超聲波測(cè)距儀外文資料翻譯

1、ultrasonic distance meterdocument type and number:united 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 series of pulses is generated, ea

2、ch 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 counters, and the ratio of the counter outputs is utilized to determine the distance being measured.a.background

3、 of the invention this invention relates to apparatus for the measurement of distance and, more particularly, to such apparatus which transmits ultrasonic waves between two points. precision machine tools must be calibrated. in the past, this has been accomplished utilizing mechanical devices such a

4、s calipers, micrometers, and the like. however, the use of such devices does not readily lend itself to automation techniques. it is known that 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

5、an ultrasonic, or acoustic, wave. when an ultrasonic wave travels between two points, the distance between the two points can be measured by multiplying the transit time of the wave by the wave velocity in the medium separating the two points. it is therefore an object of the present invention to pr

6、ovide apparatus utilizing ultrasonic waves to accurately measure the distance between two points. 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 further object of the,prese

7、nt invention to provide apparatus of the type described which is independent of temperature and humidity variations. b.summary of the invention the foregoing and additional objects are attained in accordance with the principles of this invention by providing distance measuring apparatus which includ

8、es a reference 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 reference unit is a fixed reference distance, whereas the spacing bet

9、ween the transmitter and receiver of the measuring unit is the distance to be measured. in each of the units, the transmitter and receiver are coupled by a feedback loop which causes the transmitter to generate an acoustic pulse which is received by the receiver and converted into an electrical puls

10、e which is then fed back to the transmitter, so that a repetitive series of pulses results. the repetition rate of the pulses is inversely related to the distance between the transmitter and the receiver. in each of the units, the pulses are provided to a counter. since the reference distance is kno

11、wn, the ratio of the counter outputs is utilized to determine the desired distance to be measured. since both counts are identically influenced by temperature and humidity variations, by taking the ratio of the counts, the resultant measurement becomes insensitive to such variations.c.detailed descr

12、iption a.principle of ultrasonic distance measurement 1, the principle of piezoelectric ultrasonic generator 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 piezoelectric chip and

13、 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 development of plate vibration resonance, ultrasound is generated. conversely, if the two are not inte

14、r-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 ultrasonic receiver. 2, the principle of ultrasonic distance measurement ultrasonic transmitter

15、 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 the receiver immediately stop the clock. ultrasound in the air as the propa

16、gation 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 / 2 b.ultrasonic ranging system for the second circuit design system is characterized by single-chip microcomputer to control the use of ul

17、trasonic 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. draw only the front range of the circuit wiring diagram, left and right

18、 in front of ranging ranging circuits and the same circuit, it is omitted. 1,40 khz ultrasonic pulse generated with the launch ranging system using the ultrasonic sensor of piezoelectric ceramic sensors ucm40, its operating voltage of the pulse signal is 40khz, which by the single-chip implementatio

19、n of the following procedures to generate. puzel: mov 14h, # 12h; ultrasonic firing continued 200ms here: cpl p1.0; output 40khz square wave nop; nop; nop; djnz 14h, here; ret ranging in front of single-chip termination circuit p1.0 input port, single chip implementation of the above procedure, the

20、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 left side of the circuit, respectively, then input port p1.1 and p1.2, the working

21、principle and circuit in front of the same location. 2, reception and processing of ultrasonic 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 locke

22、d loop with 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 input signal is greater than 25mv, the output from the high jump 8 feet

23、into a low-level, as interrupt request signals to 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 a

24、nd 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 after. part of the source code is as follows: receive1: push psw push acc clr ex1; related external interrupt 1 jnb p1.1, right; p1.1 pin to 0, r

25、anging from right to interrupt service routine circuit jnb p1.2, left; p1.2 pin to 0, to the left ranging circuit interrupt service routine return: setb ex1; open external interrupt 1 pop? acc pop? psw reti right: .?; right location entrance circuit interrupt service routine ? ajmp? return left: .;

26、left ranging entrance circuit interrupt service routine ? ajmp? return 3, the calculation of ultrasonic propagation time when 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 reflec

27、ted 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 request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt serv

28、ice subroutine, read the time difference, calculating the distance . some of its source code is as follows: receive0: push psw push acc clr ex0; related external interrupt 0 ? mov r7, th0; read the time value mov r6, tl0? clr c mov a, r6 subb a, # 0bbh; calculate the time difference mov 31h, a; stor

29、age results mov a, r7 subb a, # 3ch mov 30h, a? setb ex0; open external interrupt 0 pop acc? pop psw reti d.fourth, the ultrasonic ranging system software design software is divided into two parts, the main program and interrupt service routine, shown in figure 3 (a) (b) (c) below. completion of the

30、 work of the main program is initialized, each sequence of ultrasonic transmitting and receiving control. interrupt service 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

31、, distance calculation, the results of the output and so on. e. conclusions 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 can be seen on the ultrasonic ranging system

32、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 systems. thoughts: as for why the receiver do not have the transistor amplifier circuit, because the magnification well, cx20106

33、integrated amplifier, but also with automatic gain control level, magnification to 76db, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequency.超聲波測(cè)距儀摘要：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(cè)距儀，包括測(cè)量單元和參考資料。在每一個(gè)單位，重復(fù)的一系列脈沖的產(chǎn)生，每有一個(gè)重復(fù)率，直接關(guān)系到各自之間的距離，發(fā)射機(jī)和接收機(jī)。該脈沖序列提供給各自的計(jì)數(shù)器，計(jì)數(shù)器的產(chǎn)出的比率，是用

34、來(lái)確定被測(cè)量的距離。 一、背景發(fā)明 本發(fā)明涉及到儀器的測(cè)量距離，最主要的是，這種儀器，其中兩點(diǎn)之間傳輸超聲波。精密機(jī)床必須校準(zhǔn)。在過(guò)去，這已經(jīng)利用機(jī)械設(shè)備來(lái)完成，如卡鉗，微米尺等。不過(guò)，使用這種裝置并不利于本身的自動(dòng)化技術(shù)發(fā)展。據(jù)了解，兩點(diǎn)之間的距離可以通過(guò)測(cè)量?jī)牲c(diǎn)之間的行波傳播時(shí)間的決定。這樣的一個(gè)波浪型是一種超聲波，或聲波。當(dāng)超聲波在兩點(diǎn)之間通過(guò)時(shí)，兩點(diǎn)之間的距離可以由波的速度乘以測(cè)量得到的在分離的兩點(diǎn)中波中轉(zhuǎn)的時(shí)間。因此，本發(fā)明提供儀器利用超聲波來(lái)精確測(cè)量?jī)牲c(diǎn)之間的距離對(duì)象。 當(dāng)任意兩點(diǎn)之間的介質(zhì)是空氣時(shí)，聲音的速度取決于溫度和空氣的相對(duì)濕度。因此，它是進(jìn)一步的研究對(duì)象，本次的發(fā)明，提供

35、的是獨(dú)立于溫度和濕度的變化的新型儀器。 2、 綜述發(fā)明這項(xiàng)距離測(cè)量?jī)x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(gè)參考單位和測(cè)量單位。參考和測(cè)量單位是相同的，每個(gè)包括一個(gè)超聲波發(fā)射機(jī)和一個(gè)接收機(jī)。間隔發(fā)射器和接收器的參考值是一個(gè)固定的參考距離，而間距之間的發(fā)射機(jī)和接收機(jī)的測(cè)量單位是有最小距離來(lái)衡量的。在每一個(gè)單位，發(fā)射器和接收器耦合的一個(gè)反饋回路，它會(huì)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(gè)電脈沖然后被反饋到發(fā)射機(jī)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(gè)單位，脈沖提供一個(gè)反饋。由于參考的距離是眾所周知的聲速，比例反產(chǎn)出

36、是利用數(shù)學(xué)以確定所期望的距離來(lái)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(cè)量變得準(zhǔn)確。 三、詳細(xì)說(shuō)明一 超聲波測(cè)距原理 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)如下所示，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。 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

37、時(shí)刻的同時(shí)開(kāi)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/2二 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2所示。其中只畫(huà)出前方測(cè)距電路的接線圖，左側(cè)和右側(cè)測(cè)距電路與前方測(cè)距電路相同，故省略之。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

38、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)200mshere： cpl p1.0 ； 輸出40khz方波 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。2、超聲波的接收與處理 接收頭采用與發(fā)射頭配對(duì)的