基于單片機的超聲測距儀設計外文翻譯

1、<p><b>　　中文2463字</b></p><p><b>　　中英文翻譯</b></p><p><b>　　</b></p><p><b>　　電氣工程學院</b></p><p><b>　　外文原文</b>

2、;</p><p>　　Ultrasonic ranging system design</p><p>　　Publication title: Sensor Review. Bradford: 1993. Vol. 13</p><p>　　ABSTRACT：Ultrasonic ranging technology has wide using worth i

3、n many fields，such as the industrial locale，vehicle navigation and sonar engineering．Now it has been used in level measurement，self-guided autonomous vehicles, fieldwork robots automotive navigation，air and underwater ta

4、rget detection，identification，location and so on．So there is an important practicing meaning to learn the ranging theory and ways deeply. To improve the precision of the ultrasonic ranging system in hand，satisfy the req&

5、lt;/p><p>　　Keywords：Ultrasound r，Ranging System，Single Chip Processor</p><p>　　1.Introductive</p><p>　　With the development of science and technology, the improvement of people's

6、standard of living, speeding up the development and construction of the city. urban drainage system have greatly developed their situation is constantly improving. However, due to historical reasons many unpredictable fa

7、ctors in the synthesis of her time, the city drainage system. In particular drainage system often lags behind urban construction. Therefore, there are often good building excavation has been building faci</p><

8、p>　　2. A principle of ultrasonic distance measurement </p><p>　　2.1 The principle of piezoelectric ultrasonic generator </p><p>　　Piezoelectric ultrasonic generator is the use of piezoelectri

9、c crystal resonators to work. Ultrasonic generator, the internal structure as shown, it has two piezoelectric chip and a resonance plate. When it's two plus pulse signal, the frequency equal to the intrinsic piezoele

10、ctric oscillation frequency chip, the chip will happen piezoelectric resonance, and promote the development of plate vibration resonance, ultrasound is generated. Conversely, if the two are not inter-electrode voltage, w

11、hen</p><p>　　The traditional way to determine the moment of the echo's arrival is based on thresholding the received signal with a fixed reference. The threshold is chosen well above the noise level, whe

12、reas the moment of arrival of an echo is defined as the first moment the echo signal surpasses that threshold. The intensity of an echo reflecting from an object strongly depends on the object's nature, size and dist

13、ance from the sensor. Further, the time interval from the echo's starting point to the moment </p><p>　　2.2The principle of ultrasonic distance measurement </p><p>　　Ultrasonic transmitter i

14、n a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread of ultrasound in the air, obstacles on his way to return immediately, the ultrasonic reflected wave received

15、by the receiver immediately stop the clock. Ultrasound in the air as the propagation velocity of 340m / s, according to the timer records the time t, we can calculate the distance between the launch distance barrier (s),

16、 that is: s = 340t / 2 </p><p>　　3.Ultrasonic Ranging System for the Second Circuit Design </p><p>　　System is characterized by single-chip microcomputer to control the use of ultrasonic transmi

17、tter and ultrasonic receiver since the launch from time to time, single-chip selection of 8751, economic-to-use, and the chip has 4K of ROM, to facilitate programming. Circuit schematic diagram shown in Figure 2. </p&

18、gt;<p>　　Figure 1 circuit principle diagram</p><p>　　3.1 40 kHz ultrasonic pulse generated with the launch </p><p>　　Ranging system using the ultrasonic sensor of piezoelectric ceramic se

19、nsors UCM40, its operating 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

20、200ms </p><p>　　here: cpl p1.0; output 40kHz square wave </p><p><b>　　nop; </b></p><p><b>　　nop; </b></p><p><b>　　nop; </b></p>

21、;<p>　　djnz 14h, 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, t

22、he P1.0 port in a 40kHz 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

23、left side of the circuit, respectively, then input port P1.1 and P1.2, the working principle and circuit in front of the same location. </p><p>　　3.2 Reception and processing of ultrasonic </p><p&

24、gt;　　Used to receive the 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 wit

25、h audio decoder chip LM567, 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 in

26、put signal is greater than 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 o

27、utput circuit with output 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

28、for the first left right 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 interru

29、pt 1 </p><p>　　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 rout

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

31、</p><p>　　right: ...; right location entrance circuit interrupt service routine </p><p>　　Ajmp Return </p><p>　　left: ...; left Ranging entrance circuit interrupt service routin

32、e </p><p>　　Ajmp Return </p><p>　　3.3 The calculation of ultrasonic propagation time </p><p>　　When you start firing at the same time start the single-chip circuitry within the tim

33、er T0, the use of timer counting 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 en

34、d of INT0 or INT1 interrupt request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read </p><p>　　RE

35、CEIVE0: PUSH PSW </p><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

36、</p><p><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&g

37、t;　　MOV A, R7 </p><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

38、>　　POP PSW </b></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><

39、;p>　　Step 1: Transmission 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>

40、<p>　　Step 3: Detection 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 o

41、f the next pulses according 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-cross

42、ing times and amplitudes 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>

43、;　　Step 6: Calculation of the distance y using equation .</p><p>　　4. The ultrasonic ranging system software design </p><p>　　Software is divided into two parts, the main program and interrupt s

44、ervice routine. 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 to time to complete t

45、hree 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. </p><p>　　

46、5. Conclusions </p><p>　　Required measuring range of 30cm ~ 200cm objects inside the plane to do a number of measurements found that the maximum error is 0.5cm, and good reproducibility. Single-chip design c

47、an be seen on the ultrasonic ranging system has a hardware structure is simple, reliable, small features such as measurement error. Therefore, it can be used not only for mobile robot can be used in other detection syste

48、ms. </p><p>　　Thoughts: As for why the receiver do not have the transistor amplifier circuit, because the magnification well, integrated amplifier, but also with automatic gain control level, magnification t

49、o 76dB, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequency</p><p>　　REFERENCES</p><p>　　1. Fox, J.D., Khuri-Yakub, B.T. and Kino, G.S., "High Frequency Aco

50、ustic Wave Measurement in Air", in Proceedings of IEEE 1983 Ultrasonic Symposium, October 31-2 November, 1983, Atlanta, GA, pp. 581-4.</p><p>　　2. Martin Abreu, J.M., Ceres, R. and Freire, T., "Ult

51、rasonic Ranging: Envelope Analysis Gives Improved Accuracy", Sensor Review, Vol. 12 No. 1, 1992, pp. 17-21.</p><p>　　3. Parrilla, M., Anaya, J.J. and Fritsch, C., "Digital Signal Processing Techniq

52、ues for High Accuracy Ultrasonic Range Measurements", IEEE Transactions: Instrumentation and Measurement, Vol. 40 No. 4, August 1991, pp. 759-63.</p><p>　　4. Canali, C., Cicco, G.D., Mortem, B., Prudenz

53、iati, M., and Taron, A., "A Temperature Compensated Ultrasonic Sensor Operating in Air for Distance and Proximity Measurement", IEEE Transaction on Industry Electronics, Vol. IE-29 No. 4, 1982, pp. 336-41.</

54、p><p>　　5. Martin, J.M., Ceres, R., Calderon, L and Freire, T., "Ultrasonic Ranging Gets Thermal Correction", Sensor Review, Vol. 9 No. 3, 1989, pp. 153-5.</p><p><b>　　外文譯文</b>

55、;</p><p>　　超聲波測距儀系統(tǒng)設計</p><p>　　摘要：超聲測距技術在工業(yè)現(xiàn)場、車輛導航、水聲工程等領域都具有廣泛的應用價值，目前已應用于物位測量、機器人自動導航以及空氣中與水下的目標探測、識別、定位等場合。因此，深入研究超聲的測距理論和方法具有重要的實踐意義。為了進一步提高測距的精確度，滿足工程人員對測量精度、測距量程和測距儀使用的要求，本文研制了一套基于單片機的便攜式超

56、聲測距系統(tǒng)。</p><p>　　關鍵詞：超聲波，測距儀，單片機 </p><p><b>　　1、前言</b></p><p>　　隨著科技的發(fā)展，人們生活水平的提高，城市發(fā)展建設加快，城市給排水系統(tǒng)也有較大發(fā)展，其狀況不斷改善。但是，由于歷史原因合成時間住的許多不可預見因素，城市給排水系統(tǒng)，特別是排水系統(tǒng)往往落后于城市建設。因此，經(jīng)常出現(xiàn)開

57、挖已經(jīng)建設好的建筑設施來改造排水系統(tǒng)的現(xiàn)象。城市污水給人們帶來了困擾，因此箱涵的排污疏通對大城市給排水系統(tǒng)污水處理，人們生活舒適顯得非常重要。而設計研制箱涵排水疏通移動機器人的自動控制系統(tǒng)，保證機器人在箱涵中自由排污疏通，是箱涵排污疏通機器人的設計研制的核心部分?？刂葡到y(tǒng)核心部分就是超聲波測距儀的研制。因此，設計好的超聲波測距儀就顯得非常重要了。</p><p>　　2、超聲波測距原理 </p>

58、<p>　　2.1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)，它有兩個壓電晶片和一個共振板。當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，當共振板接收到超聲波 時，將壓迫壓電晶片作振動，將機械能轉(zhuǎn)換為電信號，這時它就成為超聲波接收器

59、了。</p><p>　　測量脈沖到達時間的傳統(tǒng)方法是以擁有固定參數(shù)的接收信號開端為基礎的。這個界限恰恰選于噪音水平之上，然而脈沖到達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在不同時間超過界限卻在同一時間到達。強度較

60、強的脈沖會比強度較弱的脈沖超過界限的時間早點，因此我們會認為強度較強的脈沖屬于較近的物體。</p><p>　　2.2超聲波測距原理</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

61、距離(s)，即：s=340t/2</p><p><b>　　圖1 電路原理圖</b></p><p>　　3、超聲波測距系統(tǒng)的電路設計</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C51，經(jīng)濟易用，且片內(nèi)有4K的ROM，便于編程。電路原理圖如圖1所示。</p><

62、;p>　　3.1 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>　　here： cpl p1.0 ； 輸

63、出40kHz方波</p><p><b>　　nop ；</b></p><p><b>　　nop ；</b></p><p><b>　　nop ；</b></p><p>　　djnz 14h，here；</p><p><b>　　re

64、t</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。</p><p>　　3.2超聲波的接收與處理<

65、;/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)榈碗娖剑鳛橹袛嗾埱笮盘?，送至單片機處理.</p>&

66、lt;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><b>　　push acc</b>

67、</p><p>　　clr ex1； 關外部中斷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程序</p><p>　　return： SETB EX1；

68、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： ... ； 右測距電路

69、中斷服務程序入口</p><p>　　ajmp return</p><p>　　left： ... ； 左測距電路中斷服務程序入口</p><p>　　ajmp return</p><p>　　3.3計算超聲波傳播時間</p><p>　　在啟動發(fā)射電路的同

70、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。當收到超聲波反射波時，接收電路 輸出端產(chǎn)生一個負跳變，在INT0或INT1端產(chǎn)生一個中斷請求信號，單片機響應外部中斷請求，執(zhí)行外部中斷服務子程序，讀取時間差，計算距離。其部分源程序如下：</p><p>　　RECEIVE0： PUSH PSW</p><p><b>　　PUSH ACC&

71、lt;/b></p><p>　　CLR EX0 ； 關外部中斷0</p><p>　　MOV R7, TH0 ； 讀取時間值</p><p>　　MOV R6, TL0</p><p><b>　　CLR C</b></p><p><b>　

72、　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>　　SUBB A, #3CH</p><p

73、>　　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><b>　　RETI</b></p>

74、<p>　　對于一個平坦的目標，距離測量包括兩個階段:粗糙的測量和精細測量。</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撥被檢測到。</p><p>　　第三步：檢測兩種回波的振幅與過零時間。</p><p>　　第四步：設置回波放大器的所得來規(guī)

75、格輸出，假定是3伏。通過脈沖的周期設置下一個脈沖。根據(jù)第二部的數(shù)據(jù)設定時間窗。</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>　　4、超聲波測距系統(tǒng)的軟件設計</p><p>　　軟件分為兩部

76、分，主程序和中斷服務程序。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。定時中斷服務子程序完成三方向超聲波的輪流發(fā)射，外部中斷服務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><b>　　5、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，且重復性好?？梢娀?/p>

77、于單片機設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：至于為什么接收不用晶體管做放大電路呢，因為放大倍數(shù)搞不好，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><b>　　參考文獻</b&g

78、t;</p><p>　　1. Fox, J.D., Khuri-Yakub, B.T. and Kino, G.S., "High Frequency Acoustic Wave Measurement in Air", in Proceedings of IEEE 1983 Ultrasonic Symposium, October 31-2 November, 1983, Atlanta

79、, GA, pp. 581-4.</p><p>　　2. Martin Abreu, J.M., Ceres, R. and Freire, T., "Ultrasonic Ranging: Envelope Analysis Gives Improved Accuracy", Sensor Review, Vol. 12 No. 1, 1992, pp. 17-21.</p>

80、<p>　　3. Parrilla, M., Anaya, J.J. and Fritsch, C., "Digital Signal Processing Techniques for High Accuracy Ultrasonic Range Measurements", IEEE Transactions: Instrumentation and Measurement, Vol. 40 No.

81、4, August 1991, pp. 759-63.</p><p>　　4. Canali, C., Cicco, G.D., Mortem, B., Prudenziati, M., and Taron, A., "A Temperature Compensated Ultrasonic Sensor Operating in Air for Distance and Proximity Meas

82、urement", IEEE Transaction on Industry Electronics, Vol. IE-29 No. 4, 1982, pp. 336-41.</p><p>　　5. Martin, J.M., Ceres, R., Calderon, L and Freire, T., "Ultrasonic Ranging Gets Thermal Correction&