外文文献及翻译_Ultrasonic distance meter
三相电度表中英文对照外文翻译文献(精)
中英文对照外文翻译(文档含英文原文和中文翻译)always adopts mechanical tinplate to measure. There are some shortcomings that the measurement precision falls with machine abrasion, single time period setting and strong manpower [2]. In this paper, we propose a novel multi-rate three-phase watt-hour meter based on AT89LV52. This multi-rate three-phase watt-hour meter adoptsAD7752 for measurement. It has the characteristics which are time-sharing measurement, accurate measurement, LCD display, automatic meter reading, flexible time period setting, timely emendation, low cost and novel design. II. STRUCTURE AND WORKING PRINCIPLEThe novel multi-rate three-phase watt-hour meter proposed in this paper is based upon AT89LV52 singlechip [3]. AT89LV52 has the flash memorizer with 8k bytes, cryptographical program memorizer with third class, RAM with 256 bytes, 32 programmable I/O lines, three time/ counter with 16 bits and a two class halt with six vectors. The interface circuit adopts I2C bus unit which is a 8 bits singlechipwith good performance and suitable price. The system structure diagram is shown in figure 1.Figure 1. System structure diagramThe principle of this multi-rate watt-hour meter is reading in themulti-rate time segments using RS485 bus and noting in X25045 then take over correctional clock with RS485 bus and write in clock CMOS chip S3530A. Thethree-phase AC voltage and electric current pass through potentiometer and mutual inductance instrument respectively so as to produce small signal which is sent toAD7752 to complete measurement. The clock CMOS chip S3530A gives clockinformation per second in the course of automatic move and analyze this clock belongs to which period of time according to advance periods of time set in X25045 then save the electrical energy in RAM memorizeraccording to corresponding period of time. We write it to corresponding address ofX25045 when the electrical energy achieves one degree in order to make the multi-rate measurement come true. This watt-hour meter hasfunctions of clear LCD display, missing phase detection, burthen control, halt electricity check and storage, automatic meter reading and so on.III. THE DESIGH OF HARDWARE CIRCUITA． Electrical energy measurementThe three-phase electrical energy measurement is realized by the low consume CMOS chip AD7752 of ADI company. The inside of AD7752 adopts digital circuit besides ADC, filter and multiplication circuit which can eliminate noises effectively. The sampling course of voltage and electric current in three-phase AC power supply loop is shown in figure 2 in which IA stands for voltage sampling of A phase. The sampling circuits of B phase and C phase are similar to A phase. The power after integral is transformed to electrical pulse for output. The pulse of fan-out CF enters into interregnum INT0 of AT89LV52 through photoelectricity insulation 4N25. CPU measures the electrical energy [4]. We adjust the pulse number of CF by combining the state of S1 and S2. The connection of electrical energy and pulse is W = M C . In which, W is the electrical energy with the unit of kilowatt-hour, M is the total pulse number,C is the pulse number of ammeter. We choose C equals to 3000 that is to say every kilowatt-hour is 3000pulses.Figure 2. Circuit schematic diagramof watt-hour meterB． LCD displayThe LCD display [6] adopts HT1621 CMOS chip of HOLTEK Company toachieve twelve bits digital display. HT1621 is the LCD drivers with 128 segments (32×4) inner memorizer. The interior of HT1621 consists ofcontrol and time circuits, RAM, LCD drive and watch timer. It hasthe merits of small volume and low cost so that it is suit to watt-hour meter. We use serial interface which only has four lines between HT1621 and AT89LV52. The detailed connection is shown in figure 3. P20, P21, P22 and P23 of AT89LV52 connect to CS, RD, WR and DATA respectively with the use to refurbish the display of RAM. HT1621 drive CMOS chip has 48 nodes in which COM0, COM1, COM2, COM3 connect to the communal end and drive output of LCD and SG0, SG1, SG2, SG3 connect to drive output of every segment respectively. In addition, an adjustable resistance of 20kΩ is put between VDD and VLCD to adjust the display contrast of LCD. Experiment shows that the contrast is better with VDD=5V and VLCD=4V. C． Serial memorizerSerial memorizer adopts low power consumption chip X25045 of XICORcompany .It has three functions which are watchdog timer WTD, voltage supervision and serial memorizer E2PROM with 512 bytes. WTD can be set 200ms, 600ms and 1400ms time intervals. The software program is read into X25045. During the normal running of program, WTD receives the trigger signal in time intervals in order to ensure the normal running of program. X25045 will output a high potential through RESET line if WTD does not receive trigger signal in time intervals. The trigger watt-hour meter reset in order to prevent program flying away. As the serial memorizer chip, 512 bytes of X25045 are used to storage the watt-hour meter code, multi-rate periods of time, the apex electricity, smooth electricity, vale electricity and total electricity of last month and this month. Storage can be divided into two same areas. One is used as data storage. The other is used for backup. The number of storagecan be revised 100,000 times. Data can be stored for 100 years. It is connected withAT89LV52 by SPI agreement bus. The connection is shown in figure 3.D． Clock circuitThe clock circuit is completed by S3530A chip. It is a low powerconsumption clock chip that supports I2C Bus. It sets the clock and calendar according to the data received by CUP communicating with RS485. At the same time, it continues to walk time by its own oscillation. The crystaloscillator of 32.768 kHz is put between Xin and Xout of S3530A which is connected with CPU through latching. SDA foot and SCL foot connect to P1.6 and P1.7 ofAT89LV52 respectively. There are two interrupt alarming foots can be set as second output or minute output synchronizing pulse which supply interrupt signal toAT89LV52 with one second period. Single-chip system will readout the current time through I2C communication interface according to this signal and calculate the period of time that this moment belongs to so as to realize the electrical energy measurement in different periods of time [5]. This clock circuit has spare lithium battery. The powersupply VCC supply power in normal wiring and electrified for lithium battery of 3.6V. When there is power off, the system will automatically convert lithium battery to clock circuit for power supply. The clock will still running accurately even the power is off.Figure 3. Partial circuit figure of watt-hour meterE． RS485 CommunicationMAX485 chip can implement RS485 communication control ofmulti-rate watt-hour meter. MAX485 chip has RS485 communication protocol. It can take 128 hypogenous computers. Its transmission distance is greater than 1km and its transfer rate is up to 250kb per second. The watt-hour meter connects with the unit controller through the RS485 bus. Each unit has a cell controller can manage 128 multi-rate watt-hour meter. The cell controller connects to power management computer.Each watt-hour meter has one and only meter number with eight bits of hex. The electrician should write the user’s information and meter number and then import to the power management computer for initial installation so ad to complete the connection of user and management computer. Management computer sends setting of period of time and clock information with the manner of broadcast communication without address information. PC uploads information by the way of calling address. F． Lack Phase detection and relay controlIt can achieve relay control [7] with P27 of AT89LV52. P27 cancontrol relays using 4N25 photoelectricity isolator so as to complete powersupply and power control. Lack Phase detection gets the signal from fan-out of the relay and connects to 1 foot of photoelectricity isolator after passing a 75K resistance, the diode half-wave rectifier and capacitive filtering respectively. We detect the 4 foot of isolator to determine whether there is the lack of phase. If there is lack of phase, we detect again after 2 seconds overtime. We break off the power immediately if there is lack of power after the twice confirmation. In power protection circuit, it uses the INT1 interrupt foot of AT89LV52 to detect signal.When there is a sudden power off, INT1 jumps into a low voltage and the INT1 interrupt enters to the power protection program relying on the energy storage capacitor to save data. In the system, pulse output of AD7752, relay control port and the inputs of lack phase detection all use photoelectric isolator 4N25. It sends electrical signal by light coupling which can enhance the ability of anti-jamming. IV. THE DESIGN OF SOFTWAREA．The distribution of resourceThe software program includes main program, X25045 read and write program, RS485 serial communication program, interrupt serve program, timer handling program,HT1621 display control program, electrical energy measurement in different period of time and power down protection program, and system self-checking andanti-interference handling program. Interrupt resource distribution of system is: INT0 interrupt is used as AD7752 pulse measurement, INT1 as synchronization detecting, timer T0 as 100 ms timing, T1 as 1ms timing, and T2 as baud rate generator for serial communication program. RS485 asynchronous communication is set to receive interrupt and check information for sending.B． Module desighThe flow chart of main program is shown in figure 4. The watt-hourmeter should be able to initialize at each power up time. The initializing program includes setting working mode of timers, serial stomata and interrupts for AT89LV52,writing control word into X25045, S3530A and HT1621. This system sets three periods of time. The singlechip reads clock value from S3530A per second then analyze this clock belongs to which period of time according to advance periods of time set inX25045 then save the electrical energy in RAM memorizer according to corresponding period of time. We write it to corresponding address of X25045 when the electrical energy achieves one degree. The LCD display with 16 bits shows period of time and electrical energy information in turn. Figure 4. Flow chart of main program V. TESTING RESULTError measurement and running test have been made in Zibo Billion Electron Co., Ltd. The epigenous computer completes the setting of time management. There arethree-rate period of time. The first period of time is vale electricity from 00 point 00 minute to 06 point 30 minutes. The second period of time is apex electricity from 06 point 30 minutes to 22 point 30 minutes. The third period of time is smooth electricity from 22 point 30 minutes to 24 point 00 minute. The setting of rate period of time is sent to computer management system by electric power company according to national policy and saved in X25045. The apex electricity, smooth electricity, vale electricity and total electricity per month read saved in electrical energy meter and sent to epigenous computer through cell controller. The communication baud rate is 9600 bits per second. The checkout platform of 0.1 grade standard electronic power meter is used as standard meter and the multi-rate watt-hour meter is the tested meter. Billion Electron Company has carried out testing according to different load running. The measured data is shown in table 1 with the burthen of 30kW.TABLE I. COMPARE OF NORMAL METER AND TESTING METERThe testing result indicates that the error of this multi-ratewatt-hour meter is less than 1%, belongs to 1.0 grade. The return reading of electrical energy is precision and the emendation of time is timely and right. By testing, the method of decreasing errors for electricity metering can be obtained. Firstly, adjust the sampling resistance of AD7752 to accurate value. Secondly, the value of this resistance is needed less varying with temperature. Thirdly, during electricity metering progress, when mantissa portion of electricity is less than0.01, the remaining pulse should be accessed together, thus cumulative error caused by lack of 0.01degree energy loss could be avoided.VI. CONCLUSION AND EXPECTATIONThe multi-rate watt-hour meter achieves electrical energycomputation in different time according to different time setting. It adopts RS485 for serial communication and realizes automatic meter reading and real-time emendation. The results of production in Billion Electron Company showthat the multi-rate three-phase watt-hour meter proposed in this paper has the characteristics of novel design technique, accurate measurement, and flexible time period setting. Various technical indexes achieve the technique standard for national intelligent card watt-hour meter. Therefore, it has wide application. REFERENCES [1] Bu Zhengl iang, Yin Xianggen, Tu Guangyu. “Development of HV Watt-hour meter.” Automation of Electric Power Systems, 2006, 30(19): 89-93.[2] Kosukegawa M., Sakumoto Y. “Traceability system of electric energy standard and tendency in static watthour meter developmen t in Japan.” Sixth International Conference on Metering Apparatus and Tariffs for Electricity Supply, 1990,4: 259-263.[3] Xuehai Li. Applied tutorial of singlechip. Electronic industry publishing company, 2003.[4] Al-Khateeb Tarik, Blundel Martin. “An el ectronic meter for measuring the saving in electrical power.” The Ninth Arab International Conference on Solar Energy (AICSE-9), Kingdom of Bahrain, 2007,4 (209):328-333.[5] Liu Ying, Liu Qingyu. “Development of a self-calibration precision electricalmea suring meter.” Proceedings of the 1998 Conference Precision Electromagnetic Measurements, 1998,7:276.。
超声波测距外文文献加中文翻译毕业设计
附录A 英文原文ULTASONIC RANGING IN AIRG. E. Rudashevski and A. A. GorbatovOne of the most important problems in instrumentation technology is the remote,contactless measurement of distances in the order of 0.2 to 10 m in air.Such a problem occurs,for instance,when measuring the relativethre edimensional position of separate machine members or structural units.Interesting possibilities for its solution are opened up by utilizing ultrasonic vibrations as an information carrier.The physical properties of air,in which the measurements are made,permit vibrations to be employed at frequencies up to 500 kHz for distances up to 0.5 m between a member and the transducer,or up to 60 kHz when ranging on obstacles located at distances up to 10 m.The problem of measuring distances in air is somewhat different from other problems in the a -pplication of ultrasound.Although the possibility of using acoustic ranging for this purpose has been known for a long time,and at first glance appears very simple,nevertheless at the present time there are only a small number of developments using this method that are suitable for practical purposes.The main difficulty here is in providing a reliable acoustic three-dimensional contact with the test object during severe changes in the air's characteristic.Practically all acoustic arrangements presently known for checking distances use a method of measuring the propagation time for certain information samples from the radiator to the reflecting member and back.The unmodulated acoustic(ultrasonic)vibrations radiated by a transducer are not in themselves a source of information.In order to transmit some informational communication that can then be selected at the receiving end after reflection from the test member,the radiated vibrations must be modulated.In this case the ultrasonic vibrations are the carrier of the information which lies in the modulation signal,i.e.,they are the means for establishing the spatial contact between the measuring instrument and the object being measured.This conclusion,however,does not mean that the analysis and selection of parameters for the carrier vibrations is of minor importance.On the contrary,the frequency of the carrier vibrations is linked in a very close manner with the coding method for the informational communication,with the passband of the receiving and radiating elements in the apparatus,with the spatial characteristics of the ultrasonic communication channel,and with the measuring accuracy.Let us dwell on the questions of general importance for ultrasonic ranging in air,namely:on the choice ofa carrier frequency and the amount of acoustic power received.An analysis shows that with conical directivity diagrams for the radiator and receiver,and assuming thatthe distance between radiator and receiver is substantially smaller than the distance to the obstacle,theamount of acoustic power arriving at the receiving area Pr for the case of reflection from an ideal planesurface located at right angles to the acoustic axis of the transducer comes towhere Prad is the amount of acoustic power radiated,B is the absorption coefficient for a plane wave inthe medium,L is the distance between the electroacoustic transducer and the test me -mber,d is the diameterof the radiator(receiver),assuming they are equal,and c~is the angle of the directivity diagram for theelectroacoustic transducer in the radiator.Both in Eq.(1)and below,the absorption coefficient is dependent on the amplitude and not on theintensity as in some works[1],and therefore we think it necessary to stress this difference.In the various problems of sound ranging on the test members of machines and structures,therelationship between the signal attenuations due to the absorption of a planewave and due to thegeometrical properties of the sound beam are,as a rule,quite different.It must be pointed out that the choiceof the geometrical parameters for the beam in specific practical cases is dictated by the shape of thereflecting surface and its spatial distortion relative to some average position.Let us consider in more detail the relationship betweenthe geometric and the power parameters ofacoustic beams for the most common cases of ranging on plane and cylindrical structural members.It is well known that the directional characteristic W of a circular piston vibrating in an infinite baffle is afunction of the ratio of the piston's diameter to the wavelength d/λ as found from the following expression:(2)where Jl is a Bessel function of the first order and α is the angle between a normal to the piston and aline projected from the center of the piston to the point of observation(radiation).From Eq.(2)it is readily found that a t w o-t o-o n e reduction in the sensitivity of a radiator with respectto sound pressure will occur at the angle（3）For angles α≤20.Eq.(3)can be simplified to（4） where c is the velocity of sound in the medimaa and f is the frequency of the radiated vibrations.It follows from Eq.(4)that when radiating into air where c=330 m/s e c,the necessary diameter of the radiator for a spedfied angle of the directivity diagram at the 0.5 level of pressure taken with respect to the fdc 76.05.0≈αaxis can befound to be（5）where disincm,f is in kHz,and α is in degrees of angle.Curves are shown in Fig.1 plotted from Eq.(5)for six angles of a radiator's directivity diagram.The directivity diagrm needed for a radiator is dictated by the maximum distance to be measured and bythe spatial disposition of the test member relative to the other structural members.In order to avoid theincidence of signals reflected from adjacent members onto the acoustic receiver,it is necessary to provide asmall angle of divergence for the sound beam and,as far as possible,a small-diameter radiator.These tworequirements are mutually inconsistent since for a given radiation frequency a reduction of the beam'sdivergence angle requires an increased radiator diameter.In fact,the diameter of the"sonicated"spot is controlled by two variables,namely:the diameter of theradiator and the divergence angle of the sound beam.In the general case the minimum diameter ofthe"sonicated"spot Dmin on a plane surface normally disposed to the radiator's axis is given by（6）where L is the least distance to the test surface. The specified value of Dmin corresponds to a radiator with a diameter（7）As seen from Eqs.(,6)and(7),the minimum diameter of the"sonieated"spot at the maximum requireddistancecannot be less than two radiator diameters.Naturally,with shorter distances to the obstacle the sizeof the"sonicated" surface is less.Let us consider the case of sound ranging on a cylindrically shaped object of radius R.The problem is to measure the distance from the electroacoustic transducer to the side surface of the cylinderwith its various possible displacements along the X and Y axes.The necessary angleαof the radiator'sdirectivity diagram is given in this case by the expression（8） whereα is the value of the angle for the directivity diagram,Ymax is the maximum displacement of the cylinder's center from the acoustic axis,and Lmin is the minimum distance from the center of theelectroacoustic transducer to the reflecting surface measured along the straight line connecting the center ofthe m e m b e r with the center of the transducer.It is clear that when measuring distance,the"running"time of the information signal is controlled by thefd α1400≈fcL d 5.1=fcLD 6min =min maxarcsinL R y +≥αlength of the path in a direction normal to the cylinder's surface,or in other words,the measure distance isalways the shortest one.This statement is correct for all cases of specular reflection of the vibrations from thetest surface.The simultaneous solution of Eqs.(2)and(8)when W=0.5 leads to the following expression:(9) In the particular case where the sound ranging takes place in air having c=330 m/sec,and on theasstunption that L min <<R,the necessary d i a m e t e r of a unidirectional piston radiator d can be found fromthe fomula (10) where d is in cm and f is in kHz. Curves are shown in Fig.2 for determining the necessary diameter of the radiator as a function of theratio of the cylinder's radius to the maximum displacement from the axis for four radiation frequencies.Alsoshown in this figure is the directivity diagram angle as a function of R and Y rnax for four ratios of m i n i m u mdistance to radius.The ultrasonic absorption in air is the second factor in determining the resolution of ultrasonic rangingdevices and their range of action.The results of physical investigations concerning the measurement ofultrasonic vibrations air are given in[1-3].Up until now there has been no unambiguous explanation of thediscrepancy between the theoretical and expe -rimental absorption results for ultrasonic vibrations inair.Thus,for frequencies in the order of 50 to 60 kHz at a temperature of+25oC and a relative humidity of37%the energy absorption coefficient for a plane wave is about 2.5dB/m while the theoretical value is 0.3 dB/m.The absorption coefficient B as a function of frequency for a temperature of+25o Cand a humidity of37%according to the data in[2]can be described by Table 1.The absorption coefficient depends on the relative humidity.Thus,for frequencies in the order of 10 to20kHz the highest value of the absorption coefficient occurs at 20%humidity[3],and at 40%humidity theabsorption is reduced by about two to one.For frequencies in the order of 60 kHz the maximum absorptionoccurs at 30.7o humidity,dropping when it is increased to 98% or lowered to 10%by a factor of approximatelyfour to one.The air temperature also has an appreciable effect on the ultrasonic absorption[1].When thetemperature of the medium is increased from+10 to+30,the absorption for frequencies between 30 and 50kHz increases by about three to one.Taking all the factors noted above into account we arrive at the following approximate values for theabsorption coefficient:at a frequency of 60 kHz /3min =0.15 m -1 and~max=0.5-1;at a frequency of 200 ()maxmin 76.0y L R d +=λmax25fy R d ≈kHz/~min=0.6 m -1 and B max =2 m -1.（11）The values for the minimum~min and rnaxil-num~max"transmittance"coefficients were obtained in thea bsence of aerosols and rain.Their difference is the result of the possible variations in temperature over therange from -3 0 to+50~and in relative hmnidity over the range from 10 to 98%.The overall value ofthe"transmittance"is obtained by multiplying the values of g and 0 for given values of L,f,and d.L I T E R A T U R E C I T E DMoscow(1957).Moscow(1960).附录B 中文翻译在空气中超声测距G. E. Rudashevski and A. A. Gorbatov在仪器技术中远程是最重要的一个问题。
超声波测距系统外文文献翻译
=======大学本科生毕业设计外文文献及中文翻译文献题目： ULTRASONIC RANGING SYSTEM 文献出处： United States Patent译文题目：超声波测距系统学生：指导教师：专业班级：自动化11-4学号： 110601140416电气信息工程学院2014年5月1日超声波测距系统摘要超声波测距系统，是指选择性地激励一个变压器，使之产生换能器驱动信号。
超声换能器发射的超声波脉冲用于响应驱动信号然后接收到一个在超声波信号发出之后的回波信号。
分路开关接在变压器的绕组上，当超声波信号的传输在允许的近距离范围内达到一个稳定的等级，分路开关选择性的闭合来阻止蜂鸣器报警。
第1章发明背景像在宝丽来相机中应用的可用范围测试系统，它们都是准确而且可靠的，但都不适用于近距离测距，举个例子，2到3英寸的距离内就不适用，所以他们在9英寸甚至更远的距离测距是可靠的。
它们可以应用在很多的应用程序中，但不适用于可移动机器人领域内。
机器人通常必须通过门口只有两三英寸的间隙，如果当可移动机器人被操作于避障模式下通过狭小空间，可能机器人的规避路径过于狭窄，此外,规避动作应该使偏指定的路径距离最小化。
近距离测距不用于超声波系统的一个原因是，近距离输出脉冲输出太长以至于它重叠在回波脉冲上，即使输出脉冲缩短,输出脉冲仍然重叠回波脉冲，因为声音紧跟着输出脉冲。
备中产生的回波信号脉冲的范围为100毫伏，但设置传感器响应所必需的电路回声脉冲是大约150伏到300伏之间。
因此即使是最小的声波也会盖过回声信号。
事实上,dual-diode钳位电路用于将150伏降低到二极管的击穿电压，即0.7伏特。
但是这700毫伏足以盖过100毫伏的回波信号。
目前系统需要50毫秒将300伏特的峰值发射电压降到0.7伏特，且额外需要500到600毫秒的时间将它稳定在1毫伏范围。
第2章发明总结本发明可以提供一种改进的超声波测距系统。
本发明也可以提供一个改进的多通道超声波测距系统。
超声波测距外文翻译
超声波测距摘要：本演示处理了测量距离的超声波传感器在当前环境中的准确性。
作为一个测量传感器的选择SFR08型配备了允许寻址的I ²C 通信接口。
这一事实使得创建传感器阵列变得简单。
控制和可视化系统是基于PC PC。
NI USB 8451是作为通信卡使用的。
验证测量的目标是确定实际的传感器精度，特别是当测量较长的距离。
当评估传感器的精度时，不包括在所测量的数据的温度补偿。
关键词：超声波传感器，I ²C 通信接口，虚拟仪器1 1 简介简介超声波传感器通常用于自动化的任务来测量距离，位置变化，电平测量，如存在检测器或在特殊应用中，例如，当测量透明材料的纯度。
它们是基于测量超声波的传播时间的原则。
这一原则确保可靠的检测是独立的颜色渲染的对象或其表面的设计和类型。
它可以可靠地检测甚至液体，散装材料，透明物体，玻璃等材料。
他们使用的另一个参数是他们在侵略性的环境中使用，不是非常敏感的污垢和测量距离的可能性。
超声波传感器在许多机械设计中被制造。
对于实验室用途，用于发射器和接收器单独或在一个单一的简单的住房，对于工业用途，往往建造坚固的金属外壳。
有些类型允许您使用电位计或数字来调整灵敏度。
此外，输出可以在统一的版本中或直接以数字形式的模拟信号直接中。
就传感器来说，可以通过通信接口连接到PC ，它是可以设置所有传感器的工作范围和测量距离的详细参数。
2 2 超声测量超声测量超声对环境中的声音具有相似的传播特性。
这是机械振动的粒子环境。
超声波可以在气体、液体和固体中传播。
对于超声波通常被认为是一个频率高于20千赫的声音。
千赫的声音。
根据超声波的用途可以分为两类： 主动超声：当应用表现出物理或化学效应。
生成的输出达到更高的值。
超声波用于清洁，焊接，钻孔等。
被动超声；输出是在低得多（通常是小）值产生的对比度。
他的主要应用领域是测量距离，检测材料的缺陷和材料的厚度，测量液体和气体的流量，以及医疗保健的诊断。
超声测距外文-超声波距离和速度利用互相关方法对LPM信号测量
Ultrasonic distance and velocity measurement using a pair of LPM signals for cross-correlation method:Improvement of Doppler-shift compensation and examination of Doppler velocity estimation超声波距离和速度利用互相关方法对LPM信号测量：多普勒频移补偿和多普勒速度估计检测的改进数据来源Elsevier Journal Elsevier期刊刊物名Ultrasonics, 2012, Vol.52 (7), pp.873-879 超声波，2012，卷（7），pp.873-879 作者Shinnosuke Hirata, Minoru Kuribayashi Kurosawashinnosuke平田，稔栗林黑泽明单位机械工程与智能系统1，信息工程学院，电子通信，1-5-1 chofugaoka e4-329，，，布，东京182-8585大学，日本信息处理系，跨学科研究生科学与工程学院，东京工业大学，4259首席人事官g2-32，长津田，绿区，横滨，神奈川226-8502，日本AbstractReal-time distance measurement of a moving object with high accuracy and high resolution using an ultrasonic wave is difficult due to the influence of the Doppler effect or the limit of the calculation cost of signal processing. An over-sampling signal processing method using a pair of LPM signals has been proposed for ultrasonic distance and velocity measurement of moving objects with high accuracy and high resolution. The proposed method consists of cross correlation by single-bit signal processing, high-resolution Doppler velocity estimation with wide measurement range and low-calculation-cost Doppler-shift compensation. The over-sampling cross-correlation function is obtained from cross correlation by single-bit signal processing with low calculation cost. The Doppler velocity and distance of the object are determined from the peak interval and peak form in the cross-correlation function by the proposed method of Doppler velocity estimation and Doppler-shift compensation. In this paper, the proposed method of Doppler-shift compensation is improved. Accuracy of the determined distance was improved from approximately within ±140 μm in the previous method to approximately within ±10μm in computer simulations. Then, the proposed method of Doppler velocity estimation is evaluated. In computer simulations, accuracy of the determined Doppler velocity and摘要实时测量移动物体的高精度和高分辨率超声波存在的多普勒效应或信号处理的计算成本的限制的影响。
光电系毕业论文外文翻译半导体激光器适用于毕业论文外文翻译+
毕业设计（论文）英文翻译姓名学号０８１１１２２１２１所在学院理学院专业班级２００８级光信１班指导教师日期２０１２年４月２０日英文原文1.5 Experimental Setup Due to the many concepts and variations involved in performing the experimentsin this project and also because of their introductory nature Project 1 will very likelybe the most time consuming project in this kit. This project may require as much as 9hours to complete. We recommend that you perform the experiments in two or morelaboratory sessions. For example power and astigmatic distance characteristics maybe examined in the first session and the last two experiments frequency andamplitude characteristics may be performed in the second session. A Note of Caution All of the above comments refer to single-mode operation of the laser which is avery fragile device with respect to reflections and operating point. One must ensurethat before performing measurements the laser is indeed operating single-mode.This can be realized if a single broad fringe pattern is obtained or equivalently a goodsinusoidal output is obtained from the Michelson interferometer as the path imbalanceis scanned. If this is not the case the laser is probably operating multimode and itscurrent should be adjusted. If single-mode operation cannot be achieved by adjustingthe current then reflections may be driving the laser multimode in which case thesetup should be adjusted to minimize reflections. If still not operating single-modethe laser diode may have been damaged and may need to be replaced. Warning The lasers provided in this project kit emit invisible radiation that can damagethe human eye. It is essential that you avoid direct eye exposure to the laser beam.We recommend the use of protective eyewear designed for use at the laser wavelengthof 780 nm. Read the Safety sections in the Laser Diode Driver Operating Manual and in thelaser diode section of Component Handling and Assembly Appendix A beforeproceeding.1.5.1 Semiconductor Diode Laser Power Characteristics1. Assemble the laser mount assembly LMA-I and connect the laser to its powersupply. We will first collimate the light beam. Connect the laser beam to a videomonitor and image the laser beam on a white sheet of paper held about two to tencentimeters from the laser assembly. Slowly increase the drive current to the laser andobserve the spot on the white card. The threshold drive current rating of the laser issupplied with each laser. Increase the current to about 10-20 mA over the thresholdvalue. With the infrared imager or infrared sensor card observe the spot on the card andadjust the collimator lens position in the laser assembly LMA-I to obtain a bright spoton the card. Move the card to about 30 to 60 centimeters from the lens and adjust thelens position relative to the laser to obtain a spot where size does not vary stronglywith the position of the white card. When the spot size remains roughly constant asthe card is moved closer or further from the laser the output can be consideredcollimated. Alternatively the laser beam may be collimated by focusing it at adistance as far away as possible. Protect fellow co-workers from accidental exposureto the laser beam.2. Place an 818-SL detector on a post mount assembly M818 and adjust its positionso that its active area is in the center of the beam. There should be adequate opticalpower falling on the detector to get a strong signal. Connect the photodetector to thepower meter 815. Reduce the background lighting room lights so that the signalbeing detected is only from the laser. Reduce the drive current to a few milliamperesbelow threshold and again check to see that room light is not the dominantsignal atthe detector by blocking the laser light.3. Increase the current and record the output of the detector as a function of laser drivecurrent. You should obtain a curve similar to Figure 1.2. If desired the diodetemperature may also be varied to observe the effects of temperature on thresholdcurrent. When examining laser diode temperature characteristics the laser diodedriver should be operated in the constant current mode as a safeguard againstexcessive currents that damage the diode laser. Note that as the diode temperature isreduced the threshold decreases. Start all measurements with the diode current off toprevent damage to the laser by preventing drive currents too high above threshold.To prevent destruction of the laser do not exceed the stated maximum drive current ofthe laser.1.5.2 Astigmatic Distance Characteristics The laser diode astigmatic distance is determined as follows. A lens is used tofocus the laser beam at a convenient distance. A razor blade is then incrementallymoved across the beam to obtain data for total optical power passing the razor edge vs.the razor blade position. A plot of this data produces an integrated power profile of thelaser beam Figure 1.9a which through differentiation exposes the actual powerprofile Figure 1.9b which in turn permits determination of the beam diameter W.A beam diameter profile is obtained by measuring the beam diameter while varyingthe laser position. Figure 1.9c illustrates the two beam diameter profiles of interest:one for razor edge travel in the direction perpendicular to the laser diode junctionplane and the other for travel in the direction parallel to the junction plane. Theastigmatic distance for a laser diode is the displacement between the minima of thesetwo profiles. This method is known as the knife edge technique.1. Assemble the components shown in Figure 1.8 with the collimator lens LC in therotational stage assembly RSA-I placed roughly 1 centimeter away from the laser.The beam should travel along the optic axis of the lens. This is the same lens used incollimating the laser in the previous setup. The approximate placement of all thecomponents are shown in the figure. Make sure that the plane of the diode junctionxz plane in Figure 1.1 is parallel with the table surface.2. Due to the asymmetric divergence of the light the cross-section of the beamleaving the laser and further past the spherical lens is elliptical. The beam thus hastwo distinct focal points one in the plane parallel and the other in the planeperpendicular to the laser diode junction. There is a point between the two focalpoints where the beam cross-section is circular. With the infrared imager and a whitecard roughly determine the position where the beam cross-section is circular. Figure 1.9 – Procedure for finding astigmatic distance.3. Adjust the laser diode to lens distance such that the razor blades are located in thexy plane where the beam cross-section is circular.4. Move the laser diode away from the lens until minimum beam waist is reached atthe plane of razor blades. Now move the laser diode about 200 m further away fromthe lens.5. Move razor blade 1 in the x direction across the beam through the beam spreadθxand record the x position and detected intensity at each increment ≤100 mincrements. The expected output is shown in Figure 1.9. The derivative of this curveyields the intensity profile of the beam in the x direction from which the beamdiameter is determined.6. Repeat with razor blade 2 for θy in the y direction.7. Move the laser closer to the lens in increments ≤50 m through a total of at leastthan 500m. Repeat Steps 5 and 6 at each z increment recording the z position.8. Using the collected data determine the beam intensity profiles in the x and ydirections as a function of the lens position z. This is done by differentiating each dataset with respect to position. Then calculate the beam diameter and plot as a functionof z. The difference in z for the minimum in θx and θy isthe astigmatic distance of thelaser diode. Use of computer software especially in differentiating the data is highlyrecommended. If the laser junction is not parallel to the table surface then for eachmeasurement above you will obtain an admixture of the two beam divergences andthe measurement will become imprecise. If the laser is oriented at 45° to the surfaceof the table the astigmatic distance will be zero. Different laser structures will have different angular beam divergences and thusdifferent astigmatic distances. If you have access to several different laser types gainguided index guided it may be instructive to characterize their astigmatic distances.1.5.3 Frequency Characteristics of Diode Lasers In order to study frequency characteristics of a diode laser we will employ aMichelson interferometer to convert frequency variations into intensity variations. Anexperimental setup for examining frequency and also amplitude characteristics of alaser source is illustrated in Figure 1.10.1. In this experiment it is very possible that light may be coupled back into the laserthereby destabilizing it. An optical isolator therefore will be required to minimizefeedback into the laser. A simple isolator will be constructed using a polarizing beamsplitter cube and a quarterwave plate. We orient the quarterwave plate such that thelinearly polarized light from the polarizer is incident at 45° to the principal axes of thequarterwave plate so that light emerging from the quarterwave plate is circularlypolarized. Reflections change left-circular polarized light into right-circular or viceversa so that reflected light returning through the quarterwave plate will be linearlypolarized and 90° rotated with respect to the polarizer transmission axis. The polarizerthen greatly attenuates the return beam. In assembling the isolator make sure that the laser junction xz plane in Figure1.1 is parallel to the surface of the table the notch on the laser diode case pointsupward and the beam is collimated by the lens. The laser beam should be parallel tothe surface of the optical table. Set the polarizer and quarterwave λ/4 plate in place.Place a mirror after the λ/4 plate and rotate the λ/4 pl ate so that maximum rejectedsignal is obtained from the rejection port of the polarizing beam splitter cube asshown in Figure 1.11. When this signal is maximized the feedback to the laser shouldbe at a minimum.2. Construct the Michelson interferometer as shown in Figure 1.12. Place the beamsteering assembly BSA-II on the optical table and use the reflected beam from themirror to adjust the quarterwave plate orientation. Set the cube mount CM on theoptical breadboard place a double sided piece of adhesive tape on the mount and putthe nonpolarizing beam splitter cube 05BC16NP.6 on the adhesive tape. Next placethe other beam steering assembly BSA-I and the detector mountM818BB inlocation and adjust the mirrors so that the beams reflected from the two mirrorsoverlap at the detector. When long path length measurements are made the interferometer signal willdecrease or disappear if the laser coherence length is less than the two wayinterferometer path imbalance. If this is the case shorten the interferometer until thesignal reappears. If this does not work then check the laser for single-mode operationby looking for the fringe pattern on a card or by scanning the piezoelectric transducerblock PZBin BSA-II and monitoring the detector output which should be sinusoidalwith PZB scan distance. If the laser does not appear to be operatingsingle-moderealign the isolator and/or change the laser operating point by varying the bias current.Additionally to ensure single-mode operation the laser should be DC biased abovethreshold before applying AC modulation. Overdriving the laser can also force it intomultimode operation.3. The Michelson interferometer has the property that depending on the position of themirrors light may strongly couple back toward the laserinput port. In order to furtherreduce the feed-back slightly tilt the mirrors as illustrated in Figure 1.13. If stillunable to obtain single-mode operation replace the laser diode.4. Place a white card in front of the detector and observe the fringe pattern with theinfrared imager. Slightly adjust the mirrors to obtain the best fringe pattern. Try toobtain one broad fringe.5. Position the detector at the center of the fringe pattern so that it intercepts no morethan a portion of the centered peak.6. By applying a voltage to the piezoelectric transducer block attached to the mirrorpart PZB in one arm of the interferometer i.e. BSA-II maximize the outputintensity. The output should be stable over a time period of a minute or so. If it is notverify that all components are rigidly mounted. If they are then room air currents maybe destabilizing the setup. In this case place a box cardboard will do over the setupto prevent air currents from disturbing the interferometer setup.7. Place the interferometer in quadrature point of maximum sensitivity betweenmaximum and minimum outputs of the interferometer by varying the voltage on thePZB.8. The output signal of the interferometer due to frequency shifting of the laser isgiven by I∝φ 2π/c L ν where L is the difference in path length b etween thetwo arms of the interferometer and ν is the frequency sweep of the laser that isinduced by applying a current modulation. Remember that in a Michelsoninterferometer L is twice the physical difference in length between the arms sincelight traverses this length difference in both directions. L values of 3-20 cmrepresent convenient length differences with the larger L yielding higher outputsignals. Before we apply a current modulation to the laser note that the interferometeroutput signal I should be made larger than the detector or laser noise levels byproper choice of L and current modulation amplitude di. Also recall from Section1.3that when the diode current is modulated so is the laser intensity as well as itsfrequency. We can measure the laser intensity modulation by blocking one arm of theinterferometer. This eliminates interference and enables measurement of the intensitymodulation depth. We then subtract this value from the total interferometer output todetermine the true dI/di due to frequency modulation. Apply a low frequency smallcurrent modulation to the laser diode. Note that when the proper range is beingobserved 1 dv 10 5 mA 1 v diand 1 dI 0.2mA 1 I difor the amplitude change only.RecallingdI d（Δφ）2π Δv c dI ∝ΔL 10 5 mA 1 di di cΔi 2πΔLv diordI ΔL 2Kπ mA 1di λ10 -5where K is a detector response constant determined by varying L.9. With the interferometer and detection system properly adjusted vary the drivefrequency of the laser and obtain the frequency response of the laser Figure 1.4 or1.10a.You will need to record two sets of data: i the modulation depth of theinterferometer output as a function of frequency and ii the laser intensitymodulation depth. The difference of the two sets of collected data will provide anestimate of the actual dI/di due to frequency modulation. Also note that if the currentmodulation is sufficiently small and the path mismatch sufficiently large the laserintensity modulation may be negligible. You may need to actively keep theinterferometer in quadrature by adjusting the PZB voltage. Make any necessary function generator amplitude adjustments to keep thecurrent modulation depth of the laser constant as you vary the frequency. This isbecause the function generator/driver combination may not have a flat frequencyresponse. The effect of this is that the current modulation depth di is not constant andvaries with frequency. So to avoid unnecessary calculations monitor the current.。
超声波导盲仪及语音提示系统英文文献
毕业设计（论文）外文参考资料及译文译文题目：Ultrasonic distance meter超声波测距仪学生姓名：张宪旺学号： 1004104013 专业：自动化所在学院：机电工程学院指导教师：赵国树职称：讲师2014年01月08日超声测距系统设计原文出处：传感器文摘布拉福德:1993年第13页摘要：超声测距技术在工业现场、车辆导航、水声工程等领域都具有广泛的应用价值，目前已应用于物位测量、机器人自动导航以及空气中与水下的目标探测、识别、定位等场合。
因此，深入研究超声的测距理论和方法具有重要的实践意义。
为了进一步提高测距的精确度，满足工程人员对测量精度、测距量程和测距仪使用的要求，本文研制了一套基于单片机的便携式超声测距系统。
关键词：超声波，测距仪，单片机1、前言随着科技的发展，人们生活水平的提高，城市发展建设加快，城市给排水系统也有较大发展，其状况不断改善。
但是，由于历史原因合成时间住的许多不可预见因素，城市给排水系统，特别是排水系统往往落后于城市建设。
因此，经常出现开挖已经建设好的建筑设施来改造排水系统的现象。
城市污水给人们带来了困扰，因此箱涵的排污疏通对大城市给排水系统污水处理，人们生活舒适显得非常重要。
而设计研制箱涵排水疏通移动机器人的自动控制系统，保证机器人在箱涵中自由排污疏通，是箱涵排污疏通机器人的设计研制的核心部分。
控制系统核心部分就是超声波测距仪的研制。
因此，设计好的超声波测距仪就显得非常重要了。
2、超声波测距原理2.1压电式超声波发生器原理压电式超声波发生器实际上是利用压电晶体的谐振来工作的。
超声波发生器内部结构，它有两个压电晶片和一个共振板。
当它的两极外加脉冲信号，其频率等于压电晶片的固有振荡频率时，压电晶片将会发生共振，并带动共振板振动，便产生超声波。
反之，如果两电极间未外加电压，当共振板接收到超声波时，将压迫压电晶片作振动，将机械能转换为电信号，这时它就成为超声波接收器了。
外文文献翻译_压电传感器测定动脉脉搏波速度
Piezoelectric sensor determination of arterial pulse wave velocityArterial pulse wave velocity (APWV) is a measure of the elasticity (or stiffness) of peripheral arterial blood vessels. The pulse referred to here will be the pressure pulse as opposed to the flow pulse measured by ultrasound Doppler.The pressure pulse velocity varies over the range from about 12 m s?1 to15 m s?1 in stiff peripheral arteries, whereas in normal arteriesit has a velocity in the range of 7 to 9 m s?1.The aim of this project was the development of a fast and easy to use system for the determination of peripheral arterial pulse wave velocity. The principle of the PWV measurement is based on simultaneous measurement of two pulse waves at two different positions, such as the radial artery at the wrist and the brachial artery just above the elbow. By determining the pulse transit time between these points and the distance measured between the two locations, pulse wave velocity may then be calculated. The pressure pulse detection is done by using two piezoelectric sensors which generate a measurable voltage at the output contacts if they are mechanically deformed. The deformation produced voltage is first amplified and filtered and then digitalized with a data acquisition card. The analysis of the data obtained from the sensors includes a filtering process, the calculation of the PWV with three different methods— foot-to-foot, cross-correlation and peak-to-peak—and the determination of the arterial pulse rate.Extensive measurements with human test subjects were carried out to optimize the techniques of data acquisition and analysis. For example, it was found that the best procedure was to hold the sensors in place using elastic straps alone. The data analysis was upgraded with an additional software module, which deletes, in effect, outriders or invalid measurements. With the optimized system, a series involving eight test subjects ranging in age from 22 to 32 years was completed (all normotensive). The arterial pulse wave velocities determined covered a range from 6 m s?1to 12 m s?1, with an average standard deviation of less than 2.5 m s?1for individual results. These areslightly higher,but close to published APWV data. The results showedthat reproducible results can be obtained with the existing PWV acquirement and analysis system.The measurement of arterial pulse wave velocity (APWV) is one of the methods used to measure physiological changes in peripheral vascular disease. Others include pressure pulse contour, arterial elasticity, pulsatile flow, complex vascular impedance and cardiac work.There have been many investigations over the past 30 years or so to relate changes in age and progress of arterial disease, to vessel pathology and distensibility based on the propagation characteristics of the arterial pulse (Malindzak and Meredith 1970, McCormack 1981, Persson et al 2001, Ramsey 1995, Wilkinson 1998). They have only been partially successful from a clinical point of view, mainly due to the difficulty in controlling the effects of patient parameters (autonomic system, patient movement, etc).Early on, the methods of determining APWV involved direct invasive measurement of the pulse pressure at two points along anarterial segment and measuring the time taken for the pulse to travelthe length of the segment. Such investigations had to be limited to animals usually dogs.The sensor technique used in this work involves the piezoelectric effect in polyvinyllidene fluoride (PVDF), which produces an output voltage in response to mechanical pressure on the material.Three methods of APWV determination are used: foot-to-foot APWV; peak-to-peak APWV and cross-correlation APWV. The FFAPWV and CCAPWV methods are less sensitive to pressure wave reflections at bifurcations, etc in the arterial tree, than the PPAPWV method. Mean values and standard deviations were computed for all three methods and compared.‘Foot-to-foot’ APWV (FFAPWV). This is based on the velocity of the ‘foot’, or leading edge, of the pressure pulse wave. The ar rival times of the foot of the pulse wave at two positions along the artery are recorded. If Δt is the difference in arrival times and Δs the distance between the two recording positions (proximal and distal), the FFAPWV is simplyFFAPWV = Δs/Δt.‘Peak-to-peak’ APWV (PPAPWV). This is completely analogous to the FFAPWV except that the points of observation are the two (proximal and distal) peaks of the pulse wave andPPAPWV = Δs/Δt.Apparent pulse wave velocity (AAPWV). The pressure wave may be represented as aFourier series,P(t) = P0 +Pn sin(nωt + θn)Where P0 is the mean fluid pressure, n is the harmonic number, Pnis the amplitude of the nth harmonic and θn is the phase angle of the nth harmonic.The spatial rate of change of the phase for one harmonic based on two simultaneous pressure measurements separated by a distance _s along an artery, is related to the apparent arterial pulse wave velocity (AAPWV) by the following equation,AAPWVn = (Δs)n(f )(360o)/(θx1? θx2)Where AAPWV n is the apparent pulse wave velocity for the nth harmonic, f is the heart rate,θx1 is the phase angle for the proximal harmonic n and θx2 is the phase angle for the distal harmonic n.Cross-correlation PWV. If the arterial pulse at the proximal measurement position is represented by the pressure time series P(x1, t) and that at the distal position by P(x2, t) andthe cross-correlation coefficient is Φx1,x2(τ ), then Φwill have a maximum value at some time lag.The correlation function can be expressed asΦx1,x2(τ ) = (1/T )P(x1, t)P(x2, t) dt.The value of τ at which maximum correlation occurs represents the transit time (_t) of the pressure wave from position x1 to position x2 along the arterial segment. From the separation distance and transit time data the correlation arterial pulse wave velocity isCCAPWV = (x2 ? x1)/ Δt.In this work normal, young test subjects were used, and it has the primary objectives of optimizing the measurement procedures and establishing the statistical spread and mean values of the observed PWVs for a specific peripheral arterial segment. Based on this, it is planned to use the system in clinical trials involving patients with peripheral arterial disease (due to diabetes, hypertension, etc), pre-, during and post treatment (pharmaceutical or surgical).Analogue and digital circuitryAnalogue charge amplifier. Piezoelectric materials convert mechanical stress or strain into proportionate electrical energy, by producing a charge when subjected to mechanical stress. The charge is converted to a voltage by an operational amplifier connected as a current integrator, called a charge amplifier. The signal output of the amplifier is approximately ?30 mV. It is augmented by signal amplification.Analogue signal amplification . This is done by use of an inverting amplifier. Because a dc signal appears at the output of the chargeamplifier, dc offset removal is essential and is implemented in the inverting summingThe next phase of the analogue circuitry is a low pass filter to remove the 50 Hz noise interference.Digital controlled data acquisition and analysis. A dataacquisition board (DAQ) is required when the transducer signals need interfacing with a PC. The board contains 12 bit plus sign and a successive approximation and self-calibrating analogue-to-digital (ADC) converter. The ADC incurs a systematic error known as the quantization error. It is due to limited resolution and with the analogue input limit set at ?5 to +5 V, the quantization error of the A/D converter used here was calculated to be 0.122 mV.The data acquisition and analysis was done using Lab View—a powerful instrumentation and analysis programming language for PCs.Digital data acquisition program. The data acquisition circuit performs all the necessary operations for the data acquisition with Lab View. The functions of the circuit initialize the data acquisition and read the data from the acquisition card. These data are stored for later use in the data analysis part of the program.Lab View programs are called virtual instruments (VIs) because of their appearance and operations are analogous to measuring instruments.A VI that is called within another VI is called a sub-VI and is analogous to a subroutine in text-based languages.The data acquisition, analysis and presentation are comprised of three main procedures:(1) Data acquisition card to interface the hardware to the PC.(2) Data acquisition program to acquire and store data in a spreadsheet file.(3) Data analysis to carry out digital signal processing, calculate PWV and present results.PWV Calculation1. PWV calculation using peak detection. To calculate PWV using peaks, the location of the peaks must first be determined, so that the transit time of the wave between the peaks can be determined. It was found that the best method of peak detection is the derivative of the curve method. If the first derivative of a curve is zero, then an extreme value can exist—eithera peak or a turning point. It is necessary to take the second derivative at this point—if this is also zero, then an extreme value exists. The second VI used to determine the PWV is PWVcalc, using the time separation between the located peaks.2. PWV with pressure wave foot detection. The VI named PWV Foot determines the leading edge (foot) of the pressure wave at the upstream and downstream locations. The VI named PWVcalc is again used to compute the PWV from the time separation between the two leading edges (‘foot-to-foot’ APWV or FFAPWV).3. PWV with cross-correlation. The PWV determination with cross-correlation is done with the VI named CalcPWV. The VI is in two parts: a part for the initialization function and a part for the calculation of the CCAPWV.In all cases PWV values are assembled in an array and the mean value, standard deviation and variance are calculated.Sensor positioningSensor placement is critical to obtaining consistent measurements.A screw mechanism was first used to apply the sensors to the skin. But readings were very variable and so this technique was replaced by that in which the sensors are fixed to the skin by elastic strips. This led to better results.。
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毕业设计(论文)外文资料翻译系（院）：电子与电气工程学院专业：测控技术与仪器姓名：学号：外文出处：United States Patent5442592(用外文写)附件：1.外文资料翻译译文；2.外文原文。
指导教师评语：所选内容与课题相关，对课题设计参考具有一定价值；翻译具有一定难度，工作量适中；译文基本正确，语句通顺，但也存在部分错误。
总体评价：良签名：2012 年 3 月 15 日注：请将该封面与附件装订成册。
附件1：外文资料翻译译文超声波测距仪文件类型和数目：美国专利5442592摘要：提出了一种可以抵消温度的影响和湿度的变化的新型超声波测距仪，包括测量单元和参考资料。
在每一个单位，重复的一系列脉冲的产生，每有一个重复率，直接关系到各自之间的距离，发射机和接收机。
该脉冲序列提供给各自的计数器，计数器的产出的比率，是用来确定被测量的距离。
出版日期：1995年8月15日主审查员：罗保.伊恩j.一、背景发明本发明涉及到仪器的测量距离，最主要的是，这种仪器，其中两点之间传输超声波。
精密机床必须校准。
在过去，这已经利用机械设备来完成，如卡钳，微米尺等。
不过，使用这种装置并不利于本身的自动化技术发展。
据了解，两点之间的距离可以通过测量两点之间的行波传播时间的决定。
这样的一个波浪型是一种超声波，或声波。
当超声波在两点之间通过时，两点之间的距离可以由波的速度乘以测量得到的在分离的两点中波中转的时间。
因此，本发明提供仪器利用超声波来精确测量两点之间的距离对象。
当任意两点之间的介质是空气时，声音的速度取决于温度和空气的相对湿度。
因此，它是进一步的研究对象，本次的发明，提供的是独立于温度和湿度的变化的新型仪器。
二、综述发明这项距离测量仪器发明是根据上述的一些条件和额外的一些基础原则完成的，其中包括一个参考单位和测量单位。
参考和测量单位是相同的，每个包括一个超声波发射机和一个接收机。
间隔发射器和接收器的参考值是一个固定的参考距离，而间距之间的发射机和接收机的测量单位是有最小距离来衡量的。
在每一个单位，发射器和接收器耦合的一个反馈回路，它会导致发射器产生超声脉冲，这是由接收器和接收到一个电脉冲然后被反馈到发射机转换，从而使重复系列脉冲的结果。
重复率脉冲是成反比关系之间的距离发射器和接收器。
在每一个单位，脉冲提供一个反馈。
由于参考的距离是众所周知的声速，比例反产出是利用数学以确定所期望的距离来衡量。
由于这两方面都是相同的影响，温度和湿度的变化，采取的比例相同，由此产生的测量变得准确。
三、详细说明(一)超声波测距原理1、压电式超声波发生器原理压电式超声波发生器实际上是利用压电晶体的谐振来工作的。
超声波发生器内部结构如下所示，它有两个压电晶片和一个共振板。
当它的两极外加脉冲信号，其频率等于压电晶片的固有振荡频率时，压电晶片将会发生共振，并带动共振板振动，便产生超声波。
反之，如果两电极间未外加电压，当共振板接收到超声波时，将压迫压电晶片作振动，将机械能转换为电信号，这时它就成为超声波接收器了。
测量脉冲到达时间的传统方法是以拥有固定参数的接收信号开端为基础的。
这个界限恰恰选于噪音水平之上，然而脉冲到达时间被定义为脉冲信号刚好超过界限的第一时刻。
一个物体的脉冲强度很大程度上取决于这个物体的自然属性尺寸还有它与传感器的距离。
进一步说，从脉冲起始点到刚好超过界限之间的时间段随着脉冲的强度而改变。
结果，一种错误便出现了——两个拥有不同强度的脉冲在不同时间超过界限却在同一时间到达。
强度较强的脉冲会比强度较弱的脉冲超过界限的时间早点，因此我们会认为强度较强的脉冲属于较近的物体。
2、超声波测距原理超声波发射器向某一方向发射超声波，在发射时刻的同时开始计时，超声波在空气中传播，途中碰到障碍物就立即返回来，超声波接收器收到反射波就立即停止计时。
超声波在空气中的传播速度为340m/s，根据计时器记录的时间t，就可以计算出发射点距障碍物的距离(s)，即：s=340t/2二超声波测距系统的电路设计系统的特点是利用单片机控制超声波的发射和对超声波自发射至接收往返时间的计时，单片机选用8751，经济易用，且片内有4K的ROM，便于编程。
电路原理图如图所示。
其中只画出前方测距电路的接线图，左侧和右侧测距电路与前方测距电路相同，故省略之。
1、40kHz脉冲的产生与超声波发射测距系统中的超声波传感器采用UCM40的压电陶瓷传感器，它的工作电压是40kHz的脉冲信号，这由单片机执行下面程序来产生。
puzel： mov 14h, #12h；超声波发射持续200mshere： cpl p1.0 ；输出40kHz方波nop ；nop ；nop ；djnz 14h，here；ret前方测距电路的输入端接单片机P1.0端口，单片机执行上面的程序后，在P1.0端口输出一个40kHz的脉冲信号，经过三极管T放大，驱动超声波发射头UCM40T，发出40kHz的脉冲超声波，且持续发射200ms。
右侧和左侧测距电路的输入端分别接P1.1和P1.2端口，工作原理与前方测距电路相同。
2、超声波的接收与处理接收头采用与发射头配对的UCM40R，将超声波调制脉冲变为交变电压信号，经运算放大器IC1A和IC1B两极放大后加至IC2。
IC2是带有锁定环的音频译码集成块LM567，内部的压控振荡器的中心频率f0=1/1.1R8C3，电容C4决定其锁定带宽。
调节R8在发射的载频上，则LM567输入信号大于25mV，输出端8脚由高电平跃变为低电平，作为中断请求信号，送至单片机处理。
前方测距电路的输出端接单片机INT0端口，中断优先级最高，左、右测距电路的输出通过与门IC3A的输出接单片机INT1端口，同时单片机P1.3和P1.4接到IC3A的输入端，中断源的识别由程序查询来处理，中断优先级为先右后左。
部分源程序如下：receive1：push pswpush accclr ex1 ；关外部中断1jnb p1.1, right ； P1.1引脚为0,转至右测距电路中断服务程序 jnb p1.2, left ； P1.2引脚为0,转至左测距电路中断服务程序return： SETB EX1；开外部中断1pop accpop pswretiright： ... ；右测距电路中断服务程序入口ajmp returnleft： ... ；左测距电路中断服务程序入口ajmp return3、计算超声波传播时间在启动发射电路的同时启动单片机内部的定时器T0，利用定时器的计数功能记录超声波发射的时间和收到反射波的时间。
当收到超声波反射波时，接收电路输出端产生一个负跳变，在INT0或INT1端产生一个中断请求信号，单片机响应外部中断请求，执行外部中断服务子程序，读取时间差，计算距离。
其部分源程序如下：RECEIVE0： PUSH PSWPUSH ACCCLR EX0 ；关外部中断0MOV R7, TH0 ；读取时间值MOV R6, TL0CLR CMOV A, R6SUBB A, #0BBH；计算时间差MOV 31H, A ；存储结果MOV A, R7SUBB A, #3CHMOV 30H, ASETB EX0 ；开外部中断0POP ACCPOP PSWRETI对于一个平坦的目标，距离测量包括两个阶段:粗糙的测量和精细测量。
第一步：脉冲的传送产生一种简单的超声波。
第二步：根据公式改变回波放大器的获得量直到回拨被检测到。
第三步：检测两种回波的振幅与过零时间。
第四步：设置回波放大器的所得来规格输出，假定是3伏。
通过脉冲的周期设置下一个脉冲。
根据第二部的数据设定时间窗。
第五步：发射两串脉冲产生干扰波。
测量过零时间与回波的振幅。
如果逆向发生在回波中，决定要不通过在低气压插入振幅。
第六步：通过公式计算距离y。
四、超声波测距系统的软件设计软件分为两部分，主程序和中断服务程序，如图3（a）（b）(c) 所示。
主程序完成初始化工作、各路超声波发射和接收顺序的控制。
定时中断服务子程序完成三方向超声波的轮流发射，外部中断服务子程序主要完成时间值的读取、距离计算、结果的输出等工作。
系统初始化后就启动定时器T1从0开始计数，此时主程序进入等待，当到达定时时间时T1溢出进入T1中断服务子程序；在T1中断服务子程序中将启动一次新的超声波发射，此时将在P1.0引脚上开始产生kHz40的方波，同时开启定时器T0计时，为了避免直射波的绕射，需要延迟1ms后再开INT0中断允许；INT0中断允许打开后，若此时出现低电平则代表收到回波信号，将提出中断请求进入INT0中断服务子程序，在INT0中断服务子程序中将停止定时器T0计时，读取定时器T0时间值到相应的存储区，同时设置接收成功标志；主程序一旦检测到接收成功标志，将调用测温子程序，采集超声波测距时的环境温度，并换算出准确的声速，存储到RAM存储单元中；单片机再调用距离计算子程序进行计算，计算出传感器到目标物体之间的距离；此后主程序调用显示子程序进行显示；当一次发射、接收、显示的过程完成后，系统将延迟100ms重新让T1置初值，再次启动T1以溢出，进入下一次测距。
如果由于障碍物过远，超出量程，以致在T0溢出时尚未接收到回波，则显示“ERROR”重新回到主流程进入新一轮测试。
五、结论对所要求测量范围30cm~200cm内的平面物体做了多次测量发现，其最大误差为0.5cm，且重复性好。
可见基于单片机设计的超声波测距系统具有硬件结构简单、工作可靠、测量误差小等特点。
因此，它不仅可用于移动机器人，还可用在其它检测系统中。
思考：至于为什么接收不用晶体管做放大电路呢，因为放大倍数搞不好，CX20106集成放大电路，还带自动电平增益控制，放大倍数为76dB，中心频率是38k到40k，刚好是超声波传感器的谐振频率。
附件2：外文原文（复印件）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, 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 counters, and the ratio of the counter outputs is utilized to determine the distance being measured.Publication Date:08/15/1995Primary Examiner:Lobo, Ian J.A.BACKGROUND OF THE INVENTIONThis 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 as 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 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 provide 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,present invention to provide apparatus of the type described which is independent of temperature and humidity variations.B.SUMMARY OF THE INVENTIONThe foregoing 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 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 between 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 pulse 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 known, 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 DESCRIPTIONA.principle of ultrasonic distance measurement1, the principle of piezoelectric ultrasonic generatorPiezoelectric 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 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 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 ultrasonic 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 firstmoment the echo signal surpasses 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 a consequence, a considerable error may 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. 2, the 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 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), that is: s = 340t / 2B.Ultrasonic Ranging System for the Second Circuit DesignSystem 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. Draw only the front range of the circuit wiring diagram, left and right in front of Ranging Ranging circuits and the same circuit, it is omitted.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.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 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 principle and circuit in front of the same location.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 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 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 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 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 circuitjnb 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, 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, 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 service subroutine, read the time difference, calculating the distance . Some 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 ACCPOP 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.Step 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: 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 of the distance y using equation .D.Fourth, the ultrasonic ranging system software designSoftware is divided into two parts, the main program and interrupt service routine, 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.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, distance calculation, the results of the output and so on..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 interrupt 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 1ms and then, after the INT0 interrupt Enable; the INT0 interrupt to allow open, if thisoccurs when the low is representative of the received echo signal, the interrupt request to INT0 interrupt service routine, the INT0 interrupt service routine will stop the timer T0 timing, read the timevalue of T0 timer to the appropriate storage area.set to receive a sign of success; main program detects reception hallmarks of success, the temperature subroutine is called, collecting the ambient temperature when the ultrasonic ranging, and converted the accurate speed of sound stored in RAM storage unit; SCM calls the distance calculationsubroutine to calculate, calculate the distance between the sensor to the target object; since the main program calls the display subroutine to display; after completion of the first launch, receive, display, the system will delay 100ms re-T1 set initial value againstart T1 to overflow into the next ranging. If the obstacle is too far beyond the range that T0 overflow has not yet received echo "ERROR" is displayed back to the main flow into a new round of tests.E. CONCLUSIONSRequired 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 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 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。