第一篇：外文翻譯

中原工學院畢業設計（論文）譯文

超聲測距系統設計

原文出處：傳感器文摘 布拉福德：1993年第13頁

摘要：超聲測距系統技校在工業場車輛導航水聲工程等領域都具有了廣泛的應用價值，目前已應用于物理測量，機器人自動導航以及空氣中與水下的目標探測、識別定位等場合，因此，深入研究超聲的探測理論和方法具有重要的實踐意義，為了進一步提高測量的精確度，滿足工程人員對測量精度測距量程和測距儀使用的要求，本文研制了一套基于單片機的使拱式超聲測距系統。關鍵詞：超聲波 測距儀 單片機

1、前言

隨著科技的發展，人們生活水平的提高，城市發展建設加快，城市給排水系統也有較大發展，其狀況不斷改善，但是，由于歷史原因合成時間性的許多不可預見因素，城市給排水系統，特別是排水系統往往落后于城市建設，因此，經常出現開挖已經建設好的建筑設施來改造排水系統的現象。城市污水給人們帶來的困擾，因此箱的排污疏通對大城市給排水系統污水理，人們生活舒適顯得非常重要。而設計研制箱涵排水疏通移動機器人的自動控制系統，保證機器人在箱涵中自由排污疏通，是箱涵排水系統疏通機器人的設計研制的核心部分，控制系統核心部分就是超聲波測儀的研制。因此，設計好的超聲波測距儀就顯得非常重要了。

1.1課題背景

隨著經濟的發展與汽車科學技術的進步，公路交通呈現出行駛高速化、車流密集化和駕駛員非職業化的趨勢。同時，隨著汽車工業的飛速發展，汽車的產量和保有量都在急劇增加。但公路發展、交通管理卻相對落后，導致了交通事故與日劇增，城市里尤其突出。智能交通系統ITS是目前世界上交通運輸科學技術的前沿技術，它在充分發揮現有基礎設施的潛力，提高運輸效率，保障交通安全，緩解交通賭塞，改善城市環境等方面的卓越效能，已得到各國政府的廣泛關注。中國政府也高度重視智能交通系統的研究開發與推廣應用。汽車防撞系統作為ITS 發展的一個基礎，它的成功與否對整個系統有著很大的作用。從傳統上說，汽車的安全可以分為兩個主要研究方向:一是主動式安全技術，即防止事故的發生，該種方式是目前汽車安全研究的最終目的;二是被動式安全技術，即事故發生后的乘員保護。目前汽車安全領域被動安全研究較多，主要從安全氣囊、ABS(防抱死系統)和懸架等方面著手，以保證駕乘人員的安全。從經濟性和安全性兩方面來說，中原工學院畢業設計（論文）譯文

這些被動安全措施是在事故發生時刻對車輛和人員進行保護，有很大的局限性，因而車輛的主動安全研究尤為重要，引出了本文研究的基于單片機的超聲波測距系統。這個系統是一種可向司機預先發出視聽語音信號的探測裝置。它安裝在汽車上，能探測企圖接近車身的行人、車輛或周圍障礙物;能向司機及乘員提前發出即將發生撞車危險的信號，促使司機采取應急措施來應付特殊險情，避免損失。

1.2 課題設計的意義

隨著現代社會工業化程的發展，汽車這一交通工具正為越來越多的人所用，但是隨之而來的問題也顯而易見，那就是隨著車輛的增多，交通事故的頻繁發生，由此導致的人員傷亡和財產損失數目驚人。對于公路交通事故的分析表明，80%以上的車禍事由于駕駛員反應不及所引起的，超過65%的車輛相撞屬于追尾相撞，其余則屬于側面相撞。奔馳汽車公司對各類交通事故的研究表明：若駕駛員能夠提早1S 意識到有事故危險并采取相應的正確措施，則絕大多數的交通事故都可以避免。因此，大力研究開發如汽車防撞裝置等主動式汽車輔助安全裝置，減少駕駛員的負擔和判斷錯誤，對于提高交通安全將起到重要的作用。顯然，此類產品的研究開發具有極大的實現意義和廣闊的應用前景。

1.3超聲波測距在汽車上應用的介紹

超聲波倒車測距儀(俗稱電子眼)是汽車倒車防撞安全輔助裝置，能以聲音或者更為直觀的數字形式動態顯示周圍障礙物的情況。其較早的產品是用蜂鳴器報警，蜂鳴聲越急，表示車輛離障礙物越近。后繼的產品可以顯示車后障礙物離車體的距離。其大多數產品探測范圍在0.4～1.5m，有的產品能達到0.35～2.5m，并有距離顯示、聲響報警、區域警示和方位指示，有些產品還具備開機自檢功能。目前市場上還出現了具有語音報警功能的產品。這些產品存在的主要問題是測量盲區大，報警滯后，未考慮汽車制動時的慣性因素，使駕駛者制動滯后，抗干擾能力不強，誤報也較多。汽車防撞雷達之所以能實現防撞報警功能，主要有超聲波這把無形尺子, 它測量最近障礙物的距離, 并告訴給車主。其實超聲測距原理簡單: 它發射超聲波并接收反射回波, 通過單片機計數器獲得兩者時間差t, 利用公式S=Ct/2計算距離, 其中S為汽車與障礙物之間的距離, C為聲波在介質中的傳播速度。

本文介紹的超聲測距系統共有2只超聲波換能器(俗稱探頭),分別布置在汽車的后左、后右2個位置上。能檢測前進和倒車方向障礙物距離, 通過后視鏡內置的

中原工學院畢業設計（論文）譯文

顯示單元顯示距離和方位, 發出一定的聲響, 起到提示和警戒的作用。系統采用一片STC89C52單片機對兩路超聲波信號進行循環采集。超聲波是指頻率高于20HHZ的機械波。為了以超聲波作為檢測手段，必須產生超生波和接收超聲波。完成這種功能的裝置就是超聲波傳感器，習慣上稱為超聲波換能器或超聲波探頭。超聲波傳感器有發送器和接收器，但一個超聲波傳感器也可具有發送和接收聲波的雙重作用。超聲波傳感器是利用壓電效應的原理將電能和超聲波相互轉化，即在發射超聲波的時候，將電能轉換，發射超聲波；而在收到回波的時候，則將超聲振動轉換成電信號。超聲波測距的原理一般采用渡越時間法。首先測出超聲波從發射到遇到障礙物返回所經歷的時間，再乘以超聲波的速度就得到二倍的聲源與障礙物之間的距離。測量距離的方法有很多種，短距離的可以用尺，遠距離的有激光測距等，超聲波測距適用于高精度的中長距離測量。因為超聲波在標準空氣中的傳播速度為331.45米/秒，由單片機負責計時，單片機使用12.0M晶振，所以此系統的測量精度理論上可以達到毫米級。由于超聲波指向性強，能量消耗緩慢，在介質中傳播距離遠，因而超聲波可以用于距離的測量。利用超聲波檢測距離，設計比較方便，計算處理也較簡單，并且在測量精度方面也能達到要求。超聲波發生器可以分為兩類：一類是用電氣方式產生超聲波，一類是用機械方式產生超聲波。本設計屬于近距離測量，可以采用常用的壓電式超聲波換能器來實現觸發單元。

利用超聲波測距的工作，就可以根據測量發射波與反射波之間的時間間隔，從而達到測量距離的作用。其主要有三種測距方法：

（1）相位檢測法，相位檢測法雖然精度高，但檢測范圍有限；

（2）聲波幅值檢測法，聲波幅值檢測法易受反射波的影響；

（3）渡越時間檢測法，渡越時間檢測法的工作方式簡單，直觀，在硬件控制和軟件設計上都非常容易實現。其原理為：檢測從發射傳感器發射超聲波，經氣體介質傳播到接收傳感器的時間，這個時間就是渡越時間。本設計的超聲波測距就是使用了渡越時間檢測法。在移動車輛中應用的超聲波傳感器，是利用超聲波在空氣中的定向傳播和固體反射特性（縱波），通過接收自身發射的超聲波反射信號，根據超聲波發出及回波接收的時間差和傳播速度，計算傳播距離，從而得到障礙物到車輛的距離。

中原工學院畢業設計（論文）譯文 超聲波測距原理

2.1 壓電式超聲波發生器原理

壓電式超聲波發生器實際上是利用壓電晶體的諧振來工作的。超聲波發生器內部結構，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，壓電晶片將會發生共振，并帶動共振板振動，便產生超聲波。反之，如果兩極板間未加電壓，當共振板接收到超聲波時，將壓迫壓電晶片做振動，將機械能轉換為電信號，這是它就成為超聲波接收器了。

測量脈沖到達時間的傳統方法是以擁有固定參數的接收信號開端為基礎的。這個信號恰恰選于噪音水平之上，然而脈沖到達時間被定義為脈沖信號剛好超過界限的第一時刻。一個物體的脈沖強度很大程度上取決于這個物體的自然屬性尺寸還有它與傳感器的距離。進一步說，從脈沖起始點到剛好超過界限之間的時間段隨著脈沖的強度而改變。結果，一種錯誤便出現了——兩個擁有不同強度的脈沖在不同時間超過界限卻在同一時刻到達。強度較強的脈沖會比強度較弱的脈沖超過界限的時間早點，因此我們會認為強度較強的脈沖屬于較近的物體。

2.2 超聲波測距原理

超聲波發射器向某一方向發射超聲波，在發射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，根據計時器記錄的時間t，就可以計算出發射點距離障礙物的距離(s)，即：s=340t/2

中原工學院畢業設計（論文）譯文

3、超聲波測距系統的電路設計

系統的特點是利用單片機控制超聲波的發射和超聲波自發射至接受往返時間的計時，單片機選用C51，經濟易用，且片內有4K的ROM，便于編程。電路的原理如圖1所示。

圖1 電路原理圖

中原工學院畢業設計（論文）譯文

3.1 40kHz脈沖的產生與超聲波發射

測距系統中的超聲波傳感器采用UCM40的壓電陶瓷，它的工作電壓是40kHz的脈沖信號，這由單片機執行下面的程序來產生。puzel：mov 14h，#12h

here： cp1.0；

nop；

nop；

nop；

djnz 14h，here；

Ret

前方測距電路的輸出端接單片機P1.0端口，單片機執行上面的程序后，在P1.0端口輸出一個40khz的脈沖信號，經過三極管T放大，驅動超聲波發射頭UCM40T，發出40khz的脈沖超聲波，且持續發射200ms。右側合作側測距電路的輸入端分別接P1.1和P1.2端口，工作原理和前方測距電路相同。

超聲波發射持續200ms 輸出40kHz方波

3.2 超聲波的接收與處理

接收頭采用與發射頭配對的UCM40R，將超聲波調制脈沖變為電壓信號，經運算放大器ic1a和ic1b兩級放大后加至IC2,。IC2是帶有鎖定環的音頻譯碼集成塊LM567，內部壓控振蕩器的中心頻率f0=1/1.1R8C3，電容C4決定其帶寬。調節R8在發射的載頻上，則LM567輸入信號大于25mv，輸出端8腳由5由高電平躍變為低電平，作為中斷請求信號，送至單片機處理。

前方測距電路的輸出端接至單片機INT0端口，中斷優先級最高，左、右測距電路的輸出通過與門IC3A的輸出接單片機的INT1端口，同時單片機P1.3和P1.4接到IC3A的輸入端，中斷源的識別由程序查詢來處理，中斷優先級為先右后左。部分源程序如下： receive1：push psw

push acc

clr ex1；關中斷源1

jnb p1.1，right;P1.1引腳為0，轉至右側距電路中斷服務程序

jnb p1.2,left;P1.2 引腳為0，轉至左測距中斷電路服務程序 returne：SETB EX1；

開外部中斷1

pop acc

中原工學院畢業設計（論文）譯文

pop psw

reti right：

...；

右測距電路中斷服務程序入口

ajmp return

left：

...；

左測距電路中斷服務程序入口

ajmp return

3.3 計算超聲波傳播時間

在啟動發射電路的同時啟動單片機內部的定時器T0，利用定時器的計數功能，記錄超聲波發射的時間和受到反射波的時間。當收到超聲波反射波時，接受電路輸出端產生一個負跳變，在INT0或INT1端產生一個中斷請求信號，單片機響應外部中斷請求，執行外部中斷服務子程序，讀取時間差，計算距離。其部分源程序如下：

RECEIVEO: PUSH PSW

PUSH ACC CLR EX0;

關外部中斷0 讀取時間值

MOV R7,TH0;MOV R6,TL0 CLR C MOV A,R6 SUBB A,#0BBH;MOV 31H,A;MOV A,R7 SUBB A,#3CH MOV 30H,A SETB EX0;POP ACC

POP PSW

RETI 對于一個平坦的目標，測量距離包括兩個階段：粗糙的測量和精細的測量。第一步：脈沖的傳送產生一種簡單的超聲波

第二步：根據公式改變回波放大器的獲得量直到回撥被檢測到。第三步：檢測兩種回波的振幅與過零時間。

計算時間值 存儲結果

開外部中斷0

中原工學院畢業設計（論文）譯文

第四步：設置回波放大器的所得規格輸出，假定是3v。通過脈沖的周期設置下一個脈沖。根據第二部的數據設定時間窗。

第五步：發射兩竄脈沖產生干擾波。測量過零時間與回波振幅。如果逆向發生在回波中，決定要不通過在低氣壓插入振幅。

第六步：通過公式計算距離y。

中原工學院畢業設計（論文）譯文

4、超聲波測距系統的軟件設計

軟件分為倆部分，主程序和中斷服務程序。主程序完成初始化工作、各路超聲波發射和接收順序的控制。定時中斷服務子程序完成三方向超聲波的輪流發射，外部中斷服務子程序主要完成時間值的讀取、距離計算、結果的輸出等工作。

中原工學院畢業設計（論文）譯文

5、結論

對所要求測量范圍30cm-200cm內的平面物體做了多次測量發現，其最大誤差為1.5cm，且重復性好。可見基于單片機設計的超聲波測距系統具有硬件結構簡單、工作可靠、測量誤差小等特點。因此，它不僅可用于移動機器人，還可以用在其他檢測系統中。

思考：至于為什么不用接收管做放大電路，因為放大倍數搞不好，集成放大電路，還帶自動電平增益控制，放大倍數為76db，中心頻率是38k到40k，剛好是超聲波傳感器的諧振頻率。

中原工學院畢業設計（論文）譯文

參考文獻

1.Fox，J.D.，Khuri-Yakub，B.T.and Kino，G.S.，“High Frequency Acoustic Wave Measurement in Air”，in Proceedings of IEEE 1983 Ultrasonic Symposium，October 31-2 November，1983，Atlanta，GA，pp.581-4.2.Martin Abreu，J.M.，Ceres,R.And Freire,T.,“Ultrasonic Ranging: Envelope Analysis Gives Improved Accuracy”,Sensor Review, Vol.12 No.1,1992,pp.17-21.3.Parrilla， M., Anaya,J.J and Fritsch C.,‖Digital Signal Processing Techniques for High Accuracy Ultrasonic Range Measurement:,IEEE Transactions: Instrumentation and Measurement.Vol.40 No.4, August 1991,pp.750-63.4.Canali, C., Cicco, G.D., Mortem, B., Prudenziati, M., and Taron, A., ―A Temperature Compensated Ultrasonic Sensor Operating in Air for Distance and Proxinmity Measurement‖, IEEE Trasaction on Industry Electronics, Vol, IE-29 No.4,1982, pp.336-41.5.Martin, J.M., Ceres, R., Calderon, L and Freire, T., ‖Ultrasonic Ranging Gets Themal Correction‖, Sensor Review, Vol, 9 No.3, 1989,pp.153-5.中原工學院畢業設計（論文）譯文

Ultrasonic ranging system design Publication title: Sensor Review.Bradford:1993.Vol.13 ABSTRACT: Ultrasonic ranging technology has wide using worth in many field, such as the industrial locale, vehicle navigation and sonar engineering.Now it has been used in level measurement, self-guided autonomous vehicles, fieldwork robots automotive navigation, air and underwater target detection, identification ,location and so on.So there is an important practicing meaning to learn the ranging theory and ways deeply.To improve the precision of the ultrasonic ranging system in hand, satisfy the request of the engineering personal for the precision,the bound and the usage, a portable ultrasonic ranging system based on the single chip processor was developed.Keywords: Ultrasound r, Ranging System, Single Chip Processor

1.Introductive With the development of science and technology, the improvement of people’s standard of living, speeding up the development and construction of the city.Urban drainage system have greatly developed their situation is constantly improving.However, due to historical reasons many unpredictable factors in the synthesis of her time, the city drainage system.In particular drainage system often lags behind urban construction.Therefore, there are often good building excavation has been building facilities to upgrade the drainage system phenomenon.It brought to the city sewage, and it is clear to the city sewage and drainage culvert in the sewage treatment system.Confort is very important to people’s lives.Mobile robots designed to clear the drainage culvert and the automatic control system Free sewage culvert clear guarantee robot, the robot is designed to clear the culvert sewage to the core.Control System is the core component of the development of ultrasonic range finder.Therefore, it is very important to design a good ultrasonic range finder.1.1 subject background

With the development of economy and car scientific and technological progress, highway traffic presents driving fast pace, traffic dense is changed and the driver not professional trend.At the same time, along with the rapid development of auto industry, automobile yield and quantities are increased dramatically.But road development，中原工學院畢業設計（論文）譯文

transportation management is relatively backward, leading to a large number of traffic accidents in some cities, especially prominent.Intelligent transportation system in the world, ITS transportation science and technology of advanced technology, ITS exerting existing infrastructure of potential, enhance the transport efficiency, safeguard traffic safety and ease traffic wager plug, improving urban environment aspects of outstanding performance, has received the governments of widespread concern.The Chinese government is also highly intelligent transportation system of the development and popularization applications.The automotive anti-collision system as ITS development of a base, ITS success to the whole system has a very significant role.Traditionally, auto safety said can be divided into two main research direction: first,it is active safety technology, including the prevention of accidents, the way is now automotive safety research ultimate purpose;second, it is passive safety technique, namely the occupant protection after the accident.Now automotive safety field passive safety more research, mainly from the airbag, ABS(antilock brakes)and suspension from the aspects such as to ensure safety of personnel rides.From the economic and safety two ways, these passive safety measures is the accident of vehicle and personnel moments protection, with great limitations, thus vehicle active safety research is particularly important, leads to a of this study is based on single chip ultrasonic ranging system.This system is a kind of can advance to the driver issued audio-visual speech signal detection devices.It is installed in cars that can detect trying to approach the body of a car pedestrians and vehicles or around obstacles, Can send to the driver and crew imminent danger ahead of the signal, prompting a crash drivers take emergency measures to cope with special danger, avoid the loss.1.2 question design significance

Along with the development of modern society industrialization process, car this traffic tools are used for more and more people, but any problem has obvious that along with the increase in vehicles, traffic accident, which led to the frequent occurrence of casualties and property losses number astonishing.For highway traffic accident analysis showed that more than 80% of the accident due to the driver reaction inferior things, caused more than 65% of vehicle collision, the rest belongs to tracing cauda collided belongs to the side collision.Mercedes-benz Automobile Company for all kinds of traffic accident research shows that: if the driver can early 1S are aware

中原工學院畢業設計（論文）譯文

that a accident risk and take the appropriate corrective measures, the overwhelming majority of traffic accidents can be avoided.Therefore, vigorously research and development as the automotive anti-collision device etc active car auxiliary safe device, reduce the burden and misjudgments drivers to improve the traffic safety will play an important role.Obviously, this kind of product research and development has great realize meaning and broad application prospects.1.3 Ultrasonic ranging in automotive applications introduced

Ultrasonic back-draft rangefinder(known as electron optics)automotive anti-collision reversing device, can safe adjunct to sound or more intuitive digital form the dynamic display of around obstacles.Its earlier products is to use buzzer alarm, hum more anxious, and says vehicles from obstructions closer.Subsequent product can display the car from the body after the obstacles distance.Most of its products detection range in 0.4 ~ 1.5 m, some product can achieve 0.35 ~ 2.5 m, and have distance display, sound alarm, area-warning and azimuth instructions, some products also has the boot self-checking function.Still appeared on the market at present with voice alarm function of products.These products are the main problem is big, alarm measuring blind area lags behind, without considering the automobile braking inertial factors and make drivers brake lag, the anti-interference ability is not strong, misstatement or more.The automotive anti-collision radar is able to realize impact-proof alarm functions, basically have ultrasonic this intangible ruler, it recently obstacles distance measurement, and told to the owner.Actually ultrasonic range-finding principle simple: it emit ultrasonic echo, and receive reflected by microcontroller counter obtain both lag using formula S = t, Ct / 2 calculating distances, including S for cars and obstacles, C for the distance between the sound wave propagation in the medium speed.This paper introduces the ultrasonic ranging system only have 2 ultrasonic transducer(known as probe)respectively, decorate in cars left and right after after 2 position.Capable of detecting forward and reverse direction obstacle distance, the rearview mirror built-in display element display distance and direction, issued must be sound, plays the role of hints and alert.System USES a STC89C52 SCM two way ultrasonic signal cyclicly acquisition.Ultrasonic refers to the 20HHZ wave frequency is over.In order to use the ultrasonic detection means, must generate as ultrasonic wave and receiving damnation.Complete the functions of the device is called the

中原工學院畢業設計（論文）譯文

ultrasonic sensor, habit, ultrasonic transducer or ultrasonic probe.Ultrasonic sensors have both transmitters and receivers, but a ultrasonic sensors can also has the sending and receiving the sound waves of the dual role.Ultrasonic sensors is using the principle of piezoelectric effect and ultrasonic energy conversion, be in namely emit ultrasonic, energy conversion, launch ultrasonic, And in the stockades, received echo ultrasonic vibration into electrical signal.Ultrasonic ranging principle generally USES the time method for the crossing.First measured ultrasonic from the launch to meet obstacles returns experience of time, again multiply ultrasonic speed of get twice the distance between the sound source and obstacles.Measuring distance a variety of ways, short can use ruler, long-range laser displacement etc, are suitable for high accuracy of ultrasonic ranging in long distance measurement.Because of ultrasound in standard air of propagation speed 331.45 meters per second, by single-chip microcomputer is responsible for timing, SCM use 12.0 M crystals, so the system of measurement precision theory can achieve mm level.Because of ultrasonic directivity strong, energy consumption is slow, in a medium transmission distance, thus ultrasonic can be used for distance measurement.Using ultrasonic detection distance, the design is more convenient, computing procese also relatively simple, and the measurement precision can also meet the requirements.Ultrasonic generator can be divided into two kinds: one kind is to use electrical means producing ultrasonic, one kind is with mechanical approach to producing ultrasonic.This design belongs to nearly distance measurement, can use commonly used the piezoelectric ultrasonic transducer to achieve trigger unit.Using ultrasonic ranging work, can according to measuring launch reflection wave wave and the time interval between the measured distance, so as to achieve the effect.It mainly have three ranging methods:

(1)phase assay, phase assays high precision, but detection though limited range，(2)sound amplitude assay, acoustic amplitude assay vulnerable reflection wave influence;

(3)ferrying more time assay, crossing the time assay way of working is simple, intuitive, in hardware control and software design are very easy to implement.Its principle is: from the launch emit ultrasonic detection sensor, the gas medium spread to receive sensor of time, this time is crossing the more time.This design is the use of ultrasonic ranging the crossing the time assay.In the mobile vehicles of the application 15

中原工學院畢業設計（論文）譯文

of ultrasonic sensor is the use of ultrasound in air of directional spread and solid reflective characteristics(p-wave)and by receiving their launch ultrasonic reflecting signal, according to the ultrasonic issued and echo receiving the Windows and propagation speed, calculate transmission distance, thus obtains the obstacles to vehicle distance.中原工學院畢業設計（論文）譯文

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 generator, the internal structure as shown, 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, 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 first moment 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 different intensities arriving exactly at the same tome 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.2.2 The principle of ultrasonic distance 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, obstracles on his way to return immediately, the ultrasonic reflected wave wave received by the reveiver immediately stop the clock.Ultrasonic 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

中原工學院畢業設計（論文）譯文

3.Ultrasonic Ranging System for the Second Circuit Design

System 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 1.Figure 1 circuit principle diagram

中原工學院畢業設計（論文）譯文

3.1 40 kHz ultrasonic pulse generated with the launch

Ranging system using the ultrasonic sensor of piezoelectric 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 200ms here:cpl pl.0;output 40 kHz 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 P1.0 port in a 40kHz pulze 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.3.2 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 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 port INT0 interrupt the highest priority, right or left location of the output circuit with output gete 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 code is as follows: receivel:

push psw

push ace

中原工學院畢業設計（論文）譯文

cir ex1: related external interrupt 1

jnb p1.1, right;P1.1 pin to 0, ranging from right to interrupt service rountine 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 rountine

Ajmp Return left:…;left Ranging entrance circuit interrupt service rountine

Ajmp Return

3.3 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 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 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 tome difference MOV 31H, A;storage results MOV A, R7 SUBB A,#3CH

中原工學院畢業設計（論文）譯文

MOV 30H,A SETB EX0;open external interrupt 0 POP ACC POP PAW RETI For 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 te amplitudes anf 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 in the echo,detemine to otherwise calculate to by interpolation using the amplitudes near the trough.Derive t sub ml and t sub m2.Step6: Calculation of the distance y using equation.中原工學院畢業設計（論文）譯文

4.The ultrasonic ranging system software design

Software is divided into two parts, the main program and interrupt service routine.Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving control.Tnterrupt service routines from time to complete three of the rotation direction of ultrasonic launch, the main external interrupt service subroutine to resd the value of completion time, distance calculation, the results of the output and so on.中原工學院畢業設計（論文）譯文

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 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, 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.中原工學院畢業設計（論文）譯文

REFERENCES 1.Fox,J.D.,Khuri-Yakub, B.T.and Kino, G.S., ‖High Frequency Acoustic Wave Measurement in Air‖, in Proceedings of IEEE 1983 Ultrasonic Symposium, October 31-2 November, 1983, Atlanta, GA, pp.581-4.2.Martin Abreu,J.M.,Ceres,R.and Freire, T.,‖Ultrasonic Ranging: Envelope Analysis Gives Improved Accuracy‖, Sensor Review, Vol.12No.1,1992, pp.17-21.3.Parrilla， M., Anaya,J.J and Fritsch C.,‖Digital Signal Processing Techniques for High Accuracy Ultrasonic Range Measurement:,IEEE Transactions: Instrumentation and Measurement.Vol.40 No.4, August 1991,pp.750-63.4.Canali, C., Cicco, G.D., Mortem, B., Prudenziati, M., and Taron, A., ―A Temperature Compensated Ultrasonic Sensor Operating in Air for Distance and Proxinmity Measurement‖, IEEE Trasaction on Industry Electronics, Vol, IE-29 No.4,1982, pp.336-41.5.Martin, J.M., Ceres, R., Calderon, L and Freire, T., ‖Ultrasonic Ranging Gets Themal Correction‖, Sensor Review, Vol, 9 No.3, 1989,pp.153-5.24

第二篇：外文翻譯

當今時代是一個自動化時代，交通燈控制等很多行業的設備都與計算機密切相關。因此，一個好的交通燈控制系統，將給道路擁擠，違章控制等方面給予技術革新。隨著大規模集成電路及計算機技術的迅速發展，以及人工智能在控制技術方面的廣泛運用，智能設備有了很大的發展，是現代科技發展的主流方向。本文介紹了一個智能交通的系統的設計。該智能交通燈控制系統可以實現的功能有：對某市區的四個主要交通路口進行控制：個路口有固定的工作周期，并且在道路擁擠時中控制中心能改變其周期：對路口違章的機動車能夠即時拍照，并提取車牌號。在世界范圍內，一個以微電子技術，計算機和通信技術為先導的，一信息技術和信息產業為中心的信息革命方興未艾。而計算機技術怎樣 與實際應用更有效的結合并有效的發揮其作用是科學界最熱門的話題，也是當今計算機應用中空前活躍的領域。本文主要從單片機的應用上來實現十字路口交通燈智能化的管理，用以控制過往車輛的正常運作。

研究交通的目的是為了優化運輸，人流以及貨流。由于道路使用者的不斷增加，現有資源和基礎設施有限，智能交通控制將成為一個非常重要的課題。但是，智能交通控制的應用還存在局限性。例如避免交通擁堵被認為是對環境和經濟都有利的，但改善交通流也可能導致需求增加。交通仿真有幾個不同的模型。在研究中，我們著重于微觀模型，該模型能模仿單獨車輛的行為，從而模仿動態的車輛組。

由于低效率的交通控制，汽車在城市交通中都經歷過長時間的行進。采用先進的傳感器和智能優化算法來優化交通燈控制系統，將會是非常有益的。優化交通燈開關，增加道路容量和流量，可以防止交通堵塞，交通信號燈控制是一個復雜的優化問題和幾種智能算法的融合，如模糊邏輯，進化算法，和聚類算法已經在使用，試圖解決這一問題，本文提出一種基于多代理聚類算法控制交通信號燈。

在我們的方法中，聚類算法與道路使用者的價值函數是用來確定每個交通燈的最優決策的，這項決定是基于所有道路使用者站在交通路口累積投票，通過估計每輛車的好處(或收益)來確定綠燈時間增益值與總時間是有差異的，它希望在它往返的時候等待，如果燈是紅色，或者燈是綠色。等待，直到車輛到達目的地，通過有聚類算法的基礎設施，最后經過監測車的監測。

我們對自己的聚類算法模型和其它使用綠燈模擬器的系統做了比較。綠燈模擬器是一個交通模擬器，監控交通流量統計，如平均等待時間，并測試不同的交通燈控制器。結果表明，在擁擠的交通條件下，聚類控制器性能優于其它所有測試的非自適應控制器，我們也測試理論上的平均等待時間，用以選擇車輛通過市區的道路，并表明，道路使用者采用合作學習的方法可避免交通瓶頸。

本文安排如下：第2部分敘述如何建立交通模型，預測交通情況和控制交通。第3部分是就相關問題得出結論。第4部分說明了現在正在進一步研究的事實，并介紹了我們的新思想。

The times is a automation times nowadays,traffic light waits for much the industey equipment to go hand in hand with the computer under the control of.Therefore,a good traffic light controls system,will give road aspect such as being crowded,controlling against rules to give a technical improvement.With the fact that the large-scale integrated circuit and the computer art promptness develop,as well as artificial intelligence broad in the field of control technique applies,intelligence equipment has had very big development,the main current being that modern science and technology develops direction.The main body of a book is designed having introduccd a intelligence traffic light systematically.The function being intelligence traffic light navar’s turn to be able to come true has：The crossing carries out supervisory control on four main traffic of some downtown area;Every crossing has the fixed duty period,charges centrefor being able to change it’s period and in depending on a road when being crowded;The motro vehicle breaking rules and regulations to the crossing is able to take a photo immediately,abstracts and the vehicle shop sign.Within world range ,one uses the microelectronics technology,the computer and the technology communicating by letter are a guide’s,centering on IT and IT industry information revolution is in the ascendant.But,how,computer art applies more effective union and there is an effect’s brought it’s effect into play with reality is the most popular topic of scientific community,is also that computer applications is hit by the unparalleled active field nowadays.The main body of a book is applied up mainly from slicing machine’s only realizing intellectualized administration of crossroads traffic light,use operation in controlling the vehicular traffic regularity.Transportation research has the goal to optimize transportation flow of people and goods.As the number of road users constantly increases, and resources provided by current infras-tructures are limited, intelligent control of traffic will become a very important issue in thefuture.However, some limitations to the usage of intelligent tra?c control exist.Avoidingtraffic jams for example is thought to be beneficial to both environment and economy, butimproved traffic-flow may also lead to an increase in demand [Levinson, 2003].There are several models for traffic simulation.In our research we focus on microscopicmodels that model the behavior of individual vehicles, and thereby can simulate dynam-ics of groups of vehicles.Research has shown that such models yield realistic behavior[Nagel and Schreckenberg, 1992, Wahle and Schreckenberg, 2001].Cars in urban traffic can experience long travel times due to inefficient traffic light con-trol.Optimal control of traffic lights using sophisticated sensors and intelligent optimizationalgorithms might therefore bevery beneficial.Optimization of traffic light switching increasesroad capacity and traffic flow, and can prevent tra?c congestions.Traffic light control is acomplex optimization problem and several intelligent algorithms, such as fuzzy logic, evo-lutionary algorithms, and reinforcement learning(RL)have already been used in attemptsto solve it.In this paper we describe a model-based, multi-agent reinforcement learningalgorithm for controlling traffic lights.In our approach, reinforcement learning [Sutton and Barto, 1998, Kaelbling et al., 1996]with road-user-based value functions [Wiering, 2000] is used to determine optimal decisionsfor each traffic light.The decision is based on a cumulative vote of all road users standingfor a traffic junction, where each car votes using its estimated advantage(or gain)of settingits light to green.The gain-value is the difference between the total time it expects to waitduring the rest of its trip if the light for which it is currently standing is red, and if it is green.The waiting time until cars arrive at their destination is estimated by monitoring cars flowingthrough the infrastructure and using reinforcement learning(RL)algorithms.We compare the performance of our model-based RL method to that of other controllersusing the Green Light District simulator(GLD).GLD is a traffic simulator that allows usto design arbitrary infrastructures and traffic patterns, monitor traffic flow statistics such asaverage waiting times, and test different traffic light controllers.The experimental resultsshow that in crowded traffic, the RL controllers outperform all other tested non-adaptivecontrollers.We also test the use of the learned average waiting times for choosing routes of cars through the city(co-learning), and show that by using co-learning road users can avoidbottlenecks.

第三篇：外文翻譯

設計一個位于十字路口的智能交通燈控制系統

摘要：本文模型使用模糊本體的交通燈控制域，并把它應用到控制孤立十字路口。本文最重要的目的之一是提出一個獨立的可重復使用的交通燈控制模塊。通過這種方式，增加軟件的獨立性和為其他的軟件開發活動如測試和維護，提供了便利。專家對本體論進行手動的開發和評估。此外，交通數據提取和分類路口使用的人工神經網絡的圖像處理算法。根據預定義的XML架構，這種信息轉化為XML實例映射到適合使用模糊推理引擎的模糊規則的模糊本體。把本系統的性能與其他類似的系統性能進行比較。比較結果顯示：在所有的交通條件下，在每個周期中，對每輛車它有低得多的平均延遲時間與其他的控制系統相比。

關鍵詞:模糊本體,智能代理,智能交通系統(ITS),交通信號燈控制(TLC),孤立的十字路口,圖像處理,人工神經網絡

1.引言

作為城市交通增加的結果,道路網絡的能力有限和發展交通工具和方法的技術方面，許多實體，關系，情況和規則已經進入交通燈控制域和轉化成為一個知識領域。這個領域的建模知識幫助交通代理和應用有效地管理關于實時條件下的交通。全面知識建模領域的一個最合適的方法是使用本體概念。“本體論是一個正式的、明確的一個共享的概念化的規范。以前的模型是基本的本體建設的基礎，為下列建立一個共享的語義豐富的知識域。除了本體作為概念化的形式主義的重要性，它有可能超過所代表的數據。這種能力將提高有關性能的決定和其他非智能系統的功能特點。在近年來，本體論上的研究正成為一個新的熱點話題在不同的活動，如人工智能，知識管理，語義網絡，電子商務和幾個其他應用領域。這些領域之一是智能交通系統。一些努力已制成這個通過展示和使用本體檢測交通領域擁塞，管理非城市道路氣象事件，駕駛阿德福—索里系統，共享和整合一個智能交通系統。本文的目的是介紹一個紅綠燈有效控制孤立交叉口這方面的知識重用的控制本體。這種新的辦法適用于智能代理使用知識決策模糊。該系統采用的圖像來自安裝了監控攝像機拍攝的路口。這些圖像處理利用圖像處理算法和神經網絡的方法，然后發送到一個智能代理。第2節中，我們將簡要地解釋了在這項工作中運用的技術包括seman-TIC網絡技術，智能代理技術和交通的回地面光控制方法。在第3節，新的系統架構是基于分層語義網絡架構。第4節介紹交通燈控制的模糊本體的建設。第五節從路口提取的圖像信息解釋。在第6節，智能系統的運作被完整描述，最后在第7節對所提出的方法進行評估，對結論進行闡述。

2.背景

本節說明在這項工作中的應用技術包括語義網絡技術，特別本體和模糊本體。此外，國家的交通燈控制的藝術方法是簡要介紹。2.1.語義網絡技術

語義網絡被定義為當前Wed的延伸，這些網站的信息都給出明確的含義;使電腦與人更好的合作。有幾層語義Web的建議源自伯納斯滯后階段。在此類別中的所有規則如表1所示。圖.4顯示輸出模式的示意圖。本次評選有助于智能系統，以確定下一步的階段測序。

另一種模糊的規則類別涉及估計優化周期時間。這些規則的模糊變量是天氣條件，時間，每天平均車輛擁堵情況。出于這個原因，60個模糊規則被定義了。從氣象研究所取得氣象條件。日期和時間也是在交通專家的知識的基礎上以模糊變量形式預先定義的。圖5顯示日期，時間和周期時間的隸屬函數。當天的參數是在日歷基礎上基于假期和正常的一天與周期時間量的關系預定義的。例如，假期期間的周期時間是較平日少。因此，平日的隸屬度比假期多。

例如一個階段選型的模糊規則如下所述：“如果一個路口的類型是四的方式，平均車輛擁堵低，平均行人擁堵是中等，然后相類型是簡單的兩階段”。此外，為周期時間估計的模糊規則表示如下：“如果天氣條件是晴天，時間是早晨，天是正常的，平均車輛擁堵是低，則周期時間短”。在此類別中的所有規則都列在附錄A。

在此步驟結束時，應該對交通燈邏輯控制的項目的有效性進行評估。此功能是使用專家的意見。評價過程的主要目的是顯示發展的本體和其相關的軟件環境的用處。雖然所有的信息，尤其是交通燈控制規則已提取國際標準和科學交通文學，專家的知識優勢是他們最后的正確性驗證標準。所有模糊規則，包括優化周期時間和相位類型的規則，在這個過程中，準備以調查問卷形式和展現給一些專家包括從德黑蘭警察局交通上校和兩名來自德黑蘭的交通組織工程師。由于德爾菲專家的意見，約有84％的淘汰型規則和優化周期時間的87％被接受。此外，所有交通邏輯控制的元素包括概念，關系，屬性和公理都被這些專家進行了評估和驗證。我們評估邏輯交通控制是基于理論知識的。在這個過程中進行了兩項活動，包括檢查的要求和能力的問題，并在目標應用環境測試本體。由于邏輯交通控制已建成的基礎上，如指定要求優化循環時間，逐步淘汰型，交通的移動和優化綠燈時間，每個階段的序列中，第一項活動是最好的結果。邏輯交通控制滿足所有的交通燈控制的需求，并能回答的能力問題。績效評估機制，可以支持這種說法。在部分實驗結果我們驗證了這一過程。

第四篇：外文翻譯

Low Voltage Flyback DC-DC Converter For

Power Supply Applications Hangzhou Liu1, John Elmes2, Kejiu Zhang1, Thomas X.Wu1, Issa Batarseh1

Department of Electrical Engineering and Computer Science, University of Central Florida, Orlando, FL 32816, USA Advanced Power Electronics Corporation, Orlando, FL 32826, USA Abstract ：In this paper, we design a low voltage DC-DC converter with a flyback transformer.The converter will be used as a biased power supply to drive IGBTs.The flyback transformer using planar EI-core is designed and simulated using ANSYS PExprt software.Besides, anLT3574 IC chip from Linear Technology has been chosen for converter control.Finally, the converter modeling and simulation are presented and PCB layout is designed.Keywords：Flyback, anLT3574IC, PCB

I.INTRODUCTION The goal of this project is to develop and build a prototype of a high-efficiency, high-temperature isolated DC-DC converter to be used as a biased power supply for driving a complementary IGBT pair.It is important that the converter can deliver the required power at an ambient temperature of up to 100℃;therefore it has to be efficient so that its components do not exceed their maximum temperature ratings.The final converter will be completely sealed and potted in a metal case.The input voltage range for this converter is from 9V to 36V.The output sides have two terminals, one is﹢16V and the other one is﹣6V.In order to get the desired performance, anLT3574 IC chip from Linear Technology is used.The key to this design is the flyback transformer.The transformer using planar EI-core is designed and simulated using ANSYS PExprt software.Finally, the PCB layout of the converter will be presented.II.KEY DESIGN OUTLINE For this flyback topology, the output voltage can be determined by both the transformer turns ratio and the flyback loop resistor pairs.Therefore, at the initial design stage, we can choose a convenient turn’s ratio for the transformer, and modify it later on if necessary to make sure the output performance is desirable and the transformer will not saturate [1].The relationship between transformers turns ratio and duty cycle can be found as

Where n is the transformer turns ratio, D is the duty cycle, VO` is the sum of the output voltage plus the rectifier drop voltage, VIN is the input voltage of the transformer.The value of feedback resistor can be calculated as

Where RREF is the reference resistor, whose value is typically 6.04k?;α is a constant of 0.986;VBG is the internal band gap reference voltage, 1.23V;and VTC is normally 0.55V [1].With a specific IC chosen, the converter circuit can be designed based on a demo circuit and some parameters may need to be modified if necessary to optimize the performance.Furthermore, in LT Spice, a large number of simulations need to be done with different conditions such as load resistor values and input voltage levels.It is important to make sure that the output voltage can be regulated well with all these different conditions.The most critical part of the design is the flyback transformer.With high switching frequency, the AC resistance can only be estimated based on some traditional methods such as Dowell’s curve rule [2].In order to get more accurate values of AC resistance values;we propose to use finite element electromagnetic software ANSYS PExprt to do the design [3].At the initial design stage, key parameters such as the worst-case input voltage, frequency, material, inductance values will be decided.After that, these data will be imported to the software, from which an optimized solution will be generated.III.CONVERTER SIMULATION RESULTS We choose LT3574 chip in this design.From the simulation results in Figure 1 and Table 1, it clearly shows that the output voltages which are﹢16V and-6V respectively can be regulated pretty well with the input voltage range from 9V to 36V.The voltage tolerance ranges are from ﹢15V to ﹢19V and-12V toDC converter for low voltage power supply application has been designed.The modeling and simulation results are presented.Based on the design specifications, a suitable IC from Linear Technology is chosen.A large amount of circuit simulations with different conditions such as load resistor values and input voltage levels are presented to get the desirable output voltage and current performance.The transformer has been designed including electrical, mechanical and thermal properties.With all the specific components decided, the PCB layout of the converter has been designed as well.REFERENCE

[1] Linear Technology Application Notes , Datasheet of Isolated Flyback Converter Without an Opto-Coupler, http://cds.linear.com/docs /Datasheet/3574f.pdf.[2] P.L.Dowell, “Effect of eddy currents in transformer windings” Proceedings of the IEE, NO.8 PP.1387-1394, Aug 1966.[3] S.Xiao, “Planar Magnetics Design for Low-Voltage DC-DC Converters” MS, 2004.[4] ANSYS Application Notes, PEmag Getting Started: A Transformer Design Example, http://www.tmdps.cn/download/ EDA/Maxwell9/planarGS0601.pdf.[5] K.Zhang;T.X.Wu;H.Hu;Z.Qian;F.Chen.;K.Rustom;N.Kutkut;J.Shen;I.Batarseh;“Analysis and design of distributed transformers for solar power conversion” 2011 IEEE Applied Power Electronics Conference and Exposition(APEC), v l., no., pp.1692-1697, 6-11 March 2011.[6] Zhang.;T.X.Wu.;N.Kutkut;J.Shen;D.Woodburn;L.Chow;W.Wu;H.Mustain;I.Batarseh;,“Modeling and design optimization of planar power transformer for aerospace applic ation,” Proceedings of the IEEE 2009 National, Aerospace & Electronics Conference(NAECON), vol., no., pp.116-120, 21-23 July 2009.[7] Ferroxcube Application Notes, Design of Planar Power Transformer,

第五篇：外文翻譯

微孔的加工方法

正如宏觀加工一樣，在微觀加工中孔的加工也許也是最常用的加工之一。孔的加工方法有很多種，每一種都有其優點和缺點，這主要取決于孔的直徑、深度、工作材料和設備要求。這篇文章主要介紹了內冷卻鉆頭鉆孔、無冷卻鉆孔、插銑、電火花以及激光加工微孔的幾種方法。

易于孔加工的操作

無論孔有多大，在加工時將冷卻液導入到刀尖，這都有助于排屑并能降低刀具和工件表面產生的摩擦熱。尤其是在加工深細孔時，有無冷卻液對加工的影響更大，因為深細孔加工的刀具比較脆弱，再加上刀具對切屑的二次切削和切屑的堆積會積累大量的熱，而熱量是碳化物刀具的主要“天敵”，它會加快刀具的失效速度。

當使用外冷卻液時，刀具本身會阻止切削液進入切削加工位置。也就是到3-5倍的直徑深度后切削液就會很難流入到刀尖。副哈維工具有限公司的副總工程師杰夫戴維斯說，這時就該選用帶有內冷卻液的鉆頭。

另外，在加工小孔時采用的外冷卻液的冷卻方式產生的利要大于弊，當鉆頭進入工件時，已經流入孔的冷卻液產生的壓力有時會繳壞鉆頭，戴維斯說。

刀具生產商提供的標準鉆頭的直徑從0.039到 0.125英寸，能加工深度小雨12倍的直徑的深孔，同時提供直徑從0.002到0.020英寸的不帶內冷卻液的鉆頭。

盡管有內冷卻能力，但還是不夠的，冷卻液需要一定的流動速度從而能夠將切屑清出孔外。戴維斯強調，冷卻液的最低壓力應為600-800磅/平方英寸，加工狀況還會隨著所施加的壓力的增加而提高，他補充道。

為了防止這些冷卻液通口被雜物堵塞，戴維斯還推薦在鉆頭加上一5微米孔徑或更加精密的冷卻液濾清器。

另外，他還推薦在加工孔時有必要在工件的上方先技工一個定心或導向孔，以防止刀具偏斜，并有助于保證所加工孔的垂直度。當選用定心鉆時，應使選擇的定心鉆刀尖上的坡口角小于等于其后內冷鉆的坡口角。定心鉆的直徑還要稍微大一些。例如，如果定心鉆的坡口角為120，內冷卻鉆頭的坡口角為140，并且定心鉆的直徑小于內冷卻鉆的直徑。在加工時內冷卻鉆的拐角處會與定心孔干涉而容易脫落，戴維斯說：這將導致鉆頭損壞。

雖然沒加強調，但是加工細深孔時，喙式進給是一種很好的加工方式。戴維斯建議，根據工件的材料不同。每次喙式進給的深度最好為孔徑的30%--50%。這種加工方式便于排出切屑，使切屑不在加工孔中堆積。潤滑及冷卻

為了更加有助于徘屑，戴維斯推薦在金屬加工中使用油基金屬切削液代替水基冷卻液，因為油具有較高的潤滑效果。但是如果車間更加青睞于使用水基冷卻液，液體中應該包括EP（極壓）添加劑，增加潤滑和減少發泡。如果產生很多泡沫，戴維斯說，“切屑就不會按著預定的方式排出。”

他還補充道，另一種提高潤滑并且提高刀具壽命的方法是道具涂層，例如氮鋁化鈦（TiAIN)。TiAIN具有很高的硬度,當鉆削像不銹鋼這樣的難加工金屬材料時，帶有TiAIN涂層的刀具能有效的減少熱沖擊。

威斯康星洲簡斯維爾微型刀具公司的總經理大衛伯頓，對微加工刀具的小批量涂層有不同的看法，他說：“對直徑小于0.020英寸的刀具涂層，會對刀具的加工質量到刀具壽命等每一加工方面都產生消極影響”。因為小刀具涂層不能做的足夠薄，這樣涂層就會改變刀具的前角和后角，從而不利于加工。

不過，更薄的涂層的開發正在繼續，伯頓表示，現在微型刀具公司除了生產銷售微型銑刀、刨刀和微型鉆頭外，還在和其他公司合作致力于開發一種亞細微涂層。伯頓說：“我們計劃這種涂層刀君會在六月到一年的時間內上市”。

微型鉆公司的產品主要是用于電路板加工鉆頭，但也可用于有效的切屑金屬。所有的刀具都沒帶內冷能力。“我有一個客戶想要在不銹鋼上面鉆一個0.004英寸的孔，他當時非常驚訝這能用一把加工電路板的鉆頭完成”。伯頓還補充到，采用喙式進給并選擇高的主軸速度可以提高鉆頭的效率。

微加工刀具要使用多高的轉速，這主要依賴于車間所使用的數控機床和刀具的直徑，所需的轉速隨刀具直徑的增加而加快（注：切削速度公式為 sfm=刀具直徑×0.26×主軸轉速）。

雖然相對較低，但伯頓的客戶也成功 的應用過每分鐘5000轉的加工速度。伯頓說：“我們建議我們的用戶找到一個震動最小的最高轉速-----最佳加工速度。”

為了減少震動，在用小的切削力通過刀具的前傾面的去除適當的金屬時，應使滲入到工件中的切削載荷連續而充足，如果鉆頭承受的切削載荷太輕，刀具前傾面的磨損速度就會加快，刀具變鈍，從而影響刀具的使用壽命。這在加工細孔時應更加注意。

“用戶們常常使用較輕的切削載荷來延長刀具的使用壽命，”伯頓說，“這恰恰會加快切削刃的磨損，并在刀刃寬出切屑的位置形成圓弧，刀具會變得像磨削工具一樣把材料強行除掉，只能成為廢刀。”伯頓認為，直徑大于0.001英寸的刀具切削抗力小于0.0001時，切削力抗力就已經太小了，即使刀具不會斷裂，過早的摩擦也會導致刀具壽命縮短。

太多的跳動也可能是破壞性的，但是影響有多少還值得商榷。伯頓指出，公司打算設計一臺具有0.0003英寸偏差的機器，用以建立室內最壞情況下的銑削場景，還將能夠加工0.004英寸寬的槽。“這遲早會實現的”。

他還補充：“你還可以試想一下0.0003英寸的跳動和只有正常水平三分之一的切削載荷，也就是說0.0001到0.00015，刀具將會立即破壞，因為刀具的一個徘屑槽會承受所有的載荷，然后徘屑槽的后面就會破壞。”

他還指出，在鉆孔時，小于0.0003英寸的偏差是可以接受的，因為當鉆頭深入孔內時，鉆頭末端的切削刃在外圓柱非加工表面的引導下會繼續切削。偏差的最小值隨著深度和直徑比值的增加而迅速減少，這是因為當鉆頭越深入工件，徘屑槽的吸震能力越差。最后強烈的跳動導致刀柄繞著刀具的軸線轉動，而刀尖還仍然保持穩定，從而產生是刀具最終斷裂的集中應力。插銑

雖然通常沒有直徑小于0.002英寸的標準微型鉆頭，但可以用微型端銑刀來“沖”孔。“每當人們想加工一個小于0.002英寸的孔時，他們可以選用端銑刀，效果也不錯。”伯頓說道。但這樣加工的孔不能太深，因為刀具體不長，沒有大的深度直徑比率，因此一把直徑為0.001英寸的端銑刀只能加工最深0.20英寸的孔，而同樣直徑的鉆頭可以加工得更深，因為鉆頭的設計使載荷全部作用在刀尖上，進而傳到刀柄上被吸收。

市面上能提供最小5微米的端銑刀，但是并沒有大量銷售。“當人們想買這樣的刀具時，我非常嚴肅的試著說服他們不要買，因為我們不喜歡制作這樣的刀具。”伯頓說到。這種刀具主要問題是。不但這種刀具的硬質合金齒處于亞細微尺寸，而且當一把刀有多個齒時，每個齒的尺寸還要保持一致。伯頓道：“一把直徑5微米的端銑刀在其基體上就夾持大約10個刀齒。”

他還補充說，他曾經看到過帶有0.微米的粉末冶金硬質合金刀具，這是商業上能提供齒的尺寸的一半，但它還包括0.5和0.6微米的小齒。“如果齒的尺寸不統一，小齒是發揮不出作用的。” 墜電火花加工

應用墜電火花的電火花加工是一種微孔加工方式。這不同于將電導線穿過工件的電火花加工方式，應用墜電火花加工的微孔更加精密和精確，但同時花費也會很高。

墜電火花加工深細孔時，要用一根導電管作為電極。加工小而淺的孔時，需要用到一根導線或棒，“我們盡量用導管做電極。位于密歇根州的牧野公司總經理Jeff Kiszonas說道，導管的排渣孔能使加工的孔有大的深度直徑比，并能夠在加工中將孔底的熔渣排出孔外。他又補充道”但是另一方面，沒人能制造出小于一定直徑的導管。“一些供應商能提供直徑小于0.003英寸的導管可以加工出0.0038英寸的孔。

現在Makino公司生產的雙邊墜電火花加工設備能夠加工出 0.00044 英寸的微孔，這種設備主要用于孔的精加工。最近，在日本這種機床的開發人員用兩分鐘加工了八個這樣的孔，并用四十秒穿透了0.0010英寸厚的碳化鎢板。加工電極為一個因鎢合金棒，由于電火花加工中再電極和工件間存在放電間隙，所以，所加工孔的直徑會比電極直徑大0.00020英寸。

當加工上述尺寸的孔時，旋轉的導棒上包裹著通電的放電導線。精加工時需要一個w軸附件，用來夾持電極導向的模具，另外還需要一個中間導向件，當電極旋轉時用來防止其彎曲和擺動。應用這種加工方式的機床適合于加工直徑小于0.005英寸的孔。

另一種墜電火花加工微型孔機床是三菱VA10機床，它用精加工孔的鉆摸附件來裝卡和引導精制導線來腐蝕金屬，伊利諾伊州的MC機械系統公司產品加工經理丹尼斯德利說：“這是一種標準的電火花加工，但是借助于安裝在機器上的附件，我們同樣可以加工細孔”。他還補充說在電火花加工中用2000轉/分的轉速旋轉的導線可以加工小于0.0004英寸的孔。鎢電極電火花加工

電火花加工是一中典型的慢加工，加工微孔時這表現得也很明顯。“電火花加工非常慢，并且隨著加工精度的增加而減慢”Midvale公司（Midvale公司是一個位于猶他州，主要生產24伏低電壓電火花加工設備和基于精密電火花加工的公司）的總裁迪恩約根森說。

鎢電極的生產是應用反極性接法，經機械加工、研磨加工使之直徑達到10微米、粗糙度為0.000020英寸。應用1-微米的電極加工10.5到11微米的孔，并能加工盲孔。用于加工最小孔的最大工件厚度為0.002英寸，加工50微米直徑的孔時工件的厚度能達到0.004英寸。

在激光加工之后用電火花加工是生產高精度孔的一種比較不錯的方法，約根森已經決定重新研發最好的加工設備。“我們需要重新研發所有電子控件、程序軟件和機械”。約根森說重新研發這些軟件和繼續額需要花費180000到200000美元。

車間里多數精加工為100美元/小時，包括特殊金屬的電火花加工，如：X射線加工金和鉑、光加工不銹鋼、陰極射線加工鎢和鉭。約根森說道，電火花加工還不適合加工半導體材料，如聚晶金剛石。光加工

除了硬質合金和鎢電極外，光也是一個不錯的微孔加工的“刀具”材料。雖然大多數來鉆孔的激光都是處于紅外光譜范圍，但是根據賓尼法尼亞州的Ex One Co。、Iiwin公司的激光技術主管蘭迪吉爾摩介紹，他們采用的是綠色光柱的超脈沖技術。不像其他種類的微加工光束，超脈沖是一種納秒級激光，它綠色光束的波長為532納米。這種技術產生的激光一對脈沖時間為4到5納秒，每對脈沖的間隔為50到100納秒。這種技術的加工方式成倍的提高了加工效率。“與其他激光加工相比，這種技術大大的提高了金屬去除率”。吉爾摩說：“由于這種激光脈沖短，所以很大程度上減少了對工件材料的熱損傷。”

超脈沖激光加工孔的最小直徑為45微米，不過這種加工最常用在H系列鋼材料的柴油機噴嘴90微米到110微米孔的加工。吉爾摩提到，根據排放標準的要求這種孔的直徑要縮小到50微米到70微米，因為越小的孔越能使燃料充分燃燒。

另外，這種技術加工的孔還帶有一個負的錐度，就是入口直徑小于出口直徑，這有利于燃料的流動。

這種技術的另一種常用的應用是在航空渦輪葉片上打冷卻孔。雖然葉輪只有1.5mm到2mm厚，但吉爾摩解釋說，這種孔要帶有25°的入口傾角，以使冷空氣貼著孔壁流動，更好的起到冷卻作用，這就是說鉆孔的長度達到5mm。他說：“溫度是航空發動機的主宰，葉輪運行的環境溫度越高，燃料的利用率越高，得到的推力越大。

為了加強這技術的競爭力，Ex One 公司研發了一種專利材料，將這種材料注入中空的部件體內，可以防止光柱所加工孔以下壁體的燒傷。光加工之后，可以將這種材料完全清理掉。

“光加工的一種缺點是，光柱在遇到另一個實體之前就會一直傳播”吉爾摩說：“加工柴油機噴嘴時，這會損壞相對壁的內表面”。

超脈沖加工設備的價格為650000到800000美元，雖然這要高于電火花加工設備，但是光加工不會用到電極。“激光加工用光做刀具”吉爾摩說：“它節省了電極的開支”。

根據其應用的不同，機械鉆削加工、插銑、電火花加工和光加工在微孔加工中都占有一席之地。牧野公司的Kiszonas說：“用戶也比較向往有更多的微孔加工方法供其選擇”。