第一篇：學術(shù)英語PPT演講稿-motor電機介紹

學術(shù)英語國際會議發(fā)言稿——

The Heart of Robot——Motors

學生姓名：劉凈川 學 號：S312070113 學 院：機電工程學院 專 業(yè)：機械設(shè)計及理論

2012.11.20

The Heart of Robot——Motors

Thank you very much, Miss.Zhao, for your kind introduction.Ladies and gentlemen, Good afternoon!I am honored to have been invited to speak at this conference.Today, my topic is about The heart of robot—Motor.As we know, almost all of the robots use electric motor to provide motive power, since its small size and high accuracy.I want to share my interesting research result on motors with you.Overview

The content of this presentation is divided into 4 parts: In session one, I will talk about how to choose a motor for a robot;In session two and three, I will introduce two kinds of motors which are most widely used on robot technology;and finally, I will make a conclusion.1.Choosing a Motor

Electric motors, both ac motors and dc motors, come in many shapes and sizes.Some are standardized electric motors for general-purpose applications.Other electric motors are intended for specific tasks.In any case, electric motors should be selected to satisfy the dynamic requirements of the machines on which they are applied without exceeding rated electric motor temperature.Thus, the first and most important step in electric motor selection is determining load characteristics--torque and speed versus time.Electric motor selection is also based on mission goals, power available, and cost.Above all, the type of motor chosen for an application depends on the characteristics needed in that application.These characteristics include:

How fast you want the object to move，The weight, size of the object to be moved，The cost and size of the motor，The accuracy of position or speed control needed.2.DC Motors

Now, let`s come to the first part—DC motor 2.1 The working principle of brushless DC motor

D.C.machines are characterized by their versatility.By means of various combinations of shunt-, series-, and separately excited field windings they can be designed to display a wide variety of volt-ampere or speed-torque characteristics for both dynamic and steady state operation.Because of the ease with which they can be controlled, systems of D.C.machines are often used in applications requiring a wide range of motor speeds or precise control of motor output.The essential features of a D.C.machine are shown schematically.The stator has salient poles and is excited by one or more field coils.The air-gap flux distribution created by the field winding is symmetrical about the centerline of the field poles.This is called the field axis or direct axis.As we know, the A.C.voltage generated in each rotating armature coil is converted to D.C.in the external armature terminals by means of a rotating commutator and stationary brushes to which the armature leads are connected.The commutator-brush combination forms a mechanical rectifier, resulting in a D.C.armature voltage as well as an armature m.m.f.Wave then is 90 electrical degrees from the axis of the field poles, i.e.in the quadrature axis.In the schematic representation the brushes are shown in quadrature axis because this is the position of the coils to which they are connected.The armature m.m.f.Wave then is along the brush axis as shown.(The geometrical position of the brushes in an actual machine is approximately 90 electrical degrees from their position in the schematic diagram because of the shape of the end connections to the commutator.)2.2 The advantages of brushless DC motor

DC motor have the performance with fast response , a large starting torque, it can provide rated torque from zero speed to rated speed.But advantages of the DC motor is what its shortcomings, because the DC motor produce constant rated load torque , then the armature magnetic field and rotor magnetic field must be constant maintenance of 90 °, which would produce sparks, toner form carbon brush and commutator in the motor rotation ,it will not only make group damaged, but also the using is limited.AC motor have no carbon brushes and commutator, it is

maintenance-free, strong, applied widely, but AC motor need to be achieved with sophisticated control technology if the characteristics of the AC motor is equal to the DC motor performance.Today the rapid development of power semiconductor and more speed of components' switching frequency enhance the performance of the drive motor.Microprocessor speed is also faster and faster, enabling the AC motor control placed in a rotating two-axis orthogonal coordinate system.Proper control of AC motor in the two-axis current components make it achieve similar to the control of DC motor and have comparable performance with the DC motor.In addition, there are a lot of microprocessor controlling the motor's necessary functions made in the chip, and its volume is smaller and smaller, such as digital converter、pulse width modulation and so on.Brushless DC motor control AC motor commutation electronic way , it can get the characteristics similar to the DC motor and it have not a lack of DC motor's institutional.2.3 Brushless DC motor's applications

The research of Variable Frequency Induction Motor in three decades , the final analysis, is looking for induction motors torque control method, rare earth permanent Magnetic brushless DC motor because of the characteristics that wide speed range, small size, high efficiency and of small steady-state speed error has advantages in areas of changing speed apparently.Brushless DC motor have the characteristics of DC brush motor characteristics, but also it is frequency devices, they are called the DC conversion, international general terms for the BLDC.Brushless DC motor because of operating efficiency, low torque, speed control of precision is better than any inverter technology , so it's worth to concern by the industry.This product has produced more than 55kW, can be designed to 400kW, can solve the saving industry and the demand for high-performance driving.3.Stepper Motors

A stepper motor is a brushless, synchronous electric motor that converts digital

pulses into mechanical shaft rotation.Every revolution of the stepper motor is divided into a discrete number of steps, in many cases 200 steps, and the motor must be sent a separate pulse for each step.The stepper motor can only take one step at a time and each step is the same size.Since each pulse causes the motor to rotate a precise angle, typically 1.8°, the motor's position can be controlled without any feedback mechanism.As the digital pulses increase in frequency, the step movement changes into continuous rotation, with the speed of rotation directly proportional to the frequency of the pulses.Step motors are used every day in both industrial and commercial applications because of their low cost, high reliability, high torque at low speeds and a simple, rugged construction that operates in almost any environment.3.1 Types of Step Motors

There are three basic types of step motors: variable reluctance, permanent magnet, and hybrid.This discussion will concentrate on the hybrid motor, since these step motors combine the best characteristics of the variable reluctance and permanent magnet motors.They are constructed with multi-toothed stator poles and a permanent magnet rotor(See figure A).Standard hybrid motors(such as the models offered by OmegamationTM)have 200 rotor teeth and rotate at 1.8o step angles.Because they exhibit high static and dynamic torque and run at very high step rates, hybrid step motors are used in a wide variety of commercial applications including computer disk drives, printers/plotters, and CD players.Some industrial and scientific applications of stepper motors include robotics, machine tools, pick and place machines, automated wire cutting and wire bonding machines, and even precise fluid control devices.3.2 Step Modes

Stepper motor “step modes” include Full, Half and Microstep.The type of step mode output of any stepper motor is dependent on the design of the driver.Omegamation? offers stepper motor drives with switch selectable full and half step modes, as well as microstepping drives with either switch-selectable or software-selectable resolutions.3.2.1 FULL STEP

Standard hybrid stepping motors have 200 rotor teeth, or 200 full steps per revolution of the motor shaft.Dividing the 200 steps into the 360o of rotation equals a 1.8o full step angle.Normally, full step mode is achieved by energizing both windings while reversing the current alternately.Essentially one digital pulse from the driver is equivalent to one step.3.2.2 HALF STEP

Half step simply means that the step motor is rotating at 400 steps per revolution.In this mode, one winding is energized and then two windings are energized alternately, causing the rotor to rotate at half the distance, or 0.9o.Although it provides approximately 30% less torque, half-step mode produces a smoother motion than full-step mode.3.2.3 MICROSTEP

Microstepping is a relatively new stepper motor technology that controls the current in the motor winding to a degree that further subdivides the number of positions between poles.Omegamation microstepping drives are capable of dividing a full step(1.8o)into 256 microsteps, resulting in 51,200 steps per revolution(.007o/step).Microstepping is typically used in applications that require accurate positioning and smoother motion over a wide range of speeds.Like the half-step mode, microstepping provides approximately 30% less torque than full-step mode.3.3 Accuracy

The accuracy for can-stack style steppers is 6-7% per step, non-cumulative.A 7.5° stepper will be within 0.5° of theoretical position for every step, regardless of how many steps are taken.The incremental errors are non-cumulative because the mechanical design of the motor dictates a 360° movement for each full revolution.The physical position of the pole plates and magnetic pattern of the rotor result in a repeatable pattern through every 360° rotation(under no load conditions).3.4 Resonance

Stepper motors have a natural resonant frequency as a result of the motor being a spring-mass system.When the step rate equals the motor’s natural frequency, there may be an audible change in noise made by the motor, as well as an increase in vibration.The resonant point will vary with the application and load, but typically occurs somewhere between 70 and 120 steps per second.In severe cases the motor may lose steps at the resonant frequency.Changing the step rate is the simplest means of avoiding many problems related to resonance in a system.Also, half stepping or micro stepping usually reduces resonance problems.When accelerating to speed, the resonance zone should be passed through as quickly as possible.3.5 Stepper Motor Advantages and Disadvantages 3.5.1 ADVANTAGES

1.The rotation angle of the motor is proportional to the input pulse.2.The motor has full torque at standstill(if the windings are energized).3.Precise positioning and repeatability of movement since good stepper motors have an accuracy of 3 to 5% of a step and this error is non-cumulative from one step to the next.4.Excellent response to starting/stopping/reversing.5.Very reliable since there are no contact brushes in the motor.Therefore the life of the step motor is simply dependant on the life of the bearing.6.The stepper motors response to digital input pulses provides open-loop control, making the motor simpler and less costly to control.7.It is possible to achieve very low speed synchronous rotation with a load that is directly coupled to the shaft.8.A wide range of rotational speeds can be realized as the speed is proportional to the frequency of the input pulses.3.5.2 DISADVANTAGES There are two main disadvantages of stepper motors: 1.Resonance can occur if not properly controlled.This can be seen as a sudden loss or drop in torque at certain speeds which can result in missed steps or loss of synchronism.It occurs when the input step pulse rate coincides with the natural oscillation frequency of the rotor.Resonance can be minimised by using half stepping or micro stepping.2.Not easy to operate at extremely high speeds 3.6 Applications

Stepper motors can be a good choice whenever controlled movement is required.They can be used to advantage in applications where you need to control rotation angle, speed, position and synchronism.These include

printers

plotters

medical equipment

fax machines

automotive and scientific equipment etc.4.Conclusion

A world without electric motors is difficult to imagine.From the tiniest motor found in a quartz watch to a million-plus horsepower motor powering a ship, motors are used in many diverse applications.And since motors have features as follow:

Energy scales span 38 orders of magnitude

Currents in a magnetic field feel a force

Currents produce magnetic fields

Permanent magnets can spontaneously aligned moments Motors are widely used in robot technology.

第二篇：英語學術(shù)演講稿

Good morning everyone.Welcome to my presentation.My name is …My major is mechanical engineering.The research direction of my team is the robot, so I’ll talk something about applications of the teleoperator robot in our life with two examples.The main contents of my speech are the medical robot and the cooking robot.First of all, we should know what teleoperator robot is.Teleoperator robots are mainly used for various operations of non-industrial production, for example, the medical robot, the cooking robot and the cleaning robot.Let’s first see the medical robot.The main characteristics of the medical robot is remote control.The remote control lets people stride across the space-time barrier.It means that the doctor and the patient can be in different places, as is shown in the pictures.The patient is in Strasbourg while the surgeon is in New York.The display screen provides surgery scene to the surgeon.By operating the main operation terminal and inputting commands, doctors can control the robot to have surgery.Robots can also serve our daily life.Most of us may already know that the robot cooks in the university cafeteria of Beijing Jiaotong University.We all think that it’s very interesting.These pictures show us the process of the robot cooking.First, the chef puts raw materials into the robot, then choses the dish to cook in the display screen.Next, the robot starts to cook.In the cooking process, the chef follows the robot’s voice prompts to add spices.Just three minutes later, the robot pours the cooked dish into the prepared basin.The robot cooking not only takes less time but also uses less gas.It can save fifty percent of gas.As the above examples allude, teleoperator robots provide service for mankind and make our life more convenient.Meanwhile they save us a lot of time and sources of energy.I believe in the future teleoperator robots will be more widely used and provide better service to our life.That’s all.Thank you.

第三篇：英語學術(shù)演講稿

Good morning everyone.Welcome to my presentation.My name is …My major is mechanical engineering.The research direction of my team is the robot, so I’ll talk something about applications of the teleoperator robot in our life with two examples.The main contents of my speech are the medical robot and the cooking robot.First of all, we should know what teleoperator robot is.Teleoperator

robots are mainly used for various operations of non-industrial production, for example, the medical robot, the cooking robot and the cleaning robot.Let’s first see the medical robot.The main characteristics ofthe medical robot is remote control.The remote control lets people stride across the space-time barrier.It means that the doctor and the patient can be in different places, as is shown in the pictures.The patient is in Strasbourg while the surgeon is in New York.The display screen

provides surgery scene to the surgeon.By operating the main operation terminal and inputting commands, doctors can control the robot to have surgery.Robots can also serve our daily life.Most of us may already know that the robot cooks in the university cafeteria of Beijing Jiaotong University.We all think that it’s very interesting.These pictures show us the process of the robot cooking.First, the chef puts raw materials into the robot, then choses the dish to cook in the display screen.Next, the robot starts to

cook.In the cooking process, the chef follows the robot’s voice prompts to add spices.Just three minutes later, the robot pours the cooked dish into the prepared basin.The robot cooking not only takes less time but also uses less gas.It can save fifty percent of gas.As the above examples allude, teleoperator robots provide service for mankind and make our life more convenient.Meanwhile they save us a lot of time and sources of energy.I believe in the future teleoperator robots will be more widely used and provide better service to our life.That’s all.Thank you.

第四篇：英語PPT演講稿

吉他唱歌Then,I am going to share the experience of learning guitar and singing songs.To be honest ,I am not good at either of them, I just like them.Singing can be used to relieve my fatigues and can help me improve my accent.Practicing guitar making me happy when I am sad.My hobbies refer to Music, It said that singing along with music or dancing to rhythm can make people clever.I am always singing at home to share each other’s joys and sorrow in our life and to learn many songs.潑水節(jié)It goes without saying that there are many different kinds of activities

and they can not only broaden our minds but also add more fun to our life.For example , Thailand water splashing festival ,It represents

Thailand

Thai

New

Year, The Water-Splashing Festival is in mid-April and lasts three to five days.Water is the most precious thing to the Tai people,they believe the holy water make you get rid of bad luck,the Tai people's wish for your good fortune and happiness sincerely.印尼美食節(jié)In the Indonesian food festival , We satisfy our taste buds,also, we feasted our eyes on the he traditional dances, songs and music.風雅中華And the “feng ya zhong hua” is China traditional cultural Quiz.we had a chance that enabled our to presen our knowledge and practice our cooperative learning skills.五緣水鄉(xiāng) It is a Wetland Park.where we can see many black swans.It is surrounded by verdant trees on

in

its

the

lakeside

and

intoxicates tens ofthousands of people arms with their wonderful charm and its radiant and enchanting scenery in lake water.you can learn much during your travel about the geography, biology, and history of the places you visit.小結(jié)No matter how well educated you are, there is always a lot for you to learn through travelling.The knowledge acquired from travel, as you will have found in your life, is no less valuable than that from any influential reference book.

第五篇：PPT英語演講稿

Why you will fail [fel] to have a great career [k?'r??(r)]你為什么不會成就偉業(yè) 中英對照演講稿：

I want to discuss with you this morning why you're going to fail to have a great career.(Laughter)

今天上午我想和你們討論一下，你為什么不會成就偉業(yè)。（笑聲）

I know some of you have already decided you want a good career.You're going to fail(Laughter).Those trying to have good careers are going to fail, because, really, good jobs are now disappearing.There are great jobs and great careers, and then there are the high-workload, high-stress, bloodsucking['bl?ds?k??], soul-destroying [d??str??] kinds of jobs, and almost nothing in between.我知道你們有些人已經(jīng)決定了，你們想要一個成功的事業(yè)。你們也會失敗的－（笑聲）－。（笑聲）想事業(yè)有成的人會失敗，因為，真的，現(xiàn)在好工作都在消失。有好工作，和好事業(yè)，也有工作量大，壓力大，吸食血液，侵蝕靈魂的那種工作，而且?guī)缀鯖]有工作能好點的。So the people looking for good jobs are going to fail.I'm going to talk about those looking for great jobs, great careers, and why you're going to, why you're going to fail.First reason is that no matter how many times people tell you, “If you want a great career, you have to pursue [p?'sju:] your passion [?p???n], you have to pursue your dreams, you have to pursue, the greatest fascination [?f?s??ne??n] in your life,” you hear it again and again and then you decide not to do it.所以想找好工作的人會失敗。我談?wù)勀切ふ覀I(yè)的人，你們?yōu)槭裁匆獙ふ?，為什么會失敗。第一個原因是不管多少次別人告訴你，“如果你想成就偉業(yè)，你就必須追隨你的熱忱，你必須追隨你的夢想，你必須追隨，你人生中最大的吸引，“ 你聽過這句話一遍又一遍，然后你決定，不去這樣做。I'm not quite sure why you decide not to do it.You're too lazy to do it.It's too hard.You're afraid if you look for your passion and don't find it, you'll feel like you're an idiot [??di?t], so then you make excuses [?k?skjuz] about why you're not going to look for your passion.And they are excuses, boys and girls.We're going to go through a whole long list, your creativity, and thinking of excuses not to do what you really need to do if you want to have a great career.我不太確定你為什么決定不去做。你太懶了。這事太難。你害怕如果你去尋找夢想然后找不到，你會覺得你像個白癡，所以你給自己找借口，為什么你不去追尋你的夢想。這些都是借口，女士們先生們。我們要列一個長單子，你的創(chuàng)造力，想想你不去做成就偉業(yè)該做的事情的借口。

So, for example, one of your great excuses is, “Well, great careers are really and truly, for most people, just a matter of luck, so I'm going to stand around, I'm going to try to be lucky, and if I'm lucky, I'll have a great career.If not, I'll have a good career.” But a good

career is an impossibility, so that's not going to work.所以，舉例來說，你眾多借口之一是，“嗯，偉業(yè)實際上對于大多數(shù)人來說，只是運氣問題，所以我就在這待著，我就試試做那個幸運的人，然后如果我真幸運的話，我就能成就偉業(yè)。如果不能，我就找個還不錯的事業(yè)?！保菦]有還不錯的事業(yè)，所以這個行不通。

Then, your other excuse is, “Yes, there are special people who pursue their passions, but they are talent.I'm not a talent.When I was five, I thought I was a talent, but my

teachers have beaten that idea out of my head long since.”(Laughter)Or“ You see, if this was 1950, being completely competent, that would have given you a great career.But guess what? This is almost 2013.然后，你還有其他借口：“是的，有那些與眾不同的人，追尋自己的夢想，但是他們是天才。我不是天才。我五歲的時候以為自己是天才，但是我的教授們早就把這個念頭，打消了。或者“ 現(xiàn)在你看，如果這是在1950年，完全有能力，就能讓你成就偉業(yè)。但是你知道么？現(xiàn)在幾乎是2013年了。

I have an interest!I have an interest!You tell me.I say, ”That's wonderful!And what, what are you trying to tell me? It is not passion.Passion is your greatest love.Passion is the thing that will help you create the highest expression of your talent.Passion, interest--it's not the same thing.Are you really going to go to your partner and say, “Marry me!You're interesting.” And if that, you will die alone.(Laughter)

我有個興趣！我有個興趣！你告訴我。“我說，”太好了！“ 你想告訴我什么呢？那不是熱枕。熱忱是你最高程度的熱愛。熱忱是能幫助你最好地成就自己才華，的事情。熱忱，興趣－不是一回事。你真的會去找你的甜心然后說，“嫁給我吧！你很有意思?！埃ㄐβ暎┎粫l(fā)生的。不會發(fā)生，然后你會孤獨終老。（笑聲）What you want is passion.It is beyond interest.You need 20 interests, and then one of them, one of them might be passion.你想要的是熱忱。它超越興趣。你需要20個興趣，然后它們其中一個是你的熱忱。But then, there are some of you, in spite of all these excuses, you will find, you will find your passion, and you'll still fail.但是，你們當中有些人，拋開這些借口，你們會找到，你們會找到自己的熱忱，然后你們還是失敗了。

You're going to fail, because, because you're not going to do it, because you will have invented a new excuse, any excuse to fail to take action, and this excuse I've heard so many times.“Yes, I would pursue a great career, but I value human relationships more than accomplishment.I want to be a great friend.I want to be a great spouse [spa?s].I want to be a great parent, and I will not sacrifice ['s?kr?fa?s] them on the altar ['?:lt?(r)] of great accomplishment.”

你會失敗，因為，因為你不會著手去做，因為你會想出新的借口，任何讓你只說不做的借口，而且這個借口，我已經(jīng)聽過很多次了?！笆堑?，我會追求一番偉業(yè)，但是相比成就，我更看重人與人之間的關(guān)系。我想做一個好朋友。我想做一個好伴侶。我想做一個好父母，而且我不會為了，偉大的成就而犧牲這些?！?/p>

You know what will happen someday? One day you will have a child ,And the kid [k?d] will come to you someday and say, “I know what I want to be.I know what I'm going to do with my life.” You are so happy.It's the conversation a parent wants to hear.And you know you're going to like what comes next.Says your kid, “I have decided I want to be a magician [m??d????n].I want to perform magic tricks on the stage.”(Laughter)

你知道有一天會發(fā)生什么？ 你的孩子有一天會跟你說，“我知道我想做什么。我知道我想怎么度過一生?！?，你特別高興。這種對話父母最愛聽了，而且你知道你會愛聽你孩子接下來的話。你孩子說，“我決定了，我想做個魔術(shù)師。我想在舞臺上表演魔術(shù)?！保ㄐβ暎?/p>

And what do you say? “Umm...that's risky, kid.Might fail.Can't make a lot of money at that.You know , you should think about that again , why not — ”

然后你說什么？ 你說，你說，“嗯...那樣比較不保險，孩子。有可能會失敗，孩子。掙不了大錢，孩子。你知道的，我不知道，孩子，你應(yīng)該再想想，孩子，為什么不－“

And the kid interrupts you, and says, “But it is my dream.It is my dream to do this.” And what are you going to say? Like this “Look kid.I had a dream once, too, but--but.” So how are you going to finish the sentence with your “but”? “...But I was afraid to pursue it.” Or, are you going to tell him this? “I had a dream once, kid.But then you were born.”(Laughter)

然后你孩子打斷你，說，”但是那是我的夢想。我夢想就是成為魔術(shù)師。“ 然后你要說什么？ 像這樣”你看，孩子，我過去也有過夢想。但是－但是?！?所以你想怎么用”但是“結(jié)束你的句子？ ”...但是我沒敢去追隨?！?還是，你想告訴他這個？ ”我過去有夢想，孩子。但是之后你出生了。“（笑聲）

Do you, do you really want to use your family, do you really ever want to look at your spouse and your kid and see your jailers [?d?e?l?(r)]? There was something you could

have said to your kid when he or she said, “I have a dream.” You could have said, looked the kid in the face, and said, “Go for it, kid, just like I did.” But you won't be able to say that because you didn't.So you can't.(Laughter)

你真的，真的想利用你的家庭，你真的想把你的伴侶，和你的孩子當成獄卒嗎？ 你其實可以這么跟你孩子講。當他／她說“我有個夢想”的時候，你可以說，面對你的孩子，說，“去追隨它吧，孩子，就像我那樣?！?但是你沒法那么說，因為你沒去追隨夢想。所以你不能那么說。（笑聲）

You're afraid to pursue your passion.You're afraid to look ridiculous [r??d?kj?l?s].You're afraid to try.You're afraid you may fail.Great friend, great spouse, great parent, great career.Is that not a package? How can you be one without the other? But you're afraid.你不敢去追求夢想。你害怕自己看起來像個瘋子。你不敢去嘗試。你害怕失敗。好朋友，好伴侶，好父母，偉業(yè)。不是打包在一起的嗎？你怎么能符合其中一個卻不符合另一個？ 但是你害怕。And that's why you're not going to have a great career, unless--unless, that most evocative [??vɑk?t?v] of all English words--unless.But the unless word is also attached

[??t?t?t] to that other, most terrifying ['ter?fa??] phrase [fre?z], ”If only I had...“ ”If only I had..." If you ever have that thought over and over again in your brain, it will hurt a lot.這就是為什么你不會成就偉業(yè)，除非－，除非，最引人回憶的詞－，除非。但是除非這個詞和另外一個，最可怕的短語是連著的，”如果我當初...“ ”如果我當初...“ 如果你曾經(jīng)有過這個想法在你腦海里回旋，它會特別傷人。

So, those are the many reasons why you are going to fail to have a great career, unless...所以，這些就是，你為什么不能成就偉業(yè)，的眾多原因。除非...，Unless.除非。

Thank you.(Applause)

謝謝。（掌聲），