新视野视听说第二册第四单元答案

1、Listening in task1The son wants to buy a pair of basketball as his old ones look kind of . But the father thinks there is still left in the old shoes. The son points out that in an Yao Ming claims that these shoes give him . The father, on the other hand, says that he does not make as much as Yao Mi

2、ng does, and that the tall man does not need extra spring. Whats more, the advertiser may give him for wearing the shoes in the ad. To this the son answers jokingly that he would wear the new shoes . Then the father replies that Yao Ming did not simply because of the shoes. Rather, there must be som

3、ething else. The son knows his father means things like and dedication. Finally the father asks the son to his studies and the shoes. Your answer Correct answer (1) shoes shoes (2) funny funny (3) a lot of life a lot of life (4) ad ad (5) extra spring extra spring (6) money money (7) dollers million

4、s of dollars (8) for nothing for nothing (9) reach the top reach the top (10) hard work hard work (11) focus on focus on (12) get forget 1. The firm has been asked to change the wording of its advertising because it prejudices against friendly people. (A) True (B) False 2. Travelco is looking for an

5、 employee to provide food for its staff. (A) True (B) False 3. Mr. Smith agreed to the decision to remove the word friendly from the advertisement. (A) True (B) False 4. The job center intends to set guidelines of not using personality characteristics in advertisements. (A) True (B) False 5. Accordi

6、ng to an official of the job center, the local judges will determine the results of the dispute. (A) True (B) False 1. How does the Pepsi commercial begin? (A) Shaq is playing basketball while a kid is looking on. (B) Shaq drinks Pepsi while a kid plays basketball. (C) Shaq and a kid are both drinki

7、ng Pepsi. (D) Shaq is teaching a kid to play basketball. 2. Why does Shaq walk toward the kid? (A) Because he wants to know if the kid admires him. (B) Because he wants to ask the kid for the Pepsi. (C) Because he is going to buy a Pepsi from the kid. (D) Because he likes the kid. 3. What is the Pep

8、si commercial trying to say? (A) The basketball star has a stronger appeal to the kid than anything else. (B) Pepsi has a stronger appeal to the kid than the basketball star does. (C) The kid likes basketball better than anything else. (D) Pepsi is better than Coca-Cola. 4. What is the Coca-Cola com

9、mercial trying to tell us? (A) Coke is more valuable than any other souvenir. (B) The boy likes Coke better than the football stars towel. (C) The football star likes Coke very much. (D) Coke is superior to other drinks. 5. What does the road sign in New York City mean? (A) While parking, dont think

10、 too much about anything else. (B) The road there is dangerous. (C) Parking there is not allowed. (D) Parking is permitted only beside the road sign. 窗体顶端1. An advertiser should begin with what benefits consumers can get. (A) True (B) False 2. In an advertisement you should use such pronouns as you,

11、 we and I, but not yours, ours and mine. (A) True (B) False 3. Both an extra number and a percentage can be used in an ad. (A) True (B) False 4. In an advertisement you should use many adverbs to modify verbs to convey a sense of action and urgency. (A) True (B) False 5. At the end of your ad, you n

12、eed to tell consumers what they should do next. (A) True (B) False 窗体底端1. What have many countries done to discourage smoking?They have completely. Your answer Correct answer banned tobacco ads banned tobacco ads / banned cigarette ads 2. What kind of tobacco advertising is not allowed in the United

13、 States?Advertisers are not allowed to show . Your answer Correct answer young people smoking cigarettes young people smoking cigarettes 3. What do advertisers do with the law against cigarette ads aimed at youth?They keep finding . Your answer Correct answer ways around the law ways around the law

14、4. Why do cigarette manufacturers want to target young people?They must keep bringing in , as the are dying of lung cancer. Your answer Correct answer (1) new customers new customers (2) old ones old ones 5. According to the woman, what should the Student Union do?It should do some publicity against

15、 . Your answer Correct answer smoking on campus smoking on campus 1. What is true of the contemporary business world? (A) Supply usually outnumbers demand. (B) Demand usually outnumbers supply. (C) Supply is usually equal to demand. (D) When supply exceeds demand, prices rise. 2. What is NOT mention

16、ed in the passage? (A) Manufacturers advertise their products in newspapers. (B) Manufacturers advertise their products through songs. (C) Manufacturers advertise their products by sponsoring sporting events. (D) Manufacturers advertise their products through salesgirls. 3. According to the passage,

17、 what is the most important means of advertising? (A) The cinema. (B) The television. (C) The newspaper. (D) The radio. 4. According to the passage, why can advertisements influence people? (A) Because ads are cleverly designed. (B) Because many people are eager to buy. (C) Because people like ads e

18、ven if they know ads may not be telling the truth. (D) Because people believe what ads say without thinking if the ads are true. 5. What is the passage discussing? (A) The importance of advertising. (B) Various ways of advertising. (C) The successes and failures of advertising. (D) The causes, metho

19、ds and effects of advertising.窗体顶端1. A small range of good-quality items is being sold at the store. (A) True (B) False 2. An easy rent-to-own plan probably means a plan to help customers rent something until finally they own it. (A) True (B) False 3. The maximum price of a digital piano is 399 doll

20、ars. (A) True (B) False 4. Major items are delivered free of charge. (A) True (B) False 5. The ad encourages customers to go further outside the city to find better and cheaper furniture. (A) True (B) False 窗体底端单元测试Part I Script Directions: Listen to the short dialogs, and then choose the correct an

21、swers to the questions. You will hear the recording twice. After the first playing, there will be time for you to choose the correct answers. Use the second playing to check your answers. 1.(Listen to the audio recording for the question.) A. Because short slogans are refreshing.B. Because short slo

22、gans can catch busy peoples attention. C. Because only short slogans are impressive. D. Because the Coca-Cola company has set a good example.2.(Listen to the audio recording for the question.) A. The man asks for some money to buy bread.B. The woman spends a lot of money shopping. C. The woman wants

23、 to buy some spring clothes for the man. D. The man is quite angry at the woman not buying him bread.3.(Listen to the audio recording for the question.) A. Ads should be made by local people. B. The lipstick ad is more effective in Germany.C. Ads should be adapted for particular places. D. The same

24、ad can be used in various places.4.(Listen to the audio recording for the question.) A. To show how fast one can buy things with the card. B. To show how much he likes the card. C. To express his disagreement with the woman.D. To express his agreement with the woman.5.(Listen to the audio recording

25、for the question.) A. She is a loyal customer to Nokia. B. She is a loyal customer to Ericsson.C. She is easily influenced by advertisements. D. She is a tough consumer.Part II Script Directions: Listen to the following recording, and then fill in the blanks with the missing words. You will hear the

26、 recording twice. After the first playing, there will be time to write the missing words. Use the second playing to check your answers. W:So, Mr. Smith, you want to increase ridership on the buses.M:(1), and we hope you can help us.W:Certainly we can. First, we must (2) of bus travel.M:How do you do

27、 that?W:Well, well (3) to see what people really think about taking the bus. Well investigate (4) and so on.M:Will that work?W:It works (5). Once we get a profile of (6), we can see who we can (7).Your answerCorrect answer(1)We doWe do(2)change the imagechange the image(3)do some survicedo some surv

28、eys(4)different datesdifferent age groups(5)all the timeall the time(6)usersyour users(7)target ittargetPart III Script Directions: Listen to the following recording, and then choose the correct answers to the questions. You will hear the recording twice. After the first playing, there will be time

29、for you to choose the correct answers. Use the second playing to check your answers. 1.Which of the following is NOT mentioned as a purpose of advertising? A. To encourage listeners to buy a product. B. To persuade readers to support an organization.C. To encourage readers to get rid of a certain id

30、ea. D. To persuade listeners to agree with a certain idea.2.According to the passage, who is most likely to pay for an ad?A. The advertiser. B. An advertising agency. C. The retailer. D. The shop.3.Which of the following is second in importance?A. Local advertising. B. Trade advertising. C. National

31、 advertising. D. Professional advertising.4.Which of the following is true of direct mail?A. Mail advertisements go to people with certain characteristics. B. Mail advertisements go to producers rather than professionals. C. Mail advertisements are more effective than TV commercials. D. Mail adverti

32、sements are more expensive than other forms of advertisements.5.What is the passage mainly talking about? A. The role of advertising in modern society.B. The definition and classification of ads. C. The effects of various types of ads. D. The importance of various types of ads.Part IVDirections: Cho

33、ose the best answer to each of the following statements. 1.Dad, I need some new shoes. My old ones look _ funny. A. kind B. a kindC. kind of D. a kind of2.They probably give Yao Ming millions of dollars to wear those shoes. But if you bought me the shoes, Id wear them _. A. nothing B. with nothing C

34、. in nothingD. for nothing3.In the States, advertisers are not allowed _ young people smoking cigarettes. A. show B. showingC. to show D. to be shown4.Cigarette manufacturers need to keep _ new customers. A. bringing about B. bringing to C. bringing forwardD. bringing in5.Manufacturers often spend l

35、arge _ of money on the advertisements. A. volumes B. numbersC. sums D. dollars6.Dont _ think about it! is an expression commonly used in the United States when a person emphatically denies another person something.A. so B. reallyC. even D. ever7.It is _ for us to specify what kind of people we want.

36、A. too only naturalB. only too natural C. too natural only D. only natural too8.Advertisers keep finding ways _ the law. A. overB. about C. roundD. around9.Our student union should _ against smoking on campus. A. make some publicityB. do some publicity C. make some publication D. do some publication

37、10.We have everything you need. Stereos, video machines, refrigerators, dining room tables. _; we have it. A. Naming itB. To name itC. You name it D. You put a name on it永磁交流伺服电机位置反馈传感器检测相位与电机磁极相位的对齐方式2008-11-07来源：internet浏览：504 主流的伺服电机位置反馈元件包括增量式编码器，绝对式编码器，正余弦编码器，旋转变压器等。为支持永磁交流伺服驱动的矢量控制，这些位置反馈元件就必须

38、能够为伺服驱动器提供永磁交流伺服电机的永磁体磁极相位，或曰电机电角度信息，为此当位置反馈元件与电机完成定位安装时，就有必要调整好位置反馈元件的角度检测相位与电机电角度相位之间的相互关系，这种调整可以称作电角度相位初始化，也可以称作编码器零位调整或对齐。下面列出了采用增量式编码器，绝对式编码器，正余弦编码器，旋转变压器等位置反馈元件的永磁交流伺服电机的传感器检测相位与电机电角度相位的对齐方式。增量式编码器的相位对齐方式 在此讨论中，增量式编码器的输出信号为方波信号，又可以分为带换相信号的增量式编码器和普通的增量式编码器，普通的增量式编码器具备两相正交方波脉冲输出信号A和B，以及零位信号Z；带换相

39、信号的增量式编码器除具备ABZ输出信号外，还具备互差120度的电子换相信号UVW，UVW各自的每转周期数与电机转子的磁极对数一致。带换相信号的增量式编码器的UVW电子换相信号的相位与转子磁极相位，或曰电角度相位之间的对齐方法如下： 1.用一个直流电源给电机的UV绕组通以小于额定电流的直流电，U入，V出，将电机轴定向至一个平衡位置； 2.用示波器观察编码器的U相信号和Z信号； 3.调整编码器转轴与电机轴的相对位置； 4.一边调整，一边观察编码器U相信号跳变沿，和Z信号，直到Z信号稳定在高电平上（在此默认Z信号的常态为低电平），锁定编码器与电机的相对位置关系； 5.来回扭转电机轴，撒手后，若电机轴

40、每次自由回复到平衡位置时，Z信号都能稳定在高电平上，则对齐有效。 撤掉直流电源后，验证如下： 1.用示波器观察编码器的U相信号和电机的UV线反电势波形； 2.转动电机轴，编码器的U相信号上升沿与电机的UV线反电势波形由低到高的过零点重合，编码器的Z信号也出现在这个过零点上。 上述验证方法，也可以用作对齐方法。 需要注意的是，此时增量式编码器的U相信号的相位零点即与电机UV线反电势的相位零点对齐，由于电机的U相反电势，与UV线反电势之间相差30度，因而这样对齐后，增量式编码器的U相信号的相位零点与电机U相反电势的-30度相位点对齐，而电机电角度相位与U相反电势波形的相位一致，所以此时增量式编码器

41、的U相信号的相位零点与电机电角度相位的-30度点对齐。 有些伺服企业习惯于将编码器的U相信号零点与电机电角度的零点直接对齐，为达到此目的，可以： 1.用3个阻值相等的电阻接成星型，然后将星型连接的3个电阻分别接入电机的UVW三相绕组引线； 2.以示波器观察电机U相输入与星型电阻的中点，就可以近似得到电机的U相反电势波形； 3.依据操作的方便程度，调整编码器转轴与电机轴的相对位置，或者编码器外壳与电机外壳的相对位置； 4.一边调整，一边观察编码器的U相信号上升沿和电机U相反电势波形由低到高的过零点，最终使上升沿和过零点重合，锁定编码器与电机的相对位置关系，完成对齐。 由于普通增量式编码器不具备U

42、VW相位信息，而Z信号也只能反映一圈内的一个点位，不具备直接的相位对齐潜力，因而不作为本讨论的话题。 绝对式编码器的相位对齐方式 绝对式编码器的相位对齐对于单圈和多圈而言，差别不大，其实都是在一圈内对齐编码器的检测相位与电机电角度的相位。早期的绝对式编码器会以单独的引脚给出单圈相位的最高位的电平，利用此电平的0和1的翻转，也可以实现编码器和电机的相位对齐，方法如下： 1.用一个直流电源给电机的UV绕组通以小于额定电流的直流电，U入，V出，将电机轴定向至一个平衡位置； 2.用示波器观察绝对编码器的最高计数位电平信号； 3.调整编码器转轴与电机轴的相对位置； 4.一边调整，一边观察最高计数位信号的

43、跳变沿，直到跳变沿准确出现在电机轴的定向平衡位置处，锁定编码器与电机的相对位置关系； 5.来回扭转电机轴，撒手后，若电机轴每次自由回复到平衡位置时，跳变沿都能准确复现，则对齐有效。 这类绝对式编码器目前已经被采用EnDAT，BiSS，Hyperface等串行协议，以及日系专用串行协议的新型绝对式编码器广泛取代，因而最高位信号就不符存在了，此时对齐编码器和电机相位的方法也有所变化，其中一种非常实用的方法是利用编码器内部的EEPROM，存储编码器随机安装在电机轴上后实测的相位，具体方法如下： 1.将编码器随机安装在电机上，即固结编码器转轴与电机轴，以及编码器外壳与电机外壳； 2.用一个直流电源给电

44、机的UV绕组通以小于额定电流的直流电，U入，V出，将电机轴定向至一个平衡位置； 3.用伺服驱动器读取绝对编码器的单圈位置值，并存入编码器内部记录电机电角度初始相位的EEPROM中； 4.对齐过程结束。 由于此时电机轴已定向于电角度相位的-30度方向，因此存入的编码器内部EEPROM中的位置检测值就对应电机电角度的-30度相位。此后，驱动器将任意时刻的单圈位置检测数据与这个存储值做差，并根据电机极对数进行必要的换算，再加上-30度，就可以得到该时刻的电机电角度相位。这种对齐方式需要编码器和伺服驱动器的支持和配合方能实现，日系伺服的编码器相位之所以不便于最终用户直接调整的根本原因就在于不肯向用户提

45、供这种对齐方式的功能界面和操作方法。这种对齐方法的一大好处是，只需向电机绕组提供确定相序和方向的转子定向电流，无需调整编码器和电机轴之间的角度关系，因而编码器可以以任意初始角度直接安装在电机上，且无需精细，甚至简单的调整过程，操作简单，工艺性好。 如果绝对式编码器既没有可供使用的EEPROM，又没有可供检测的最高计数位引脚，则对齐方法会相对复杂。如果驱动器支持单圈绝对位置信息的读出和显示，则可以考虑： 1.用一个直流电源给电机的UV绕组通以小于额定电流的直流电，U入，V出，将电机轴定向至一个平衡位置； 2.利用伺服驱动器读取并显示绝对编码器的单圈位置值； 3.调整编码器转轴与电机轴的相对位置；

46、 4.经过上述调整，使显示的单圈绝对位置值充分接近根据电机的极对数折算出来的电机-30度电角度所应对应的单圈绝对位置点，锁定编码器与电机的相对位置关系； 5.来回扭转电机轴，撒手后，若电机轴每次自由回复到平衡位置时，上述折算位置点都能准确复现，则对齐有效。 如果用户连绝对值信息都无法获得，那么就只能借助原厂的专用工装，一边检测绝对位置检测值，一边检测电机电角度相位，利用工装，调整编码器和电机的相对角位置关系，将编码器相位与电机电角度相位相互对齐，然后再锁定。这样一来，用户就更加无从自行解决编码器的相位对齐问题了。 个人推荐采用在EEPROM中存储初始安装位置的方法，简单，实用，适应性好，便于向

47、用户开放，以便用户自行安装编码器，并完成电机电角度的相位整定。 正余弦编码器的相位对齐方式 普通的正余弦编码器具备一对正交的sin，cos 1Vp-p信号，相当于方波信号的增量式编码器的AB正交信号，每圈会重复许许多多个信号周期，比如2048等；以及一个窄幅的对称三角波Index信号，相当于增量式编码器的Z信号，一圈一般出现一个；这种正余弦编码器实质上也是一种增量式编码器。另一种正余弦编码器除了具备上述正交的sin、cos信号外，还具备一对一圈只出现一个信号周期的相互正交的1Vp-p的正弦型C、D信号，如果以C信号为sin，则D信号为cos，通过sin、cos信号的高倍率细分技术，不仅可以使正

48、余弦编码器获得比原始信号周期更为细密的名义检测分辨率，比如2048线的正余弦编码器经2048细分后，就可以达到每转400多万线的名义检测分辨率，当前很多欧美伺服厂家都提供这类高分辨率的伺服系统，而国内厂家尚不多见；此外带C、D信号的正余弦编码器的C、D信号经过细分后，还可以提供较高的每转绝对位置信息，比如每转2048个绝对位置，因此带C、D信号的正余弦编码器可以视作一种模拟式的单圈绝对编码器。 采用这种编码器的伺服电机的初始电角度相位对齐方式如下： 1.用一个直流电源给电机的UV绕组通以小于额定电流的直流电，U入，V出，将电机轴定向至一个平衡位置； 2.用示波器观察正余弦编码器的C信号波形；

49、3.调整编码器转轴与电机轴的相对位置； 4.一边调整，一边观察C信号波形，直到由低到高的过零点准确出现在电机轴的定向平衡位置处，锁定编码器与电机的相对位置关系； 5.来回扭转电机轴，撒手后，若电机轴每次自由回复到平衡位置时，过零点都能准确复现，则对齐有效。 撤掉直流电源后，验证如下： 1.用示波器观察编码器的C相信号和电机的UV线反电势波形； 2.转动电机轴，编码器的C相信号由低到高的过零点与电机的UV线反电势波形由低到高的过零点重合。 这种验证方法，也可以用作对齐方法。 此时C信号的过零点与电机电角度相位的-30度点对齐。如果想直接和电机电角度的0度点对齐，可以考虑： 1.用3个阻值相等的电

50、阻接成星型，然后将星型连接的3个电阻分别接入电机的UVW三相绕组引线； 2.以示波器观察电机U相输入与星型电阻的中点，就可以近似得到电机的U相反电势波形； 3.调整编码器转轴与电机轴的相对位置； 4.一边调整，一边观察编码器的C相信号由低到高的过零点和电机U相反电势波形由低到高的过零点，最终使2个过零点重合，锁定编码器与电机的相对位置关系，完成对齐。 由于普通正余弦编码器不具备一圈之内的相位信息，而Index信号也只能反映一圈内的一个点位，不具备直接的相位对齐潜力，因而在此也不作为讨论的话题。 如果可接入正余弦编码器的伺服驱动器能够为用户提供从C、D中获取的单圈绝对位置信息，则可以考虑： 1.

51、用一个直流电源给电机的UV绕组通以小于额定电流的直流电，U入，V出，将电机轴定向至一个平衡位置； 2.利用伺服驱动器读取并显示从C、D信号中获取的单圈绝对位置信息； 3.调整旋变轴与电机轴的相对位置； 4.经过上述调整，使显示的绝对位置值充分接近根据电机的极对数折算出来的电机-30度电角度所应对应的绝对位置点，锁定编码器与电机的相对位置关系； 5.来回扭转电机轴，撒手后，若电机轴每次自由回复到平衡位置时，上述折算绝对位置点都能准确复现，则对齐有效。 此后可以在撤掉直流电源后，得到与前面基本相同的对齐验证效果： 1.用示波器观察正余弦编码器的C相信号和电机的UV线反电势波形； 2.转动电机轴，验

52、证编码器的C相信号由低到高的过零点与电机的UV线反电势波形由低到高的过零点重合。 如果利用驱动器内部的EEPROM等非易失性存储器，也可以存储正余弦编码器随机安装在电机轴上后实测的相位，具体方法如下： 1.将正余弦随机安装在电机上，即固结编码器转轴与电机轴，以及编码器外壳与电机外壳； 2.用一个直流电源给电机的UV绕组通以小于额定电流的直流电，U入，V出，将电机轴定向至一个平衡位置； 3.用伺服驱动器读取由C、D信号解析出来的单圈绝对位置值，并存入驱动器内部记录电机电角度初始安装相位的EEPROM等非易失性存储器中； 4.对齐过程结束。 由于此时电机轴已定向于电角度相位的-30度方向，因此存入的驱动器内部EEPROM等非易失性存储器中的位置检测值就对应电机电角度的-30度相位。此后，