devol.It was based on two important technologies:</p><p>  (1) Numerical control (NC) technology.</p><p>  (2) Remote manipulation technology.</p><p&

10、gt;  Numerical control technology provided a form 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 mov

11、es, timing signals to initiste action and to stop movement, and logic statements to allow for decision making.</p><p>  Remote manipulator technology allowed a machines to be more than just another NC machin

12、e.It allowed such machines to become robots that can perform a variety of manufacturing tasks in both inaccessible and unsafe environments.By merging these two technologies, Devol developed the first industrial robot, an

13、 unsophisticated programmable materials handling machine.</p><p>  The first commercially produced robot was developed in 1959.In 1962, the first industrial robot to be used on a production line was installe

14、d 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 controlled bya minicomputer.</p><p&g

15、t;  Numerical control and remote and remote manipulator technology prompted the wide-scale development and use of industrial robots.But major technological developments do not take place simply because of such new capabi

16、lities.Something must provide the impetus for taking advantage of these capabilities.In the case of industrial robots, the impetus was economics.</p><p>  The rapid inflation of wages experienced in the 1970

17、s tremendously increased the personnel costs of manufacturing firms.At the same time, foreign competition became a serious problem for U.S.manefacturers.Foreign manufacturers who had undertaken automation on a wide-scale

18、 basis, such as those in Japan, began to gain an increaaingly large share of the U.S.and world market for manufactured goods, particullarly automobiles.</p><p>  Through a variety of automation techniques, i

19、ncluding 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 t

20、o consider any technological developments that could help improve productivity.</p><p>  It become imperative to produce better products at lower costs in order to be competitive with foreign manufacturers.O

21、ther factors such as the need to find better ways of performing dangerous manufacturing tasks contributed to the development of industrial robots.However, the principal rationale has always been, and is still, improved p

22、roductivity.</p><p>  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 robots can be used mor

23、e safely than humans.Even though robots are closely associsted with safety in the workplace, they can, in themselves, be dangerous.</p><p>  Robots and robot cells must be carefully designed and cinfigured s

24、o that they do not endanger human workers and other machines.Robot work envelopes should be accurately calculated and a danger zone surrounding the envelope clearly marked off.Red flooring strips and barriers can be used

25、 to keep human workers out of a robot is work envelope.</p><p>  Even with such precautions it is still a good idea to have an automatic shutdown system in situations where robots are used.Such a system shou

26、ld have the capacity to sense the need for an automatic shutdown of operations.Fault-tolerant computers and redundant systems can be installed to ensure proper shutdown of robotics systems to ensure a safe environment.&l

27、t;/p><p>  The components of a tobot systerm could be discussed either forma physical of view or from a systems point of ciew.Physically, we would divide the system into the robot, power system, and controller(

28、computer).Likewise, the robot itself could be partitioned anthropomorphically into base, shoulder, elbow, wrist, gripper, and tool.Most of these terms require little explanation.</p><p>  Consequently, we wi

29、ll describe the components of a tobot system from the point of view of information transfer.That is, what information or signal enters the component; what logical or arithmetic operation does the component perform; and w

30、hat information or signal does the component produce? It is important to note that the same physical component may perform many different information processing operations (e.g., a central computer performs many differen

31、t calculations on different data ).Likewi</p><p>  Actuator Associated with each joint on the robot is an actuator which causes that joint to move.Typical actuators are electric motors and hydtraulic cylinde

32、rs.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 ofte

33、n built with five or fewer actuators.</p><p>  Sensor To control and actuator, the computer must have information regarding the posetion and possibly the velocity of the actuator.In this contest, the term po

34、sition 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.</p&g

35、t;<p>  Many types of sensors can provide indications of position and velocity.The various types of sensors require different menchanisms for interfacing to the computer.In addition, the industrial use of the mani

36、pulator requires that the interface be protected from the harsh electrical environment of the factroy.Sources of electrical noise such as are welders and large motors can easily make a digital system useless unless care

37、is taken in design and construction of the interface.</p><p>  Computation We could easily have labeled the computation module “ computer , ” as most of the function to be described are typically performed b

38、y digital computer.However, many of the functions may be performed in dedicated custom hardware or networks of the computers.We will, thus, discuss the computational component as if it were a simple computer, recognizing

39、 that the need for real-time control may require special equipment and that some of this equipment may even be analog, although the curr</p><p>  One further note: We will tend to avoid the use of the term m

40、icroprocessor in this book and simply say computer, although many current robot manufacturers use one or more microprocessors in their systerms.</p><p>  The computation component performs the following oper

41、ations:</p><p>  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

42、each actuator.</p><p>  Kinematics Given the current state of the actuators ( position and velocity ), determine the current state of the gripper.Conversely, given a desired state of the hand, determine the

43、desired state for each actuator.</p><p>  Dynamics Given konwledge of the loads on the arm ( inertia, friction, gravity, acceleration ), use this information to adjust the servo operation to achieve better p

44、erformance.</p><p>  Workplace Sensor Analysis Given knowledge of the task to be performed, determine appropriate robot motion commands.This may include analyzing a TV picture of the workplace or measuring a

45、nd compensating for forces applied at the hand.</p><p>  In addition to these easily identified components, there are also supervisory operations such as path planning and operator interaction.</p>&l

46、t;p><b>  工業(yè)機(jī)器人</b></p><p>  有許多關(guān)于機(jī)器人這個(gè)術(shù)語的定義。采用不同的定義,全世界各地機(jī)器人的數(shù)量就會(huì)發(fā)生很大的變化。在制造工廠中使用的許多單用途機(jī)器可能看起來像機(jī)器人。這些機(jī)器是硬連線的,不能通過重新編程的方式去完成不同的工作。這種單用途的機(jī)器不能滿足被人們?nèi)找鎻V泛接受的關(guān)于工業(yè)機(jī)器人的定義。這個(gè)定義是由美國機(jī)器人協(xié)會(huì)提出的:</p>&

47、lt;p>  機(jī)器人是一個(gè)可以改編程序的多功能操作器,被設(shè)計(jì)用來按照預(yù)先編制的 能夠完成多種作業(yè)的運(yùn)動(dòng)程序運(yùn)送材料、零件、工具或者專用設(shè)備。</p><p>  注意在這個(gè)定義中包含有“可以改編程序”和“多功能”這兩個(gè)詞。正是這兩個(gè)詞將真正的機(jī)器人與現(xiàn)代制造工廠中使用的單一用途的機(jī)器區(qū)分開來。“可以改編程序”這個(gè)術(shù)語意味著兩件事:機(jī)器人根據(jù)編寫的程序工作,以及可以通過重新編寫程序來適應(yīng)不同種類的制造工作的重

48、要。</p><p>  “多功能”這個(gè)詞意味著機(jī)器人能通過編程和使用不同的末端執(zhí)行機(jī)構(gòu),來完成不同的制造工作。圍繞著這兩個(gè)關(guān)鍵特征所撰寫的定義正在變成為制造業(yè)的專業(yè)人員所接受的定義。</p><p>  第一個(gè)帶有活動(dòng)關(guān)節(jié)的手臂于1951年被研制出來,由美國原子能委員會(huì)使用。在1954年,第一個(gè)可以編程的機(jī)器人由喬治·狄弗設(shè)計(jì)出來。它基于下面兩項(xiàng)重要技術(shù):</p>

49、<p>  (1)數(shù)字控制(NC)技術(shù)。</p><p> ?。?)遠(yuǎn)程操作技術(shù)。</p><p>  數(shù)字控制技術(shù)提供了一種非常適合于機(jī)器人的機(jī)器控制技術(shù)。它可以通過存儲(chǔ)的程序?qū)\(yùn)動(dòng)進(jìn)行控制。這些程序包含機(jī)器人進(jìn)行順序運(yùn)動(dòng)的數(shù)據(jù),開始運(yùn)動(dòng)和停止運(yùn)動(dòng)的時(shí)間控制信號(hào),以及做出決定所需要的邏輯語句。</p><p>  遠(yuǎn)程操作器技術(shù)使得一臺(tái)機(jī)器的性能超出一

50、臺(tái)數(shù)控機(jī)器。它可以使這種機(jī)器能夠在不容易進(jìn)入和不安全的環(huán)境中完成各種制造任務(wù)。通過融合了上述兩項(xiàng)技術(shù),狄弗研制出第一個(gè)機(jī)器人,它是一個(gè)不復(fù)雜的,可以編程的物料運(yùn)送機(jī)器人。</p><p>  第一臺(tái)商業(yè)化生產(chǎn)的機(jī)器人在1959年研制成功。通用汽車公司在1962年安裝了第一臺(tái)用于生產(chǎn)線上的工業(yè)機(jī)器人,它是尤尼梅森公司生產(chǎn)的。在1973年,辛辛那提·米蘭克朗公司研制出T-3機(jī)器人是第一臺(tái)商業(yè)化生產(chǎn)的采用計(jì)算

51、機(jī)控制的機(jī)器人。</p><p>  數(shù)字控制技術(shù)和遠(yuǎn)程操作技術(shù)推動(dòng)了大范圍的機(jī)器人研制和應(yīng)用。但是主要的技術(shù)進(jìn)步不僅僅是由于這些新的應(yīng)用能力而產(chǎn)生的,而是必須由利用這些能力所得到的效益來提供動(dòng)力。就工業(yè)機(jī)器人而言,這個(gè)動(dòng)力是經(jīng)濟(jì)性。</p><p>  在20世紀(jì)70年代中,工資的快速增長(zhǎng)大大增加了制造業(yè)在企業(yè)中的人工費(fèi)用。與此同時(shí),來自國外的競(jìng)爭(zhēng)成為美國制造業(yè)所面臨的一個(gè)嚴(yán)峻的考驗(yàn)。諸

52、如日本等外國的制造廠家在廣泛地應(yīng)用了自動(dòng)化技術(shù)之后,其工業(yè)產(chǎn)品,特別是汽車,在美國和世界市場(chǎng)中占據(jù)了日益增大的份額。</p><p>  通過采用包括機(jī)器人在內(nèi)的各種自動(dòng)化技術(shù),從70年代開始,日本的制造廠家能夠比沒有采用自動(dòng)化技術(shù)的美國制造廠家生產(chǎn)更好的和更便宜的汽車。隨后,為了生存,美國制造廠家被迫考慮采用任何能夠提高生產(chǎn)率的技術(shù)。</p><p>  為了與國外制造廠家進(jìn)行競(jìng)爭(zhēng),必須

53、以比較低的成本,生產(chǎn)出更好的產(chǎn)品。其他的因素,諸如尋找能夠更好地完成帶有危險(xiǎn)性的制造工作的方式也促進(jìn)了工業(yè)機(jī)器人的發(fā)展。但是,主要的理由一直是,而且現(xiàn)在仍然是提高生產(chǎn)率。</p><p>  機(jī)器人的一個(gè)主要優(yōu)點(diǎn)是它們可以在對(duì)于人類來說是危險(xiǎn)的位置上工作。采用機(jī)器人進(jìn)行焊接和切斷工作是比由人工來完成這些工作更安全的例子。盡管機(jī)器人與工作地點(diǎn)的安全密切相關(guān),它們本身也可能是危險(xiǎn)的。</p><p

54、>  應(yīng)該仔細(xì)地設(shè)計(jì)和配置機(jī)器人和機(jī)器人單元,使它們不會(huì)傷害人類和其他機(jī)器。應(yīng)該精確地計(jì)算出機(jī)器人的工作范圍,并且在這個(gè)范圍的四周清楚地標(biāo)出危險(xiǎn)區(qū)域??梢圆捎玫孛嫔系募t顏色帶子和障礙物以阻止工人進(jìn)入機(jī)器人的工作范圍。</p><p>  即使有了這些預(yù)防措施,在使用機(jī)器人的場(chǎng)地中設(shè)置一個(gè)自動(dòng)停止工作的系統(tǒng)仍然不失為一個(gè)好主意。機(jī)器人的這個(gè)系統(tǒng)應(yīng)該具有能夠檢測(cè)出是否有需要自動(dòng)停止工作的要求的能力。為了保證能有

55、一個(gè)安全的環(huán)境,應(yīng)當(dāng)安裝容錯(cuò)計(jì)算機(jī)和冗余系統(tǒng)來保證在適當(dāng)?shù)臅r(shí)候停止機(jī)器人工作。</p><p>  可以從物質(zhì)的觀點(diǎn)也可以從系統(tǒng)的觀點(diǎn)來討論機(jī)器人系統(tǒng)的組成部分。從物質(zhì)上看,我們可以將系統(tǒng)分成機(jī)器人、電源系統(tǒng)和控制器(計(jì)算機(jī))。機(jī)器人本身可以像人一樣被分為基座、肩、肘、腕、抓握器和工具。這些術(shù)語中的大部分不需要作任何解釋。</p><p>  因此,我們將依照信息轉(zhuǎn)換的觀點(diǎn)來描述機(jī)器人系統(tǒng)

56、的組成部分。也就是,什么信息或者信號(hào)進(jìn)入計(jì)算機(jī)的組成部分,這個(gè)組成部分進(jìn)行何種邏輯或者算術(shù)運(yùn)算,這個(gè)組成部分產(chǎn)生什么信息或者信號(hào)?應(yīng)該認(rèn)識(shí)到,同一個(gè)組成部分可以完成許多不同的信息處理工作(例如,中心計(jì)算機(jī)可以根據(jù)不同的數(shù)據(jù)進(jìn)行許多不同種類的計(jì)算),這一點(diǎn)是很重要的。與之相似,在結(jié)構(gòu)上分開的兩個(gè)組成部分可以進(jìn)行相同的信息操作(例如,肩部和肘部的執(zhí)行機(jī)構(gòu)用非常相似的方式將信息轉(zhuǎn)換成運(yùn)動(dòng))。</p><p>  執(zhí)行機(jī)

57、構(gòu) 執(zhí)行機(jī)構(gòu)與機(jī)器人的每一個(gè)關(guān)節(jié)相連,并且驅(qū)動(dòng)這個(gè)關(guān)節(jié)進(jìn)行運(yùn)動(dòng)。電動(dòng)機(jī)和液壓油缸是典型的執(zhí)行機(jī)構(gòu)。由于對(duì)位置和方向進(jìn)行完全控制需要六個(gè)變量,通常一個(gè)機(jī)器人系統(tǒng)需要六個(gè)執(zhí)行機(jī)構(gòu)。在實(shí)際應(yīng)用中,許多機(jī)器人并不需要具體有這種完全的靈活性,因此,機(jī)器人通常只有五個(gè)或者更少的執(zhí)行機(jī)構(gòu)。</p><p>  傳感器 為了控制執(zhí)行機(jī)構(gòu),計(jì)算機(jī)內(nèi)必須有關(guān)于執(zhí)行機(jī)構(gòu)位置的信息,還可能有執(zhí)行機(jī)構(gòu)速度的信息。這里所說的位置是指執(zhí)行

58、機(jī)構(gòu)相對(duì)任意參考點(diǎn)的位移。例如在旋轉(zhuǎn)機(jī)構(gòu)中,“位置”為角度的位置,并且采用弧度為單位來對(duì)其進(jìn)行度量。</p><p>  許多種類的傳感器能夠表示出位置和速度。各種傳感器需要有不同的機(jī)構(gòu)作為它與計(jì)算機(jī)之間的鏈接裝置。此外,操縱型機(jī)器人在工業(yè)中的應(yīng)用要求對(duì)這種連接裝置加以保護(hù),使其免受工廠中的惡劣電氣環(huán)境的影響。如果在設(shè)計(jì)和制作時(shí)沒有認(rèn)真考慮對(duì)數(shù)學(xué)系統(tǒng)的連接裝置加以保護(hù),諸如電弧焊機(jī)和大電動(dòng)機(jī)所產(chǎn)生的電氣噪聲源可以

59、很容易地使這個(gè)數(shù)字系統(tǒng)失去作用。</p><p>  計(jì)算部分 我們可以容易地將計(jì)算模板稱為計(jì)算機(jī),這是因?yàn)槲覀儗⒁枋龅拇蟛糠止δ芡ǔJ怯蓴?shù)字計(jì)算機(jī)完成的。然而,許多功能也可以由專用的硬件或者計(jì)算機(jī)網(wǎng)絡(luò)來完成。應(yīng)該認(rèn)識(shí)到在要求進(jìn)行實(shí)時(shí)控制時(shí),可能需要專門的設(shè)備,盡管目前的趨勢(shì)是向著全數(shù)字化發(fā)展,這個(gè)設(shè)備的某些部位甚至還可能采用模擬方式。在我們將把計(jì)算部分當(dāng)做一個(gè)簡(jiǎn)單的計(jì)算機(jī)來討論。</p>&l

60、t;p>  進(jìn)一步的說明:盡管許多機(jī)器人制造廠家目前在他們的系統(tǒng)中使用一個(gè)或者幾個(gè)微處理器,在本書中我們避免使用微處理器這個(gè)術(shù)語,簡(jiǎn)單地將其稱之為計(jì)算機(jī)。</p><p>  計(jì)算部分可以完成下述工作:</p><p>  伺服 已知執(zhí)行機(jī)構(gòu)當(dāng)前的位置和/或速度,確定使執(zhí)行機(jī)構(gòu)向著它預(yù)定的位置運(yùn)動(dòng)的驅(qū)動(dòng)信號(hào)。對(duì)于每一個(gè)執(zhí)行機(jī)構(gòu)都需要進(jìn)行這種控制。</p><p&

61、gt;  運(yùn)動(dòng)學(xué) 已知執(zhí)行機(jī)構(gòu)目前的狀態(tài)(位置和速度),確定抓握器目前的狀態(tài)。相反地,已知手的一個(gè)期望狀態(tài),確定每一個(gè)執(zhí)行機(jī)械的期望狀態(tài)。</p><p>  動(dòng)力學(xué) 已知機(jī)器人臂的負(fù)載信息(慣量、摩擦、重力、加速度), 利用這種信息對(duì)伺服機(jī)構(gòu)進(jìn)行控制,以取得更好的工作特性。</p><p>  在工作地點(diǎn)進(jìn)行傳感器信息分析 已知需要完成的任務(wù)的信息,確定適當(dāng)?shù)臋C(jī)器人運(yùn)動(dòng)指令。這可能

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