外文翻譯---超聲波測距儀

1、<p><b>　　淮 陰 工 學(xué) 院</b></p><p>　　畢業(yè)設(shè)計(論文)外文資料翻譯</p><p>　　注：請將該封面與附件裝訂成冊。附件1：外文資料翻譯譯文</p><p><b>　　超聲波測距儀</b></p><p>　　文件類型和數(shù)目：美國專利5442592 <

2、;/p><p>　　摘要：提出了一種可以抵消溫度的影響和濕度的變化的新型超聲波測距儀，包括測量單元和參考資料。在每一個單位，重復(fù)的一系列脈沖的產(chǎn)生，每有一個重復(fù)率，直接關(guān)系到各自之間的距離，發(fā)射機和接收機。該脈沖序列提供給各自的計數(shù)器，計數(shù)器的產(chǎn)出的比率，是用來確定被測量的距離。 </p><p>　　出版日期：1995年8月15日</p><p>　　主審查員：羅保.

3、伊恩j. </p><p><b>　　一、背景發(fā)明</b></p><p>　　本發(fā)明涉及到儀器的測量距離，最主要的是，這種儀器，其中兩點之間傳輸超聲波。精密機床必須校準(zhǔn)。在過去，這已經(jīng)利用機械設(shè)備來完成，如卡鉗，微米尺等。不過，使用這種裝置并不利于本身的自動化技術(shù)發(fā)展。據(jù)了解，兩點之間的距離可以通過測量兩點之間的行波傳播時間的決定。這樣的一個波浪型是一種超聲波，或

4、聲波。當(dāng)超聲波在兩點之間通過時，兩點之間的距離可以由波的速度乘以測量得到的在分離的兩點中波中轉(zhuǎn)的時間。因此，本發(fā)明提供儀器利用超聲波來精確測量兩點之間的距離對象。</p><p>　　當(dāng)任意兩點之間的介質(zhì)是空氣時，聲音的速度取決于溫度和空氣的相對濕度。因此，它是進(jìn)一步的研究對象，本次的發(fā)明，提供的是獨立于溫度和濕度的變化的新型儀器。 </p><p><b>　　綜述發(fā)明<

5、/b></p><p>　　這項距離測量儀器發(fā)明是根據(jù)上述的一些條件和額外的一些基礎(chǔ)原則完成的，其中包括一個參考單位和測量單位。參考和測量單位是相同的，每個包括一個超聲波發(fā)射機和一個接收機。間隔發(fā)射器和接收器的參考值是一個固定的參考距離，而間距之間的發(fā)射機和接收機的測量單位是有最小距離來衡量的。在每一個單位，發(fā)射器和接收器耦合的一個反饋回路，它會導(dǎo)致發(fā)射器產(chǎn)生超聲脈沖，這是由接收器和接收到一個電脈沖然后被反

6、饋到發(fā)射機轉(zhuǎn)換，從而使重復(fù)系列脈沖的結(jié)果。重復(fù)率脈沖是成反比關(guān)系之間的距離發(fā)射器和接收器。在每一個單位，脈沖提供一個反饋。由于參考的距離是眾所周知的聲速，比例反產(chǎn)出是利用數(shù)學(xué)以確定所期望的距離來衡量。由于這兩方面都是相同的影響，溫度和濕度的變化，采取的比例相同，由此產(chǎn)生的測量變得準(zhǔn)確。 </p><p><b>　　三、詳細(xì)說明</b></p><p>　　(一)超聲

7、波測距原理 </p><p>　　1、壓電式超聲波發(fā)生器原理</p><p>　　壓電式超聲波發(fā)生器實際上是利用壓電晶體的諧振來工作的。超聲波發(fā)生器內(nèi)部結(jié)構(gòu)如下所示，它有兩個壓電晶片和一個共振板。當(dāng)它的兩極外加脈沖信號，其頻率等于壓電晶片的固有振蕩頻率時，壓電晶片將會發(fā)生共振，并帶動共振板振動，便產(chǎn)生超聲波。反之，如果兩電極間未外加電壓，當(dāng)共振板接收到超聲波時，將壓迫壓電晶片作振動，將機

8、械能轉(zhuǎn)換為電信號，這時它就成為超聲波接收器了。</p><p>　　測量脈沖到達(dá)時間的傳統(tǒng)方法是以擁有固定參數(shù)的接收信號開端為基礎(chǔ)的。這個界限恰恰選于噪音水平之上，然而脈沖到達(dá)時間被定義為脈沖信號剛好超過界限的第一時刻。一個物體的脈沖強度很大程度上取決于這個物體的自然屬性尺寸還有它與傳感器的距離。進(jìn)一步說，從脈沖起始點到剛好超過界限之間的時間段隨著脈沖的強度而改變。結(jié)果，一種錯誤便出現(xiàn)了——兩個擁有不同強度的脈沖

9、在不同時間超過界限卻在同一時間到達(dá)。強度較強的脈沖會比強度較弱的脈沖超過界限的時間早點，因此我們會認(rèn)為強度較強的脈沖屬于較近的物體。</p><p><b>　　2、超聲波測距原理</b></p><p>　　超聲波發(fā)射器向某一方向發(fā)射超聲波，在發(fā)射時刻的同時開始計時，超聲波在空氣中傳播，途中碰到障礙物就立即返回來，超聲波接收器收到反射波就立即停止計時。超聲波在空氣中

10、的傳播速度為340m/s，根據(jù)計時器記錄的時間t，就可以計算出發(fā)射點距障礙物的距離(s)，即：s=340t/2</p><p>　　二 超聲波測距系統(tǒng)的電路設(shè)計</p><p>　　系統(tǒng)的特點是利用單片機控制超聲波的發(fā)射和對超聲波自發(fā)射至接收往返時間的計時，單片機選用8751，經(jīng)濟(jì)易用，且片內(nèi)有4K的ROM，便于編程。電路原理圖如圖所示。其中只畫出前方測距電路的接線圖，左側(cè)和右側(cè)測距電路與

11、前方測距電路相同，故省略之。</p><p>　　1、40kHz脈沖的產(chǎn)生與超聲波發(fā)射</p><p>　　測距系統(tǒng)中的超聲波傳感器采用UCM40的壓電陶瓷傳感器，它的工作電壓是40kHz的脈沖信號，這由單片機執(zhí)行下面程序來產(chǎn)生。</p><p>　　puzel： mov 14h, #12h； 超聲波發(fā)射持續(xù)200ms</p><p&

12、gt;　　here： cpl p1.0 ； 輸出40kHz方波</p><p><b>　　nop ；</b></p><p><b>　　nop ；</b></p><p><b>　　nop ；</b></p><p>　　djnz 14h，here；

13、</p><p><b>　　ret</b></p><p>　　前方測距電路的輸入端接單片機P1.0端口，單片機執(zhí)行上面的程序后，在P1.0端口輸出一個40kHz的脈沖信號，經(jīng)過三極管T放大，驅(qū)動超聲波發(fā)射頭UCM40T，發(fā)出40kHz的脈沖超聲波，且持續(xù)發(fā)射200ms。右側(cè)和左側(cè)測 距電路的輸入端分別接P1.1和P1.2端口，工作原理與前方測距電路相同。</

14、p><p>　　2、超聲波的接收與處理</p><p>　　接收頭采用與發(fā)射頭配對的UCM40R，將超聲波調(diào)制脈沖變?yōu)榻蛔冸妷盒盘?，?jīng)運算放大器IC1A和IC1B兩極放大后加至IC2。IC2是帶有鎖 定環(huán)的音頻譯碼集成塊LM567，內(nèi)部的壓控振蕩器的中心頻率f0=1/1.1R8C3，電容C4決定其鎖定帶寬。調(diào)節(jié)R8在發(fā)射的載頻上，則LM567輸入信號大于25mV，輸出端8腳由高電平躍變?yōu)榈碗娖?/p>

15、，作為中斷請求信號，送至單片機處理。</p><p>　　前方測距電路的輸出端接單片機INT0端口，中斷優(yōu)先級最高，左、右測距電路的輸出通過與門IC3A的輸出接單片機INT1端口，同時單片機P1.3和P1.4接到IC3A的輸入端，中斷源的識別由程序查詢來處理，中斷優(yōu)先級為先右后左。部分源程序如下：</p><p>　　receive1：push psw</p><p&g

16、t;<b>　　push acc</b></p><p>　　clr ex1 ； 關(guān)外部中斷1</p><p>　　jnb p1.1, right ； P1.1引腳為0,轉(zhuǎn)至右測距電路中斷服務(wù)程序</p><p>　　jnb p1.2, left ； P1.2引腳為0,轉(zhuǎn)至左測距電路中斷服務(wù)程序</p>

17、<p>　　return： SETB EX1； 開外部中斷1</p><p><b>　　pop acc</b></p><p><b>　　pop psw</b></p><p><b>　　reti</b></p><p>　　right：

18、 ... ； 右測距電路中斷服務(wù)程序入口</p><p>　　ajmp return</p><p>　　left： ... ； 左測距電路中斷服務(wù)程序入口</p><p>　　ajmp return</p><p>　　3、計算超聲波傳播時

19、間</p><p>　　在啟動發(fā)射電路的同時啟動單片機內(nèi)部的定時器T0，利用定時器的計數(shù)功能記錄超聲波發(fā)射的時間和收到反射波的時間。當(dāng)收到超聲波反射波時，接收電路 輸出端產(chǎn)生一個負(fù)跳變，在INT0或INT1端產(chǎn)生一個中斷請求信號，單片機響應(yīng)外部中斷請求，執(zhí)行外部中斷服務(wù)子程序，讀取時間差，計算距離。其部分源程序如下：</p><p>　　RECEIVE0： PUSH PSW</p&g

20、t;<p><b>　　PUSH ACC</b></p><p>　　CLR EX0 ； 關(guān)外部中斷0</p><p>　　MOV R7, TH0 ； 讀取時間值</p><p>　　MOV R6, TL0</p><p><b>　　CLR C</b&g

21、t;</p><p><b>　　MOV A, R6</b></p><p>　　SUBB A, #0BBH； 計算時間差</p><p>　　MOV 31H, A ； 存儲結(jié)果</p><p><b>　　MOV A, R7</b></p><p&g

22、t;　　SUBB A, #3CH</p><p>　　MOV 30H, A</p><p>　　SETB EX0 ； 開外部中斷0</p><p><b>　　POP ACC</b></p><p><b>　　POP PSW</b></p><p>&l

23、t;b>　　RETI</b></p><p>　　對于一個平坦的目標(biāo)，距離測量包括兩個階段:粗糙的測量和精細(xì)測量。</p><p>　　第一步：脈沖的傳送產(chǎn)生一種簡單的超聲波。</p><p>　　第二步：根據(jù)公式改變回波放大器的獲得量直到回?fù)鼙粰z測到。</p><p>　　第三步：檢測兩種回波的振幅與過零時間。</p

24、><p>　　第四步：設(shè)置回波放大器的所得來規(guī)格輸出，假定是3伏。通過脈沖的周期設(shè)置下一個脈沖。根據(jù)第二部的數(shù)據(jù)設(shè)定時間窗。</p><p>　　第五步：發(fā)射兩串脈沖產(chǎn)生干擾波。測量過零時間與回波的振幅。如果逆向發(fā)生在回波中，決定要不通過在低氣壓插入振幅。</p><p>　　第六步：通過公式計算距離y。</p><p>　　四、超聲波測距系統(tǒng)的

25、軟件設(shè)計</p><p>　　軟件分為兩部分，主程序和中斷服務(wù)程序，如圖3（a）（b）(c) 所示。主程序完成初始化工作、各路超聲波發(fā)射和接收順序的控制。</p><p>　　定時中斷服務(wù)子程序完成三方向超聲波的輪流發(fā)射，外部中斷服務(wù)子程序主要完成時間值的讀取、距離計算、結(jié)果的輸出等工作。</p><p>　　系統(tǒng)初始化后就啟動定時器T1從0開始計數(shù)，此時主程序進(jìn)入

26、等待，當(dāng)?shù)竭_(dá)定時時間時T1溢出進(jìn)入T1中斷服務(wù)子程序；在T1中斷服務(wù)子程序中將啟動一次新的超聲波發(fā)射，此時將在P1.0引腳上開始產(chǎn)生的方波，同時開啟定時器T0計時，為了避免直射波的繞射，需要延遲1ms后再開INT0中斷允許；INT0中斷允許打開后，若此時出現(xiàn)低電平則代表收到回波信號，將提出中斷請求進(jìn)入INT0中斷服務(wù)子程序，在INT0中斷服務(wù)子程序中將停止定時器T0計時，讀取定時器T0時間值到相應(yīng)的存儲區(qū)，同時設(shè)置接收成功標(biāo)志；主程序一

27、旦檢測到接收成功標(biāo)志，將調(diào)用測溫子程序，采集超聲波測距時的環(huán)境溫度，并換算出準(zhǔn)確的聲速，存儲到RAM存儲單元中；單片機再調(diào)用距離計算子程序進(jìn)行計算，計算出傳感器到目標(biāo)物體之間的距離；此后主程序調(diào)用顯示子程序進(jìn)行顯示；當(dāng)一次發(fā)射、接收、顯示的過程完成后，系統(tǒng)將延遲100ms重新讓T1置初值，再次啟動T1以溢出，進(jìn)入下一次測距。如果由于障礙物過遠(yuǎn)，超出量程，以致在T0溢出時尚未接收到回波，則顯示“ERROR”重新回到主流程進(jìn)入新一輪測試。&

28、lt;/p><p><b>　　五、結(jié)論</b></p><p>　　對所要求測量范圍30cm~200cm內(nèi)的平面物體做了多次測量發(fā)現(xiàn)，其最大誤差為0.5cm，且重復(fù)性好。可見基于單片機設(shè)計的超聲波測距系統(tǒng)具有硬件結(jié)構(gòu)簡單、工作可靠、測量誤差小等特點。因此，它不僅可用于移動機器人，還可用在其它檢測系統(tǒng)中。</p><p>　　思考：至于為什么接收不

29、用晶體管做放大電路呢，因為放大倍數(shù)搞不好，CX20106集成放大電路，還帶自動電平增益控制，放大倍數(shù)為76dB，中心頻率是38k到40k，剛好是超聲波傳感器的諧振頻率 。</p><p>　　附件2：外文原文（復(fù)印件）</p><p>　　Ultrasonic distance meter</p><p>　　Document Type and Number:Uni

30、ted States Patent 5442592 Abstract:An ultrasonic distance meter cancels out the effects of temperature and humidity variations by including a measuring unit and a reference unit. In each of the units, a repetitive serie

31、s of pulses is generated, each having a repetition rate directly related to the respective distance between an electroacoustic transmitter and an electroacoustic receiver. The pulse trains are provided to respective coun

32、ters, and the ratio of the count</p><p>　　Publication Date:08/15/1995 </p><p>　　Primary Examiner:Lobo, Ian J.</p><p>　　A.BACKGROUND OF THE INVENTION</p><p>　　This inv

33、ention relates to apparatus for the measurement of distance and, more particularly, to such apparatus which transmits ultrasonic waves between two points. </p><p>　　Precision machine tools must be calibrated

34、. In the past, this has been accomplished utilizing mechanical devices such as calipers, micrometers, and the like. However, the use of such devices does not readily lend itself to automation techniques. It is known that

35、 the distance between two points can be determined by measuring the propagation time of a wave travelling between those two points. One such type of wave is an ultrasonic, or acoustic, wave. When an ultrasonic wave trave

36、ls between two poi</p><p>　　When the medium between the two points whose spacing is being measured is air, the sound velocity is dependent upon the temperature and humidity of the air. It is therefore a furt

37、her object of the,present invention to provide apparatus of the type described which is independent of temperature and humidity variations. </p><p>　　B.SUMMARY OF THE INVENTION</p><p>　　The for

38、egoing and additional objects are attained in accordance with the principles of this invention by providing distance measuring apparatus which includes a reference unit and a measuring unit. The reference and measuring u

39、nits are the same and each includes an electroacoustic transmitter and an electroacoustic receiver. The spacing between the transmitter and the receiver of the reference unit is a fixed reference distance, whereas the sp

40、acing between the transmitter and receiver of the mea</p><p>　　C.DETAILED DESCRIPTION</p><p>　　A.principle of ultrasonic distance measurement </p><p>　　1, the principle of piezoelec

41、tric ultrasonic generator </p><p>　　Piezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work. Ultrasonic generator, the internal structure as shown in Figure 1, it has two pi

42、ezoelectric chip and a resonance plate. When it's two plus pulse signal, the frequency equal to the intrinsic piezoelectric oscillation frequency chip, the chip will happen piezoelectric resonance, and promote the de

43、velopment of plate vibration resonance, ultrasound is generated. Conversely, if the two are not inter-electrode v</p><p>　　The traditional way to determine the moment of the echo's arrival is based on th

44、resholding the received signal with a fixed reference. The threshold is chosen well above the noise level, whereas the moment of arrival of an echo is defined as the first moment the echo signal surpasses that threshold.

45、 The intensity of an echo reflecting from an object strongly depends on the object's nature, size and distance from the sensor. Further, the time interval from the echo's starting point to the moment </p>

46、<p>　　2, the principle of ultrasonic distance measurement </p><p>　　Ultrasonic transmitter in a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread

47、 of ultrasound in the air, obstacles on his way to return immediately, the ultrasonic reflected wave received by the receiver immediately stop the clock. Ultrasound in the air as the propagation velocity of 340m / s, acc

48、ording to the timer records the time t, we can calculate the distance between the launch distance barrier (s), that is: s = 340t / 2 </p><p>　　B.Ultrasonic Ranging System for the Second Circuit Design </p

49、><p>　　System is characterized by single-chip microcomputer to control the use of ultrasonic transmitter and ultrasonic receiver since the launch from time to time, single-chip selection of 8751, economic-to-us

50、e, and the chip has 4K of ROM, to facilitate programming. Circuit schematic diagram shown in Figure 2. Draw only the front range of the circuit wiring diagram, left and right in front of Ranging Ranging circuits and the

51、same circuit, it is omitted. </p><p>　　1,40 kHz ultrasonic pulse generated with the launch </p><p>　　Ranging system using the ultrasonic sensor of piezoelectric ceramic sensors UCM40, its operat

52、ing voltage of the pulse signal is 40kHz, which by the single-chip implementation of the following procedures to generate. </p><p>　　puzel: mov 14h, # 12h; ultrasonic firing continued 200ms </p><p

53、>　　here: cpl p1.0; output 40kHz square wave </p><p><b>　　nop; </b></p><p><b>　　nop; </b></p><p><b>　　nop; </b></p><p>　　djnz 14h,

54、 here; </p><p><b>　　ret </b></p><p>　　Ranging in front of single-chip termination circuit P1.0 input port, single chip implementation of the above procedure, the P1.0 port in a 40kHz

55、 pulse output signal, after amplification transistor T, the drive to launch the first ultrasonic UCM40T, issued 40kHz ultrasonic pulse, and the continued launch of 200ms. Ranging the right and the left side of the circui

56、t, respectively, then input port P1.1 and P1.2, the working principle and circuit in front of the same location. </p><p>　　2, reception and processing of ultrasonic </p><p>　　Used to receive the

57、 first launch of the first pair UCM40R, the ultrasonic pulse modulation signal into an alternating voltage, the op-amp amplification IC1A and after polarization IC1B to IC2. IC2 is locked loop with audio decoder chip LM5

58、67, internal voltage-controlled oscillator center frequency of f0 = 1/1.1R8C3, capacitor C4 determine their target bandwidth. R8-conditioning in the launch of the carrier frequency on the LM567 input signal is greater th

59、an 25mV, the output from the high jump 8 </p><p>　　Ranging in front of single-chip termination circuit output port INT0 interrupt the highest priority, right or left location of the output circuit with outpu

60、t gate IC3A access INT1 port single-chip, while single-chip P1.3 and P1. 4 received input IC3A, interrupted by the process to identify the source of inquiry to deal with, interrupt priority level for the first left right

61、 after. Part of the source code is as follows: </p><p>　　receive1: push psw </p><p><b>　　push acc </b></p><p>　　clr ex1; related external interrupt 1 </p><p&g

62、t;　　jnb p1.1, right; P1.1 pin to 0, ranging from right to interrupt service routine circuit </p><p>　　jnb p1.2, left; P1.2 pin to 0, to the left ranging circuit interrupt service routine </p><p>

63、;　　return: SETB EX1; open external interrupt 1 </p><p><b>　　pop acc </b></p><p><b>　　pop psw </b></p><p><b>　　reti </b></p><p>　　r

64、ight: ...?; right location entrance circuit interrupt service routine </p><p>　　Ajmp Return </p><p>　　left: ...; left Ranging entrance circuit interrupt service routine </p><p>　　A

65、jmp Return </p><p>　　3, the calculation of ultrasonic propagation time </p><p>　　When you start firing at the same time start the single-chip circuitry within the timer T0, the use of timer cou

66、nting function records the time and the launch of ultrasonic reflected wave received time. When you receive the ultrasonic reflected wave, the receiver circuit outputs a negative jump in the end of INT0 or INT1 interrupt

67、 request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read </p><p>　　RECEIVE0: PUSH PSW </p&g

68、t;<p><b>　　PUSH ACC </b></p><p>　　CLR EX0; related external interrupt 0 </p><p>　　MOV R7, TH0; read the time value </p><p>　　MOV R6, TL0 </p><p><

69、;b>　　CLR C </b></p><p>　　MOV A, R6 </p><p>　　SUBB A, # 0BBH; calculate the time difference </p><p>　　MOV 31H, A; storage results </p><p>　　MOV A, R7 </p>

70、<p>　　SUBB A, # 3CH </p><p>　　MOV 30H, A </p><p>　　SETB EX0; open external interrupt 0 </p><p><b>　　POP ACC </b></p><p><b>　　POP PSW </b&g

71、t;</p><p><b>　　RETI </b></p><p>　　For a flat target, a distance measurement consists of two phases: a coarse measurement and. a fine measurement:</p><p>　　Step 1: Transm

72、ission of one pulse train to produce a simple ultrasonic wave.</p><p>　　Step 2: Changing the gain of both echo amplifiers according to equation , until the echo is detected.</p><p>　　Step 3: Det

73、ection of the amplitudes and zero-crossing times of both echoes.</p><p>　　Step 4: Setting the gains of both echo amplifiers to normalize the output at, say 3 volts. Setting the period of the next pulses acco

74、rding to the : period of echoes. Setting the time window according to the data of step 2.</p><p>　　Step 5: Sending two pulse trains to produce an interfered wave. Testing the zero-crossing times and amplitud

75、es of the echoes. If phase inversion occurs in the echo, determine to otherwise calculate to by interpolation using the amplitudes near the trough. Derive t sub m1 and t sub m2 .</p><p>　　Step 6: Calculation

76、 of the distance y using equation .</p><p>　　D.Fourth, the ultrasonic ranging system software design </p><p>　　Software is divided into two parts, the main program and interrupt service routine,

77、 shown in Figure 3 (a) (b) (c) below. Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving control. </p><p>　　Interrupt service routines from time

78、 to time to complete three of the rotation direction of ultrasonic launch, the main external interrupt service subroutine to read the value of completion time, distance calculation, the results of the output and so on..&

79、lt;/p><p>　　System initialization after the start timer T1 starts counting from 0 to enter the main program to wait for the T1 overflow into the T1 interrupt service routine when the time is reached; T1 interru

80、pt service routine will start a new ultrasonic transmitting, the square wave will be generated in the P1.0 pin at the same time open the timer T0 timing, in order to avoid the diffraction of the direct wave, the delay 1m

81、s and then, after the INT0 interrupt Enable; the INT0 interrupt to allow open, if </p><p>　　E. CONCLUSIONS </p><p>　　Required measuring range of 30cm ~ 200cm objects inside the plane to do a num

82、ber of measurements found that the maximum error is 0.5cm, and good reproducibility. Single-chip design can be seen on the ultrasonic ranging system has a hardware structure is simple, reliable, small features such as me

83、asurement error. Therefore, it can be used not only for mobile robot can be used in other detection systems. </p><p>　　Thoughts: As for why the receiver do not have the transistor amplifier circuit, because