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c)The text under consideration is about the main criteria to classify robot manipulators. These criteria are robots power source, application area, method of control and their geometry.

d)The first part deals with such a criterion as robots power source. The author says that robots are either electrically, hydraulically, or pneumatically powered.

e)Finally robots kinematic structure is given.

f)The third part of the text describes robots according to their method of control. In this case we can classify robots into servo and non-servo robots. Non-servo robots are open-loop devices whose movement is limited, while servo robots are multifunctional and reprogrammable devices which use closed-loop computer control to determine their motion.

1)_____

2)_____

3)_____

4)_____

5)_____

6)_____

Classification of Robotic Manipulators

Robot manipulators can be classified by several criteria, such as their power source, or way in which the joints are actuated, their geometry, or kinematic structure, their intended application area, or their method of control. Such classification is useful primarily in order to determine which robot is right for a given task. For example, a hydraulic robot would not be suitable for food handling or clean room applications.

Power Source. Typically, robots are either electrically, hydraulically, or pneumatically powered. Hydraulic actuators are unrivaled in their speed of response and torque producing capability. Therefore hydraulic robots are used primarily for lifting heavy loads. The drawbacks of hydraulic robots are that they tend to leak hydraulic fluid, require much more peripheral equipment (such as pumps, which require more maintenance), and they are noisy. Robots driven by DCor AC-servo motors are increasingly popular since they are cheaper, cleaner and quieter. Pneumatic robots are inexpensive and simple but cannot be controlled precisely. As a result, pneumatic robots are limited in their range of applications and popularity.

Application Area. Robots are often classified by application into assembly and non-assembly robots. Assembly robots tend to be small, electrically driven and either revolute or SCARA (Selective Compliant Articulated Robot for Assembly) in design. The main nonassembly application areas to date have been in welding, spray painting, material handling, and machine loading and unloading.

Method of Control. Robots are classified by control method into servo and nonservo robots. The earliest robots were non-servo robots. These robots are essen-

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tially open-loop devices whose movement is limited to predetermined mechanical stops, and they are useful primarily for materials transfer. In fact, according to the definition given previously, fixed stop robots hardly qualify as robots. Servo robots use closed-loop computer control to determine their motion and are thus capable of being truly multifunctional, reprogrammable devices.

Servo controlled robots are further classified according to the method that the controller uses to guide the end-effector. The simplest type of robot in this class is the point-to-point robot. A point-to-point robot can be taught a discrete set of points but there is no control on the path of the end-effector in between taught points. Such robots are usually taught a series of points with a teach pendant. The points are then stored and played back. Point-to-point robots are severely limited in their range of applications. In continuous path robots, on the other hand, the entire path of the end-effector can be controlled. For example, the robot endeffector can be taught to follow a straight line between two points or even to follow a contour such as a welding seam. In addition, the velocity and/or acceleration of the end-effector can often be controlled. These are the most advanced robots and require the most sophisticated computer controllers and software development.

Geometry. Most industrial manipulators at the present time have six or fewer de- grees-of-freedom. These manipulators are usually classified kinematically on the basis of the first three joints of the arm, with the wrist being described separately. The majority of these manipulators fall into one of five geometric types: articulated (RRR), spherical (RRP), SCARA (RRP), cylindrical (RPP), or Cartesian (PPP). Each of these five manipulator arms are serial link robots. A sixth distinct class of manipulators consists of the so-called parallel robot. In a parallel manipulator the links are arranged in a closed rather than open kinematic chain.

8. Read the text about the historical development of Robotics, ask 8–10 questions for the text and make its summary.

Historical Development

The first position controlling apparatus was invented around 1938 for spray painting. However, the first industrial modern robots were the Unimates, made by J. Engelberger in the early 60s. Unimation was the first to market robots. Therefore, Engelberger has been called the father of robotics. In the 80s the robot industry grew very fast primarily because of the huge investments by the automotive industry.

In the research community the first automata were probably Grey Walter’s machina (1940s) and the John’s Hopkins beast. The first programmable robot was designed by George Devol in 1954. Devol funded Unimation. In 1959 the first commercially available robot appeared on the market. Robotic manipulators were used in industries after 1960, and saw sky rocketing growth in the 80s.

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Robots appeared as a result of combination two technologies: teleoperators, and computer numerical control (CNC) of milling machines. Teleoperators were developed during World War II to handle radioactive materials, and CNC was developed to increase the precision required in machining of new technologic parts. Therefore, the first robots were nothing but numerical control of mechanical linkages that were basically designed to transfer material from point A to B.

Today, more complicated applications, such as welding, painting, and assembling, require much more motion capability and sensing. Hence, a robot is a multi-disciplinary engineering device. Mechanical engineering deals with the design of mechanical components, arms, end-effectors, and also is responsible for kinematics, dynamics and control analyses of robots. Electrical engineering works on robot actuators, sensors, power, and control systems. System design engineering deals with perception, sensing, and control methods of robots. Programming, or software engineering, is responsible for logic, intelligence, communication, and networking.

Today we have more than 1000 robotics-related organizations, associations, and clubs; more than 500 robotics-related magazines, journals, and newsletters; more than 100 robotics-related conferences, and competitions each year; and more than 50 robotics-related courses in colleges. Robots find a vast amount industrial applications and are used for various technological operations. Robots enhance labor productivity in industry and deliver relief from tiresome, monotonous, or hazardous works. Moreover, robots perform many operations better than people do, and they provide higher accuracy and repeatability. In many fields, high technological standards are hardly attainable without robots. Apart from industry, robots are used in extreme environments. They can work at low and high temperatures; they don’t even need lights, rest, fresh air, a salary, or promotions. Robots are prospective machines whose application area is widening and their structures getting more complex.

It is claimed that robots appeared to perform in 4A for 4D, or 3D3H environments. 4A performances are automation, augmentation, assistance, and autonomous; and 4D environments are dangerous, dirty, dull, and difficult. 3D3H means dull, dirty, dangerous, hot, heavy, and hazardous. (taken from Theory of Applied Robotics written by Reza N. Jazar)

9. Read the text, give it a title and write the summary of the text.

A program that has not been tested does not work. The ideal of designing and/or verifying a program so that it works the first time is unattainable for all but the most trivial programs. We should strive toward that ideal, but we should not be fooled into thinking that testing is easy.

“How to test?” is a question that cannot be answered in general. “When to test?” however, does have a general answer: as early and as often as possible. Test strategies should be generated as part of the design and implementation ef-

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forts or at least should be developed in parallel with them. As soon as there is a running system, testing should begin. Postponing serious testing until "after the implementation is complete" is a prescription for slipped schedules and/or flawed releases.

Wherever possible, a system should be designed specifically so that it is relatively easy to test. In particular, mechanisms for testing can often be designed right into the system. Sometimes this is not done out of fear of causing expensive run-time testing or for fear that the redundancy necessary for consistency checks will unduly enlarge data structures. Such fear is usually misplaced because most actual testing code and redundancy can, if necessary, be stripped out of the code before the system is shipped. Assertions are sometimes useful here.

More important than specific tests is the idea that the structure of the system should be such that we have a reasonable chance of convincing ourselves and our users/customers that we can eliminate errors by a combination of static checking, static analysis, and testing. Where a strategy for fault tolerance is developed, a testing strategy can usually be designed as a complementary and closely related aspect of the total design.

If testing issues are completely discounted in the design phase, then testing, delivery date, and maintenance problems will result. The class interfaces and the class dependencies are usually a good place to start work on a testing strategy.

Determining how much testing is enough is usually hard. However, too little testing is a more common problem than too much. Exactly how many resources should be allocated to testing compared to design and implementation naturally depends on the nature of the system and the methods used to construct it. However, as a rule of thumb, I can suggest that more resources in time, effort, and talent should be spent testing a system than on constructing the initial implementation. Testing should focus on problems that would have disastrous consequences and on problems that would occur frequently. (Taken from The C++ Programming Language, Third Edition by Bjarne Stroustrup)

9. Read the extract written by Mike Clark, an independent consultant/programmer. What does he write about? What is his advice for future programmers? Do you agree or disagree? Why?

Curiosity Is a Strength

My parents will tell you I was an inquisitive kid. I asked lots of questions, read everything I could get my hands on, and learned how things worked by taking them apart. As it turns out, this wasn’t just a phase – I never outgrew having an insatiable curiosity. It’s easy to overlook, but I believe curiosity can be a strength. Sometimes it just takes a little practice to develop.

Looking back, I can identify several career-changing events that happened mostly because I followed a curiosity. I offer the following examples in hopes they encourage you to listen when curiosity calls: I never figured I’d become a

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programmer. I’d always been fascinated with airplanes and spaceships, so enrolling in Embry-Riddle Aeronautical University’s aerospace engineering program seemed like the logical choice. After a year or so grinding away, however, I discovered that the folks over in the computer science department were having a lot more fun. As part of a new degree program, they were applying computer science toward aviation-related problems. I had become curious about computers in high school but never really considered programming as a career. So, I started hanging out with the computer geeks to see what they were up to. Before long, I had switched degree programs. That single change ended up being one of my best decisions. The courses were still challenging, but I loved every minute. My initial curiosity in programming quickly became a passion that led me to apply for an internship at NASA and jump-started my software career. And to this day I never underestimate the potential reward of finding out what fellow geeks are working on for fun.GO INDEPENDENT 209

Whenever I get comfortable, I know it’s time to try something new. After many years writing embedded software in the aerospace industry, I was comfortable (which for me is also associated with boredom) with C and C++. About this time, web programming piqued my curiosity, mostly because it was radically different from embedded systems programming. Unfortunately, the project at my day job didn’t have web access (it was one of those super-secret projects), so instead I spent my nights and weekends learning how to write software for the Web. This hacking on the side eventually turned into an opportunity to work on a new project using Java. I ended up building web-based Java applications for many more projects...and employers. My curiosity about web development was the catalyst for diversifying my skills, which ended up being a good career move.

I learned Ruby and Rails on a whim. Ruby was a fun language that made me think about programming differently. Rails did the same for web applications. I didn’t have any clients at the time who were paying for Ruby or Rails work, but that didn’t really matter. I was curious, and I just couldn’t help myself. I took a few less billable hours and spent that time digging into Ruby and Rails. Little did I know that in early 2005 I’d get an opportunity to build one of the first commercial Rails applications and get invited by Dave Thomas to help out on his Rails book. My curiosity about yet another new technology started another successful arc in my career.

I’m curious about more than just technology; business aspects are equally interesting to me. That led me to venture out on my own as an independent consultant and start a training company (The Pragmatic Studio). My curiosity about running a small business gave me the opportunity to learn a bunch of new skills: sales, marketing, customer support, and so on. Seeing the big picture has helped me become a better programmer. So, what are you really curious about? Try following your interests for a little while and see what happens. You might be sur-

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prised where you end up! (taken from Chad Fowler’s book The passionate programmer)

Unit VII. Doing grammar and vocabulary exercises

1. Fill in the gaps in the following sentences with the correct Present Simple or Present Continuous form of the verbs in brackets. Put the adverbs in the correct position.

1. I ……………………. (not/like) getting up in the morning.

2. My brother and I ……………………. (have) to get up quite early to get to school on time.

3.Our father ……………………. (sometimes/drive) us, but on other days we

……………………. (get) the school bus.

4.We almost ……………………. (never/get) to the bus stop on time and the bus

……………… (always/wait) when we ………………. (turn) the corner.

5.The bus driver ………………… (tell) us to hurry up and we ……………….

(jump) on the bus.

6. We ……………… (not/go) to school next Monday because it's a holiday.

7.Instead all the people from my class …………………… (meet) in the mountains for a picnic.

8.I ……………………. (make) a chocolate cake, my friend Lisa………… (bring) a salad and the others ……………… (bring) meat, bread and soft prinks.

9.Lisa ……………………. (ring) me up every evening and asks, 'What

………………. (have) to do for homework?'

11. She ……………………. (always/talk) in class which …………………….

(drive) all the teachers crazy.

12. When Lisa ……………………. (ring) me up, she ……………………

(always/say), "What …………... you ……… …….. ?' (do)

13. And I …………………. (answer) ' I ………………. (talk) to you, silly!'

2. Fill in the gaps in with the correct form of the verbs in brackets.

A:Hello, Mark. You 1) _____ (take) a long time to answer the door.

B:Sorry. I 2) _____ (not/hear) the bell. Come in, Tony.

A:What 3) _____ (you/plan) to do today?

B:Well, I 4) _____ (think) of going for a picnic in the country, but the weather is awful so I 5) _____ (change) my mind.

A:Oh dear. Well, yesterday Mary 6) _____ (tell) me that she 7) _____ (buy) two tickets to see the Rocking Stars, but she couldn’t go to the concert. So I 8) _____

(buy) the tickets from her, because I 9) _____ (think) you’d like to go.

B:Tony, that’s brilliant! I 10) _____ (mean) to buy tickets for that convert, but they 11) _____ (sell out) by the time I 12) _____ (go) to the booking office.

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A: Well, it’s lucky I 13) _____ (see) Mary, then, isn’t it?

3.Fill in the gaps in with the correct form of the verbs in brackets.

1.A: Look at Steve! He is soaking wet. B: I know. He _____ (wash) the car.

2.A: Why _____ (you/make) so much food?

B: Well, I _____ (expect) guests, but they phoned to say they couldn’t come.

3.A: Julia performed well at the concert.

B: Yes. She _____ (practise) for months beforehand.

4.A: _____ (you/ever/go) to Spain?

B: Yes. I _____ (go) last year. 5. A: I like your new coat.

B: Thank you. I _____ (wear) my old coat for years, so I decided to buy a new one.

6. A: Do you know this town well?

B: Of course. I _____ (live) here for six years.

4.Circle the one alternative in the following sentences which is not possible.

(1)Would you like some/a little/a few more chicken?

(2)Can I have another piece/lump/bit of that delicious chocolate?

(3)I had some/a bit of/a good news the other day.

(4)I tried on a/some/a pair of jeans, but they didn't suit me.

(5)I don't usually have much/many/a great deal of spare time during the week.

(6)She gave me some/a piece of/many good advice about the exam.

(7)Many/Few/Much local people came to the meeting.

(8)Why not come and stay with us for a couple of/a pair of/a few days?

(9)Would you like another/some/more toast?

(10)The/Some/A police a/rived straight away.

(11)We usually have a lot of/a/some very nice weather at this time of

year.

(12)How many lumps/teaspoons/slices of sugar do you usually have in your coffee?

(13)Could you give me another piece/sheet/slice of paper, please?

(14)You haven't brought much/many/a lot of luggage with you.

(15)I would like some/a bit of/a few information about your courses.

(16)I put some/any/a bar of chocolate somewhere, but where is it?

(17)I’m afraid we haven’t got any/many/much time.

5.Match a sentence in Column A with a sentence in Column B. Write the appropriate letter in the gaps.

Column A

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1.You must have had a terrible fright. ……..

2.I might be able to come. ……..

3.That can’t be Mary. ……..

4.You should take a coat. …….

5.He can’t have forgotten again. ……..

6.That must be Michael. ……..

7.You should have told me. ………

8.She might not know. ……..

9.You can’t have spent it all. ……..

10.They might have seen it. ……..

Column B

a)He always gets home from work at about this time.

b)I only gave it to you yesterday.

c)It’s been on for a couple of weeks.

d)I reminded him about fifty times.

e)I would have got you a present.

f)It’s going to get cold later.

g)You’re still trembling.

h)I certainly haven’t told her.

i)She is supposed to be at school.

j)I’ll have to ask my parents though.

6.Write responses for the comments using a modal verb from the box and a suitable verb. More than one answer may be possible.

e.g. a) There’s someone at the door with a set of ladders.

b)That will be the window cleaner.

1.a) I can’t find my wallet.

b)___________________

2.a) I bought my Mum some perfume, but she didn’t like it.

b)_______________________________________

3.a) I thought she was Spanish, not Italian.

b)_______________________________

4.a) I failed my exam.

b)___________________

5.a) She looked upset and her eyes were very red.

b)_________________________________

6.a) I don’t know what had happened, but he had a black eye and bruises all over his face.

b)__________________________________________

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7. Read the following text and then fill in the gaps with an appropriate word. You have been given the first three letters of each

before coming up with a brilliant invention almost by accident.

8. Put the words in brackets in the right form, infinitive (with or without to) or –ing form. Translate the sentences into Russian.

1.Had an in-depth talk about O levels with my father, he advised me ____ (do) the subjects that I am good at.

2.I wouldn’t mind ____(be) a sponge-diver, but I don’t think there is much call for them in England.

3.I explained that I had caught my overcoat sleeve on the candle whilst ___(do) my homework.

4.Then she pounced and accused the shop assistant of ____(give) her underweight bacon.

5.My grandma made us ___(get up) early and ____(go) to church with her. My father was made ____(comb) his hair and ___(wear) one of his dead father’s ties.

6.My father kept ____(stand up) when we were supposed ____(sit down)and vice versa.

7.I didn’t go to school today, I rang the school secretary and told that my father is mentally ill and needs ____(look after).

8.She demanded _____(know) what Doreen was doing in the house.

9.She wants me ____(go round) her house tomorrow morning. She wanted

___(see) the red socks but I told her they were in the wash.

10.My grandma is coming round tonight, so all traces of them (Doreen Slater and Maxwell) have got ____(be wiped out).

9. Complete the second sentence so that it has a similar meaning to the first sentence. Use the world in bold and other words to complete each sentence.

EXAMPLE: ‘I’m sorry I got home so late,’ said Mary. apologized

Mary apologized for getting home so late.

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1.‘I won’t tell anyone about it,’ said Kate. promised

Mary’s friend Kate …………………………… anyone about it.

2.‘Mary, you should try being honest with your parents,’ said the doctor. advised

The doctor …………………………………… honest with her parents.

3.‘Don’t go out with that boy again!’ said Mary’s father.

warned

Mary’s father ………………………………… go out with Steve again.

4.‘You’ve been meeting your boyfriend after school, haven’t you?’ said Mum. accused

Mary’s mother ……………………………….. her boyfriend after school.

5.‘Lend me your gameboy, or I’ll tell Mum and Dad,’ said Mary’s brother. threatened

Mary’s brother ……………………………….. her parents unless she lent him her gameboy.

6.‘I haven’t seen Steve since Saturday night,’ said Mary.

denied

Mary ………………………………………….. Steve since Saturday night.

7.‘But I tried to phone him yesterday,’ said Mary. admitted

Mary ………………………………….. him the day before.

8.‘Perhaps I could meet your parents,’ said Steve. suggested

Steve ………………………………… Mary’s parents.

9.‘No, I will not speak to him,’ said Mary’s mother. refused

Mary’s mother …………………………………… Steve.

10.‘Try being a bit more understanding, Mrs Wright,’ said the doctor. encouraged

The doctor ………………………………………… a bit more understanding.

11.‘ I’ve made up my mind. I’m going to ask Steve to lunch on Sunday,’ said Mary’s mother.

decided

Mary’s mother ………………………………….. Steve to lunch on Sunday.

12.‘Would you like to have lunch with us on Sunday, Steve?’ said Mary’s moth-

er.

invited

Mary’s mother …………………………………. lunch with then on Sunday. 13. ‘I think you’re right. Mary is too young to stay out so late,’ said Steve. agreed

Steve ………………………………………….. too young to stay out so late.

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