超聲波驅(qū)動(dòng)系統(tǒng)設(shè)計(jì)畢業(yè)論文外文翻譯

1、ultrasonic ranging system designpublication title: sensor review. bradford: 1993. vol. abstract：ultrasonic ranging technology has wide using worth in many fields，such as the industrial locale，vehicle navigation and sonar engineeringnow it has been used in level measurement，self-guided autonomous veh

2、icles, fieldwork robots automotive navigation，air and underwater target detection，identification，location and so onso there is an important practicing meaning to learn the ranging theory and ways deeply. to improve the precision of the ultrasonic ranging system in hand，satisfy the request of the eng

3、ineering personnel for the ranging precision，the bound and the usage，a portable ultrasonic ranging system based on the single chip processor was developedkeywords：ultrasound r，ranging system，single chip processor1.introductivewith the development of science and technology, the improvement of peoples

4、 standard of living, speeding up the development and construction of the city. urban drainage system have greatly developed their situation is constantly improving. however, due to historical reasons many unpredictable factors in the synthesis of her time, the city drainage system. in particular dra

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

6、t is very important to peoples lives. mobile robots designed to clear the drainage culvert and the automatic control system free sewage culvert clear guarantee robot, the robot is designed to clear the culvert sewage to the core. control system is the core component of the development of ultrasonic

7、range finder. therefore, it is very important to design a good ultrasonic range finder.2. a principle of ultrasonic distance measurement 2.1 the principle of piezoelectric ultrasonic generator piezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work. ultrasonic gener

8、ator, the internal structure as shown, it has two piezoelectric chip and a resonance plate. when its 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 reso

9、nance, 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 tra

10、ditional way to determine the moment of the echos arrival is based on thresholding the received signal with a fixed reference. the threshold is chosen well above the noise level, whereas the moment of arrival of an echo is defined as the first moment the echo signal surpasses that threshold. the int

11、ensity of an echo reflecting from an object strongly depends on the objects nature, size and distance from the sensor. further, the time interval from the echos starting point to the moment when it surpasses the threshold changes with the intensity of the echo. as a consequence, a considerable error

12、 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.2.2the principle of ultrasonic distan

13、ce measurement ultrasonic 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 cloc

14、k. 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 / 2 4. the ultrasonic ranging system software design software is divided into two parts, the main prog

15、ram and interrupt service routine. 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 ser

16、vice subroutine to read the value of completion time, distance calculation, the results of the output and so on. 5. 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

17、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 amplifi

18、er circuit, because the magnification well, integrated amplifier, but also with automatic gain control level, magnification to 76db, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequency.超聲波驅(qū)動(dòng)系統(tǒng)設(shè)計(jì)原文出處：傳感器文摘 布拉福德:1993年 超聲波電動(dòng)機(jī)(ultrasonic motor，簡(jiǎn)稱usm)是近年來(lái)發(fā)展起來(lái)的一種全新概念的驅(qū)動(dòng)裝置，

19、它利用壓電材料的逆壓電效應(yīng)(即電致伸縮效應(yīng))，把電能轉(zhuǎn)換為彈性體的超聲振動(dòng)，并通過(guò)摩擦傳動(dòng)的方式轉(zhuǎn)換成運(yùn)動(dòng)體的回轉(zhuǎn)或直線運(yùn)動(dòng)。這種新型電機(jī)一般工作于20khz以上的頻率，故稱為超聲波電動(dòng)機(jī)。它由定子(振動(dòng)體)和轉(zhuǎn)子(移動(dòng)體)兩部分組成，但電機(jī)中既沒(méi)有線圈也沒(méi)有永磁體，其定子由彈性體(elastic body)和壓電陶瓷(piezoelectric ceramic)構(gòu)成，轉(zhuǎn)子為一個(gè)金屬板。定子和轉(zhuǎn)子在壓力作用下緊密接觸，為了減少定、轉(zhuǎn)子之間相對(duì)運(yùn)動(dòng)產(chǎn)生的磨損，通常在二者之間(在轉(zhuǎn)子上)加一層摩擦材料。關(guān)鍵詞：超聲波，驅(qū)動(dòng)器，單片機(jī) 1、前言超聲電機(jī)是20世紀(jì)70年代發(fā)展起來(lái)的一種新型電機(jī)，以其不

20、同于傳統(tǒng)電磁電機(jī)的獨(dú)特優(yōu)勢(shì)近年來(lái)得到迅猛發(fā)展。它無(wú)磁極無(wú)繞組，不需要電磁之間的相互作用來(lái)轉(zhuǎn)換能量，而是利用壓電材料的逆壓電效應(yīng)實(shí)現(xiàn)機(jī)電能量轉(zhuǎn)換，將電能轉(zhuǎn)換為超聲頻率范圍內(nèi)的機(jī)械振動(dòng)( 頻率 20 k hz )，然后將定子的微觀變形通過(guò)摩擦耦合放大為動(dòng)子的宏觀運(yùn)動(dòng)。超聲電機(jī)具有運(yùn)行無(wú)噪音、大功率密度、不受磁場(chǎng)干擾、可斷電自鎖等特點(diǎn)，因此自問(wèn)世以來(lái)發(fā)展迅速。目前它已被成功應(yīng)用于航空航天、微機(jī)電力系統(tǒng)、精密定位裝置、汽車、照相機(jī)等領(lǐng)域，基于超聲電機(jī)眾多的優(yōu)良性能，未來(lái)必將獲得更加廣泛的應(yīng)用，極有可能取代部分微小型電磁電機(jī)。因此，超聲波電機(jī)驅(qū)動(dòng)控制技術(shù)成為微電機(jī)領(lǐng)域研究的一個(gè)熱點(diǎn)。通過(guò)對(duì)本課題的研究，

21、要求設(shè)計(jì)超聲波電機(jī)的驅(qū)動(dòng)電源，并達(dá)到兩路電源電壓的輸出，輸出電壓可調(diào)，調(diào)節(jié)幅度為100-150v,且其頻率可調(diào)，頻率調(diào)節(jié)范圍為100-15khz，占空比也可調(diào)。2、超聲波驅(qū)動(dòng)原理 2.1壓電式超聲波發(fā)生器原理壓電式超聲波發(fā)生器實(shí)際上是利用壓電晶體的諧振來(lái)工作的。超聲波發(fā)生器內(nèi)部結(jié)構(gòu)，它有兩個(gè)壓電晶片和一個(gè)共振板。當(dāng)它的兩極外加脈沖信號(hào)，其頻率等于壓電晶片的固有振蕩頻率時(shí)，壓電晶片將會(huì)發(fā)生共振，并帶動(dòng)共振板振動(dòng)，便產(chǎn)生超聲波。反之，如果兩電極間未外加電壓，當(dāng)共振板接收到超聲波 時(shí)，將壓迫壓電晶片作振動(dòng)，將機(jī)械能轉(zhuǎn)換為電信號(hào)，這時(shí)它就成為超聲波接收器了。2.2超聲波驅(qū)動(dòng)原理超聲波電源通常稱為超聲波發(fā)生源，超聲波發(fā)生器。它的作用是把電能轉(zhuǎn)換成與超聲波換能器相匹配的高頻交流電信號(hào)。從放大電路形式，可以采用線性放大電路和開關(guān)電源電路，大功率超聲波電源從轉(zhuǎn)換效率方面考慮一般采用開關(guān)電源的電路形式。線性電源也有它特有的應(yīng)用范圍，它的優(yōu)點(diǎn)是可以不