畢業(yè)設(shè)計(jì)基于單片機(jī)的超聲測(cè)距儀設(shè)計(jì)外文翻譯(標(biāo)準(zhǔn)格式)

1、外文原文Ultrasonic ranging system designPublication title: Sensor Review. Bradford: 1993. Vol. 13 ABSTRACT:Ultrasonic ranging technology has wide using worth in many fields,such as the industrial locale,vehicle navigation and sonar engineering.Now it has been used in level measurement,self-guided autono

2、mous vehicles, fieldwork robots automotive navigation,air and underwater target 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 request o

3、f the engineering personnel for the ranging precision,the bound and the usage,a portable ultrasonic ranging system based on the single chip processor was developed.Keywords:Ultrasound r,Ranging System,Single Chip Processor1.IntroductiveWith the development of science and technology, the improvement

4、of people's 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 factors in the synthesis of her time, the city drainage system. In

5、 particular drainage system often lags behind urban construction. Therefore, there are often good building excavation has been building facilities to upgrade the drainage system phenomenon. It brought to the city sewage, and it is clear to the city sewage and drainage culvert in the sewage treatment

6、 system. comfort is very important to people's lives. Mobile robots designed to clear the drainage culvert and the automatic control system Free sewage culvert clear guarantee robot, the robot is designed to clear the culvert sewage to the core. Control System is the core component of the develo

7、pment of ultrasonic range finder. Therefore, it is very important to design a good ultrasonic range finder.2. A principle of ultrasonic distance measurement2.1 The principle of piezoelectric ultrasonic generatorPiezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work

8、. Ultrasonic generator, the internal structure as shown, it has two piezoelectric chip and aresonance 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 development o

9、f plate vibration resonance, ultrasound is generated. Conversely, if the two are not inter-electrode voltage, when the board received ultrasonic resonance, it will be for vibration suppression of piezoelectric chip, the mechanical energy is converted to electrical signals, then it becomes the ultras

10、onic receiver.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, whereas the moment of arrival of an echo is defined as the first moment the echo signal surpass

11、es that threshold. 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 when it surpasses the threshold changes with the intensity of the echo. As

12、 a consequence, a considerable error ma y occur Even two echoes with different intensities arriving exactly at the same time will surpass the threshold at different moments. The stronger one will surpass the threshold earlier than the weaker, so it will be considered as belonging to a nearer object.

13、2.2The principle of ultrasonic distance measurementUltrasonic transmitter in 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 by th

14、e 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, that is: s = 340t / 23.Ultrasonic Ranging System for the Second Circuit DesignSystem

15、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-use, and the chip has 4K of ROM, to facilitate programming. Circuit schematic diagram shown in Figure 2.Fi

16、gure 1 circuit principle diagram 3.1 40 kHz ultrasonic pulse generated with the launchRanging system using the ultrasonic sensor of piezoelectric ceramic sensors UCM40, its operating voltage of the pulse signal is 40kHz, which by the single-chip implementation of the following procedures to generate

17、.puzel: mov 14h, # 12h; ultrasonic firing continued 200mshere: cpl p1.0; output 40kHz square wavenop;nop;nop;djnz 14h, here;retRanging 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 pulse output signal, after a

18、mplification 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 circuit, respectively, then input port P1.1 and P1.2, the working principle and circuit in front of the same locati

19、on.3.2 Reception and processing of ultrasonicUsed 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 with audio decoder chip LM567, internal vol

20、tage-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 than 25mV, the output from the high jump 8 feet into a low-level, as interrupt request signals to

21、the single-chip processing.Ranging in front of single-chip termination circuit output port INT0 interrupt the highest priority, right or left location of the output circuit with output gate IC3A access INT1 port single-chip, while single-chip P1.3 and P1. 4 received input IC3A, interrupted by the pr

22、ocess to identify the source of inquiry to deal with, interrupt priority level for the first left right after. Part of the source code is as follows:receive1: push pswpush accclr ex1; related external interrupt 1jnb p1.1, right; P1.1 pin to 0, ranging from right to interrupt service routine circuitj

23、nb p1.2, left; P1.2 pin to 0, to the left ranging circuit interrupt service routinereturn: SETB EX1; open external interrupt 1pop accpop pswretiright: .; right location entrance circuit interrupt service routineAjmp Returnleft: .; left Ranging entrance circuit interrupt service routineAjmp Return3.3

24、 The calculation of ultrasonic propagation timeWhen you start firing at the same time start the single-chip circuitry within the timer 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, th

25、e receiver circuit outputs a negative jump in the end 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 the time difference, calculating the distance . Some

26、of its source code is as follows:RECEIVE0: PUSH PSWPUSH ACCCLR EX0; related external interrupt 0MOV R7, TH0; read the time valueMOV R6, TL0CLR CMOV A, R6SUBB A, # 0BBH; calculate the time differenceMOV 31H, A; storage resultsMOV A, R7SUBB A, # 3CHMOV 30H, ASETB EX0; open external interrupt 0POP ACCP

27、OP PSWRETIFor a flat target, a distance measurement consists of two phases: a coarse measurement and. a fine measurement:Step 1: Transmission of one pulse train to produce a simple ultrasonic wave.Step 2: Changing the gain of both echo amplifiers according to equation , until the echo is detected.St

28、ep 3: Detection of the amplitudes and zero-crossing times of both echoes.Step 4: Setting the gains of both echo amplifiers to normalize the output at, say 3 volts.Setting the period of the next pulses according to the : period of echoes. Setting the time window according to the data of step 2.Step 5

29、: Sending two pulse trains to produce an interfered wave. Testing the zero-crossing 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 .Step 6: Calculation o

30、f the distance y using equation .4. The ultrasonic ranging system software designSoftware is divided into two parts, the main program and interrupt service routine. Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving control.Interrupt ser

31、vice routines from time 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.5. ConclusionsRequired measuring range of 30cm 200cm object

32、s inside the plane to do a number 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 measurement error. Therefore, it can be used not onl

33、y for mobile robot can be used in other detection systems.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 to 76dB, the center frequency is 38k to 40k, is ex

34、actly resonant ultrasonic sensors frequencyREFERENCES1. 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, GA, pp. 581-4.2. Martin Abreu, J.M., Ceres, R. and

35、 Freire, T., "Ultrasonic Ranging: Envelope Analysis Gives Improved Accuracy", Sensor Review, Vol. 12 No. 1, 1992, pp. 17-21.3. Parrilla, M., Anaya, J.J. and Fritsch, C., "Digital Signal Processing Techniques for High Accuracy Ultrasonic Range Measurements", IEEE Transactions: Ins

36、trumentation and Measurement, Vol. 40 No. 4, August 1991, pp. 759-63.4. Canali, C., Cicco, G.D., Mortem, B., Prudenziati, M., and Taron, A., "A Temperature Compensated Ultrasonic Sensor Operating in Air for Distance and Proximity Measurement", IEEE Transaction on Industry Electronics, Vol.

37、 IE-29 No. 4, 1982, pp. 336-41.5. 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.外文譯文超聲波測(cè)距儀系統(tǒng)設(shè)計(jì)原文出處:傳感器文摘布拉福德:1993年第13頁(yè)摘要:超聲測(cè)距技術(shù)在工業(yè)現(xiàn)場(chǎng)、車輛導(dǎo)航、水聲工程等領(lǐng)域都具有廣泛的應(yīng)用價(jià)值,目前已應(yīng)用于物位測(cè)量、機(jī)器人自動(dòng)導(dǎo)航以及空氣中與水下的目標(biāo)探測(cè)、識(shí)別、定

38、位等場(chǎng)合。因此,深入研究超聲的測(cè)距理論和方法具有重要的實(shí)踐意義。為了進(jìn)一步提高測(cè)距的精確度,滿足工程人員對(duì)測(cè)量精度、測(cè)距量程和測(cè)距儀使用的要求,本文研制了一套基于單片機(jī)的便攜式超聲測(cè)距系統(tǒng)。關(guān)鍵詞:超聲波,測(cè)距儀,單片機(jī)1、前言隨著科技的發(fā)展,人們生活水平的提高,城市發(fā)展建設(shè)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(shí)間住的許多不可預(yù)見(jiàn)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(shè)。因此,經(jīng)常出現(xiàn)開挖已經(jīng)建設(shè)好的建筑設(shè)施來(lái)改造排水系統(tǒng)的現(xiàn)象。城市污水給人們帶來(lái)了困擾,因此箱涵的排污疏通對(duì)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(shè)計(jì)研制箱涵排水

39、疏通移動(dòng)機(jī)器人的自動(dòng)控制系統(tǒng),保證機(jī)器人在箱涵中自由排污疏通,是箱涵排污疏通機(jī)器人的設(shè)計(jì)研制的核心部分?？刂葡到y(tǒng)核心部分就是超聲波測(cè)距儀的研制。因此,設(shè)計(jì)好的超聲波測(cè)距儀就顯得非常重要了。2、超聲波測(cè)距原理2.1壓電式超聲波發(fā)生器原理壓電式超聲波發(fā)生器實(shí)際上是利用壓電晶體的諧振來(lái)工作的。超聲波發(fā)生器內(nèi)部結(jié)構(gòu),它有兩個(gè)壓電晶片和一個(gè)共振板。當(dāng)它的兩極外加脈沖信號(hào),其頻率等于壓電晶片的固有振蕩頻率時(shí),壓電晶片將會(huì)發(fā)生共振,并帶動(dòng)共振板振動(dòng),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(shí),將壓迫壓電晶片作振動(dòng),將機(jī)械能轉(zhuǎn)換為電信號(hào),這時(shí)它就成為超聲波接收器了。測(cè)量脈沖到達(dá)時(shí)間的傳

40、統(tǒng)方法是以擁有固定參數(shù)的接收信號(hào)開端為基礎(chǔ)的。這個(gè)界限恰恰選于噪音水平之上,然而脈沖到達(dá)時(shí)間被定義為脈沖信號(hào)剛好超過(guò)界限的第一時(shí)刻。一個(gè)物體的脈沖強(qiáng)度很大程度上取決于這個(gè)物體的自然屬性尺寸還有它與傳感器的距離。進(jìn)一步說(shuō),從脈沖起始點(diǎn)到剛好超過(guò)界限之間的時(shí)間段隨著脈沖的強(qiáng)度而改變。結(jié)果,一種錯(cuò)誤便出現(xiàn)了兩個(gè)擁有不同強(qiáng)度的脈沖在不同時(shí)間超過(guò)界限卻在同一時(shí)間到達(dá)。強(qiáng)度較強(qiáng)的脈沖會(huì)比強(qiáng)度較弱的脈沖超過(guò)界限的時(shí)間早點(diǎn),因此我們會(huì)認(rèn)為強(qiáng)度較強(qiáng)的脈沖屬于較近的物體。2.2超聲波測(cè)距原理超聲波發(fā)射器向某一方向發(fā)射超聲波,在發(fā)射時(shí)刻的同時(shí)開始計(jì)時(shí),超聲波在空氣中傳播,途中碰到障礙物就立即返回來(lái),超聲波接收器收到

41、反射波就立即停止計(jì)時(shí)。超聲波在空氣中的傳播速度為340m/s,根據(jù)計(jì)時(shí)器記錄的時(shí)間t,就可以計(jì)算出發(fā)射點(diǎn)距障礙物的距離(s,即:s=340t/2 圖1 電路原理圖3、超聲波測(cè)距系統(tǒng)的電路設(shè)計(jì) 系統(tǒng)的特點(diǎn)是利用單片機(jī)控制超聲波的發(fā)射和對(duì)超聲波自發(fā)射至接收往返時(shí)間的 計(jì)時(shí)，單片機(jī)選用 C51，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 1 所示。 3.1 40kHz 脈沖的產(chǎn)生與超聲波發(fā)射 測(cè)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(hào)，這由單片機(jī)執(zhí)行下面程序來(lái)產(chǎn)生。 puzel： mov 14h, #12h；超聲波發(fā)射持續(xù)

42、 200ms here： cpl p1.0 ； nop ； nop ； nop ； djnz 14h，here； ret 前方測(cè)距電路的輸入端接單片機(jī) P1.0 端口，單片機(jī)執(zhí)行上面的程序后，在 P1.0 端 口輸出一個(gè) 40kHz 的脈沖信號(hào)，經(jīng)過(guò)三極管 T 放大，驅(qū)動(dòng)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(cè) 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(cè)距電路相同。 3.2 超聲波的接收與處理 接收頭采用與發(fā)射頭配對(duì)的 UCM40R，將超聲波調(diào)制脈沖變?yōu)榻蛔冸妷盒盘?hào)，經(jīng) 運(yùn)算放大器 IC1A 和 IC1B

43、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(hào)大于 25mV，輸出端 8 腳由高電平躍變?yōu)榈碗?平，作為中斷請(qǐng)求信號(hào)，送至單片機(jī)處理. 前方測(cè)距電路的輸出端接單片機(jī) INT0 端口，中斷優(yōu)先級(jí)最高，左、右測(cè)距電路的 輸出通過(guò)與門 IC3A 的輸出接單片機(jī) INT1 端口，同時(shí)單片機(jī) P1.3 和 P1.4 接到 IC3A 的 輸入端，中斷源的識(shí)別由程序查詢來(lái)處理，中斷優(yōu)先級(jí)為先右后左。部分源程序如下： receive1：push p

44、sw push acc 輸出 40kHz 方波 clr ex1； 關(guān)外部中斷 1 jnb p1.1,right；P1.1 引腳為 0,轉(zhuǎn)至右測(cè)距電路中斷服務(wù)程序 jnb p1.2,left；P1.2 引腳為 0,轉(zhuǎn)至左測(cè)距電路中斷服務(wù)程序 return： SETB EX1； pop pop reti right： . ； ajmp left： . ； ajmp return 3.3 計(jì)算超聲波傳播時(shí)間 在啟動(dòng)發(fā)射電路的同時(shí)啟動(dòng)單片機(jī)內(nèi)部的定時(shí)器 T0，利用定時(shí)器的計(jì)數(shù)功能記錄 超聲波發(fā)射的時(shí)間和收到反射波的時(shí)間。當(dāng)收到超聲波反射波時(shí)，接收電路 輸出端產(chǎn) 生一個(gè)負(fù)跳變，在 INT0 或 INT1

45、 端產(chǎn)生一個(gè)中斷請(qǐng)求信號(hào)，單片機(jī)響應(yīng)外部中斷請(qǐng)求， 執(zhí)行外部中斷服務(wù)子程序，讀取時(shí)間差，計(jì)算距離。其部分源程序如下： RECEIVE0： PUSH PSW PUSH ACC CLR EX0 ； MOV R7, TH0 ； MOV R6, TL0 CLR C MOV A, R6 SUBB A, #0BBH； MOV 31H, A ； MOV A, R7 SUBB A, #3CH MOV 30H, A SETB EX0 ； 開外部中斷 0 計(jì)算時(shí)間差 存儲(chǔ)結(jié)果 關(guān)外部中斷 0 讀取時(shí)間值 return 左測(cè)距電路中斷服務(wù)程序入口 右測(cè)距電路中斷服務(wù)程序入口 acc psw 開外部中斷 1 POP ACC POP PSW RETI 對(duì)于一個(gè)平坦的目標(biāo)，距離測(cè)量包括兩個(gè)階段:粗糙的測(cè)量和精細(xì)測(cè)量。 第一步：脈沖的傳送產(chǎn)生一種簡(jiǎn)單的超聲波。 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(cè)到。 第三步：檢測(cè)兩種回波的振幅與過(guò)零時(shí)間。 第四步：設(shè)置回波放大器的所