超聲波測(cè)距儀外文獻(xiàn)翻譯

1、<p>　　本科畢業(yè)設(shè)計(jì)(論文)</p><p>　　外文翻譯（附外文原文）</p><p>　　學(xué) 院： </p><p>　　課題名稱： 超聲波測(cè)距系統(tǒng) </p><p>　　專業(yè)(方向)： 自動(dòng)化（控制） </p><p>　　班 級(jí)：

2、 </p><p>　　學(xué) 生： </p><p>　　指導(dǎo)教師： </p><p>　　日 期： 2013年 4月26日 </p><p><b>　　研究文章：</b></p><p><

3、b>　　超聲波測(cè)距儀</b></p><p>　　文件類型和數(shù)目：美國(guó)專利5442592 </p><p>　　摘要：提出了一種超聲波測(cè)距儀來抵消的溫度和濕度引起的變化，包括測(cè)量單元和參考標(biāo)準(zhǔn)。每一個(gè)單元產(chǎn)生重復(fù)的一系列脈沖，每一次重復(fù)直接關(guān)系到發(fā)射機(jī)和接收機(jī)之間的距離。脈沖串提供給各自的計(jì)數(shù)器，然后利用計(jì)數(shù)器所測(cè)得的數(shù)據(jù)進(jìn)行距離的測(cè)量。 </p><

4、p>　　出版日期： 1995年8月15日</p><p>　　主審查員：羅保.伊恩j. </p><p><b>　　背景發(fā)明</b></p><p>　　本發(fā)明涉及到儀器的測(cè)量距離，更特別是，這種儀器傳送超聲波于兩點(diǎn)之間。 精密機(jī)器設(shè)備必須校準(zhǔn)。在過去，這已經(jīng)可以利用卡鉗，微米等工具來校準(zhǔn)機(jī)械設(shè)備。不過，使用這些工具都不能實(shí)現(xiàn)自動(dòng)化。據(jù)

5、了解，該兩點(diǎn)之間距離可以通過測(cè)量波在兩點(diǎn)之間的傳播時(shí)間來確定。這樣一個(gè)類型的波可以是是一種超聲波，或聲，或波。當(dāng)超聲波傳播于兩點(diǎn)之間的時(shí)候，兩個(gè)點(diǎn)之間的距離可以通過由超聲波波速乘以超聲波傳播的時(shí)間，在合適的分離的兩點(diǎn)。因此，這是一個(gè)發(fā)明提供儀器利用超聲波準(zhǔn)確測(cè)量?jī)牲c(diǎn)之間距離的方法。 </p><p>　　當(dāng)距離適當(dāng)?shù)膬蓚€(gè)點(diǎn)之間的介質(zhì)是空氣的時(shí)候，聲速只取決于溫度和空氣相對(duì)濕度。因此，這個(gè)發(fā)明的進(jìn)一步目標(biāo)是，目前的

6、發(fā)明提供儀器的方法如所描述的一樣是獨(dú)立于溫度和濕度的變化的。 </p><p><b>　　綜述發(fā)明</b></p><p>　　前述的和額外的目標(biāo)已經(jīng)實(shí)現(xiàn)了根據(jù)這些原則的這項(xiàng)發(fā)明提供距離測(cè)量?jī)x器，其中包括一個(gè)參考的單元和測(cè)量單元。參考和測(cè)量單元是相同的，每個(gè)單元都包括了一個(gè)電聲波的發(fā)射機(jī)和接收機(jī)。參考單元的發(fā)射器和接收器之間的間隔是一個(gè)固定的參考距離，然而測(cè)量單元的

7、發(fā)射機(jī)和接收機(jī)的間距才是我們所要測(cè)量的部分。在每一個(gè)單元中，發(fā)射機(jī)和接收機(jī)都連接了一個(gè)反饋環(huán)路，以使發(fā)射機(jī)產(chǎn)生能由接收器接收的聲波生脈沖，然后由接收機(jī)轉(zhuǎn)換成一個(gè)電脈沖反饋到發(fā)射機(jī)，使產(chǎn)生一系列重復(fù)脈沖的結(jié)果。脈沖重復(fù)率是成反比關(guān)系發(fā)射器和接收器之間的距離。在每一個(gè)單元，脈沖被用來提供給一個(gè)計(jì)數(shù)器。由于參考的距離是已經(jīng)知道的了，所以計(jì)數(shù)器所輸出的數(shù)據(jù)被利用來確定所期望測(cè)得的距離。由于溫度和濕度的變化，這兩方面都會(huì)造成相同的影響，利用計(jì)數(shù)器

8、所提供的數(shù)據(jù)，這樣的測(cè)量對(duì)于溫度和濕度引起的變化一樣是沒有辦法避免的。 </p><p><b>　　簡(jiǎn)要圖紙說明</b></p><p>　　通過讀接了下來的說明前面的敘述將變得更加明顯，這個(gè)關(guān)于電路原理圖的描述在與這項(xiàng)發(fā)明的相關(guān)規(guī)律保持了相當(dāng)?shù)囊恢滦浴?</p><p><b>　　詳細(xì)說明</b></p>

9、<p>　　根據(jù)現(xiàn)在的繪圖，可以得出以下結(jié)論，測(cè)量單元10和參考單元12都聯(lián)結(jié)起來組成了可以利用的單元14 。測(cè)量單元10包括了一個(gè)電信號(hào)發(fā)射機(jī)16和一個(gè)電信號(hào)接收機(jī)18 。發(fā)射器16包括了夾著一對(duì)電極22和24的壓電材料20。同樣，接收機(jī)18包括了夾著一對(duì)電極28和30的壓電材料26。眾所周知，通過利用電極22和24之間產(chǎn)生的電場(chǎng)，壓電材料20將產(chǎn)生壓力 。如果該電場(chǎng)產(chǎn)生變化的話，例如通過利用一個(gè)電脈沖，就會(huì)產(chǎn)生一個(gè)聲波

10、32。因此，進(jìn)一步得知，當(dāng)聲波對(duì)接收器18起作用的時(shí)候 ，這時(shí)會(huì)引起接收器上的壓變材料26產(chǎn)生機(jī)械變形，同時(shí)產(chǎn)生一個(gè)電信號(hào)通過28和30這一對(duì)電極 。雖然已經(jīng)對(duì)壓電傳感器作出了說明，但是其他的電聲裝置也可利用，例如，有關(guān)靜電的，駐極體或電磁類型的。 </p><p>　　如圖所示，接收機(jī)的電極28和30將與放大器34的輸入端相連接，同時(shí)，放大器的其輸出端與探測(cè)器36相連接。探測(cè)器36被用于提供一個(gè)信號(hào)給脈沖發(fā)生器

11、38，當(dāng)放大器34的輸出已經(jīng)超過預(yù)定的等級(jí)。脈沖發(fā)生器38然后產(chǎn)生一個(gè)觸發(fā)脈沖，這是提供給脈沖發(fā)生器40 。在為了提高靈敏度，該系統(tǒng)的傳感器16和18歲通常情況下都是保持運(yùn)作的。根據(jù)相應(yīng)的需要，本發(fā)明提供了一個(gè)連續(xù)波振蕩器42，他能持續(xù)的產(chǎn)生一個(gè)固定頻率的連續(xù)振蕩信號(hào)，最好是同傳感器16和18能接收到的固定頻率一致 。這個(gè)振蕩信號(hào)被用來提供給調(diào)制器44 。為了使發(fā)射機(jī)16有效的工作 ，最好的做法是提供幾個(gè)周期的共振頻率信號(hào)，而不是一個(gè)單

12、脈沖或單周期。因此，在這里使用了脈沖發(fā)生器40，用于回應(yīng)每一個(gè)觸發(fā)脈沖，提供一個(gè)控制脈沖給調(diào)制器44，讓調(diào)制器44有一個(gè)與來自于振蕩器42的周期振蕩信號(hào)預(yù)定的相同時(shí)間 。這樣的控制脈沖能使調(diào)制器44傳送一個(gè)周期的突破口以觸發(fā)發(fā)射機(jī)16。 </p><p>　　當(dāng)電源被用于描述的電路，有相當(dāng)大的噪音輸入到放大器34 ，以至于其輸出觸發(fā)脈沖發(fā)生器40引起正當(dāng)周期變化，這個(gè)振蕩周期是用來提供給發(fā)射器16的電極22和24

13、。發(fā)射器16因此產(chǎn)生聲波32并作用于接收器18 。接收器18 然后產(chǎn)生一個(gè)電脈沖，輸入放大器的34 ，這再次觸發(fā)脈沖發(fā)生器40 。這個(gè)周期繼續(xù)循環(huán)，使重復(fù)的一系列觸發(fā)脈沖作用于脈沖發(fā)生器38的輸出 。這脈沖串被用于計(jì)數(shù)器46，以及脈沖發(fā)生器40 。 </p><p>　　發(fā)射機(jī)16和接收機(jī)18中間的間隔距離 D 它是我們想要測(cè)量的數(shù)據(jù)。傳播時(shí)間T是聲波傳播于之間的距離除以速度而得出來的，通過公式T=D/V 。速度

14、是在發(fā)射機(jī)16和接收機(jī)18之間這段空氣中傳播的速度，計(jì)數(shù)器46測(cè)量觸發(fā)脈沖的重復(fù)率，這是因?yàn)槊}沖等于的1/T。因此，重復(fù)率是等于V/D。聲波的速度通常受到空氣的濕度和溫度的影響，例子如下：##equ1##其中T是溫度，P是水汽局部的壓力，H是大氣壓強(qiáng)， γ和γ是比例不同壓力下在熱水汽和干燥的空氣不同的比熱容。因此，觸發(fā)脈沖的重復(fù)率測(cè)被計(jì)數(shù)器46測(cè)量得相當(dāng)?shù)臏?zhǔn)確 ，但是聲速受到溫度和濕度的影響，使測(cè)量的距離d無法被準(zhǔn)去的確定。 </

15、p><p>　　根據(jù)這項(xiàng)發(fā)明的基本原理，需要利用參考單元12 。參考單元12同測(cè)量單元10基本上是一樣的，其中，包括一電發(fā)射機(jī)50，以及在壓電材料52之間的一對(duì)電極的54和56 。接收機(jī)58 ，其中包括壓電材料60之間的一對(duì)電極62和64 。再次，傳感器除了其他類型壓電也可以被利用。發(fā)射機(jī)50和接收機(jī)58之間的距離都是已知的且固定的,設(shè)為DR。電極62和64連接到放大器66的輸入端 ，其輸出連接到探測(cè)器68 。探測(cè)器

16、68的輸出端連接到脈沖發(fā)生器70，脈沖發(fā)生器70產(chǎn)生觸發(fā)脈沖。觸發(fā)脈沖應(yīng)用到脈沖發(fā)生器72以控制調(diào)制器74通過連續(xù)振蕩器76傳送一段脈沖串傳遞至發(fā)射機(jī)50 。來自于脈沖發(fā)生器70的觸發(fā)脈沖也用于計(jì)數(shù)器78。 </p><p>　　最好是所有的傳感器16 ，18 ，50和58具有相同的共振頻率。因此，振蕩器42和76都工作在同樣的頻率上，脈沖發(fā)生器40和72產(chǎn)生相同帶寬的輸出脈沖。 </p><

17、p>　　按照慣例，測(cè)量單元10和參考單元12空間上很接近，使該聲速在這兩個(gè)單元是相同的。雖然測(cè)量單元10和參考單元12的脈沖重復(fù)率各自依賴于各自的溫度和濕度，能證明的距離D來衡量。可以得出測(cè)量單元和參考單元之間的聯(lián)系如下：i D=D R (1/t R )/(1/t)，tR是指的參照單元聲波傳播于固定空間的時(shí)間。這個(gè)關(guān)系與空氣的溫度和濕度都是無關(guān)的。 </p><p>　　因此，計(jì)數(shù)器46和計(jì)數(shù)器78的輸出

18、被用來提供來作為微處理器90，作為方法14。微處理器90可通過編寫程序來提供輸出。這個(gè)輸出與計(jì)數(shù)器46和78的輸出是成比例的，反過來也同測(cè)量單元10和參考單元12各自的觸發(fā)脈沖串成比例。如所敘述的一樣，這些比率是不依賴于溫度和濕度的，因?yàn)閰⒖季嚯xDR是已知的，提供了一個(gè)準(zhǔn)確的距離D的參考。這個(gè)利用方法12更進(jìn)一步的包括了被微處理器控制的顯示器92，所以設(shè)備可以確定距離D。</p><p>　　試驗(yàn)還表明當(dāng)發(fā)射機(jī)和

19、接收機(jī)傳感器之間的距離太小的時(shí)候，聲波的反射在傳感器表面的效果不是很明顯，以至于極大的影響了測(cè)量的精度。根據(jù)這種情況，使傳感器分開有一個(gè)相當(dāng)?shù)淖钚【嚯x，最合適是4英寸。</p><p>　　Research articles ：</p><p>　　Ultrasonic distance meter</p><p>　　Document Type and Numbe

20、r:United States Patent 5442592 </p><p>　　Abstract:An ultrasonic distance meter cancels out the effects of temperature and humidity variations , including a measuring unit and a reference standard. Each of th

21、e units produces a repetitive series of pulses. And each repetition is directly related to the distance between the electroacoustic transmitter and the electroacoustic receiver. The pulse trains are provided to respectiv

22、e counters, and then use the counter data measured by the distance measurement.</p><p>　　Publication Date:08/15/1995 </p><p>　　Primary Examiner:Lobo, Ian J.</p><p>　　BACKGROUND OF T

23、HE INVENTION </p><p>　　This invention relates to apparatus for the measurement of distance,and more particularly, to such apparatus which transmits ultrasonic waves between two points. </p><p>　

24、　Precision machinery and equipment must be calibrated. In the past, this has been accomplished utilizing mechanical devices such as calipers, micrometers etc. However, the use of these tools does not lend itself to reali

25、ze automation. It is known that the distance between two points can be determined by measuring the propagation time of the wave tramelling between those two points. Such a type of wave could be an ultrasonic, or acoustic

26、, or wave. When the ultrasonic wave travels between two point</p><p>　　When the medium between the two points whose distance is suitable is air, the velocity of sound is rested with the temperature and humid

27、ity of the air. Therefore, the further object of this invention is the present invention to provide apparatus of the type described which is independent of the variations of temperature and humidity . </p><p&g

28、t;　　SUMMARY OF THE INVENTION </p><p>　　The foregoing and additional objects are attained in accordance with the principles of this invention by providing distance measuring apparatus which includes a referen

29、ce unit and a measuring unit. The reference and measuring units are the same and each includes an electroacoustic transmitter and an electroacoustic receiver. The spacing between the transmitter and the receiver of the r

30、eference unit is a fixed reference distance, whereas the spacing between the transmitter and receiver of the mea</p><p>　　BRIEF DESCRIPTION OF THE DRAWINGS </p><p>　　The foregoing will be more r

31、eadily apparent upon reading the following description in conjunction with the drawing in which the single FIGURE schematically depicts apparatus constructed in accordance with the principles of this invention. </p>

32、;<p>　　DETAILED DESCRIPTION </p><p>　　Referring now to the drawing, there is shown a measuring unit 10 and a reference unit 12, both coupled to a utilization means 14. The measuring unit 10 includes a

33、n electroacoustic transmitter 16 and an electroacoustic receiver 18. The transmitter 16 includes piezoelectric material 20 sandwiched between a pair of electrodes 22 and 24. Likewise, the receiver 18 includes piezoelectr

34、ic material 26 sandwiched between a pair of electrodes 28 and 30. As is known, by applying an electric field across th</p><p>　　As shown, the electrodes 28 and 30 of the receiver 18 are coupled to the input

35、of an amplifier 34, whose output is coupled to the input of a detector 36. The detector 36 is arranged to provide a signal to the pulse former 38 when the output from the amplifier 34 exceeds a predetermined level. The p

36、ulse former 38 then generates a trigger pulse which is provided to the pulse generator 40. In order to enhance the sensitivity of the system, the transducers 16 and 18 are resonantly excited. There is </p><p&g

37、t;　　When electric power is applied to the described circuitry, there is sufficient noise at the input to the amplifier 34 that its output triggers the pulse generator 40 to cause a burst of oscillating cycles to be provi

38、ded across the electrodes 22 and 24 of the transmitter 16. The transmitter 16 accordingly generates an acoustic wave 32 which impinges upon the receiver 18. The receiver 18 then generates an electrical pulse which is app

39、lied to the input of the amplifier 34, which again causes trigge</p><p>　　The transmitter 16 and the receiver 18 are spaced apart by the distance "D" which it is desired to measure. The propagation

40、 time "t" for an acoustic wave 32 traveling between the transmitter 16 and the receiver 18 is given by: t=D/V s </p><p>　　where V s is the velocity of sound in the air between the transmitter 16 an

41、d the receiver 18. The counter 46 measures the repetition rate of the trigger pulses, which is equal to 1/t. Therefore, the repetition rate is equal to V s /D. The velocity of sound in air is a function of the temperatur

42、e and humidity of the air, as follows: ##EQU1## where T is the temperature, p is the partial pressure of the water vapor, H is the barometric pressure, Γ w and Γ a are the ratio of constant pressure specif</p><

43、;p>　　In accordance with the principles of this invention, a reference unit 12 is provided. The reference unit 12 is of the same construction as the measuring unit 10 and therefore includes an electroacoustic transmitt

44、er 50 which includes piezoelectric material 52 sandwiched between a pair of electrodes 54 and 56, and an electroacoustic receiver 58 which includes piezoelectric material 60 sandwiched between a pair of electrodes 62 and

45、 64. Again, transducers other than the piezoelectric type can be uti</p><p>　　Preferably, all of the transducers 16, 18, 50 and 58 have the same resonant frequency. Therefore, the oscillators 42 and 76 both

46、operate at that frequency and the pulse generators 40 and 72 provide equal width output pulses. </p><p>　　In usage, the measuring unit 10 and the reference unit 12 are in close proximity so that the sound ve

47、locity in both of the units is the same. Although the repetition rates of the pulses in the measuring unit 10 and the reference unit 12 are each temperature and humidity dependent, it can be shown that the distance D to

48、be measured is related to the reference distance D R as follows: i D=D R (1/t R )/(1/t) where t R is the propagation time over the distance D R in the reference unit 12. This rela</p><p>　　Thus, the outputs

49、of the counters 46 and 78 are provided as inputs to the microprocessor 90 in the utilization means 14. The microprocessor 90 is appropriately programmed to provide an output which is proportional to the ratio of the outp

50、uts of the counters 46 and 78, which in turn are proportional to the repetition rates of the respective trigger pulse trains of the measuring unit 10 and the reference unit 12. As described, this ratio is independent of

51、temperature and humidity and, since the re</p><p>　　Experiments have shown that when the distance between the transmitting and receiving transducers is too small, reflections of the acoustic wave at the tran

52、sducer surfaces has a not insignificant effect which degrades the measurement accuracy. Accordingly, it is preferred that each transducer pair be separated by at least a certain minimum distance, preferably about four in