超聲波測距儀外文資料翻譯

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距儀，包括測量單元和參考資料。在每一個單位，重復的一系列脈沖的產(chǎn)生，每有一個重復率，直接關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

34、來確定被測量的距離。 一、背景發(fā)明 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。在過去，這已經(jīng)利用機械設備來完成，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，或聲波。當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。 當任意兩點之間的介質是空氣時，聲音的速度取決于溫度和空氣的相對濕度。因此，它是進一步的研究對象，本次的發(fā)明，提供

35、的是獨立于溫度和濕度的變化的新型儀器。 2、 綜述發(fā)明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饋到發(fā)射機轉換，從而使重復系列脈沖的結果。重復率脈沖是成反比關系之間的距離發(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

36、是利用數(shù)學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)生的測量變得準確。 三、詳細說明一 超聲波測距原理 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)部結構如下所示，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，將機械能轉換為電信號，這時它就成為超聲波接收器了。 2、超聲波測距原理 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)射點距障礙物的距離(s)，即：s=340t/2二 超聲波測距系統(tǒng)的電路設計 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。其中只畫出前方測距電路的接線圖，左側和右側測距電路與前方測距電路相同，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，這由單片機執(zhí)行下面程序來產(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。右側和左側測 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。2、超聲波的接收與處理 接收頭采用與發(fā)射頭配對的