第一篇：網絡安全外文翻譯[模版]

附件1：外文資料翻譯譯文

網絡安全 簡介

在計算機網絡最初出現的幾十年里，它主要用于在各大學的研究人員之間傳送電子郵件，以及共同合作的職員間共享打印機。在這種條件下，安全性未能引起足夠的注意，但是現在，眾多的普通市民使用網絡來處理銀行事務、購物和納稅，網絡安全逐漸成為一個潛在的巨大問題。

安全性是一個涉及面很廣的問題，其中也涉及到是否構成犯罪行為的問題。大多數安全性問題的出現都是由于有惡意的人試圖獲得某種好處或損害某些人而故意引起的。

網絡安全性可以被粗略地分為4個相互交織的部分：保密、鑒別、反拒認以及完整性控制。保密是指保護信息不被未授權者訪問，這是人們在談到網絡安全性時最常想到的問題。鑒別主要指在揭示敏感信息或進行事務處理之前先確認對方身份。反拒認主要與鑒別有關：當你的客戶下了一份要采購1000萬雙手套的訂單，后來他宣稱每雙的價格是69美分，如何證明他原先答應的價格是89美分呢？最后，如何確定自己收到的消息是最初發送的那條消息，而不是被有惡意的敵人篡改或偽造過的呢？所有這些問題（保密、鑒別、反拒認和完整性控制）也發生在傳統的系統中，但卻有很大的差別。

在討論解決方法之前，值得花些時間考慮網絡安全性屬于協議組的哪一部分的內容。可能無法確定一個單獨的位置，因為安全性與每一層都有關。以下將從不同的角度來介紹網絡安全性。計算機病毒

在我們這個富有健康意識的社會中，任何形式的病毒都是敵人。計算機病毒則尤其是個禍害。這類病毒可以、也的確侵襲過沒有防范的計算機系統，輕者可能僅僅是惹人心煩，重者可能造成災難性的軟件及數據損失，導致時間及財力的浪費。各家公司越來越多地使用計算機進行企業管理，這對于企業來說是至關重要的。然而，隨著計算機病毒威脅的出現，病毒引發的系統癱瘓屢有發生，其代價正不斷增長。我們應當關注這一問題，但恐慌是沒有必要的。正如良好的飲食、運動及醫療保健可以延年益壽一樣，謹慎高效的防病毒策略也可以最大限度地減少病毒入侵的機會。

計算機病毒到底是什么？

計算機病毒是一種人為設計的、可以自我復制及傳播的計算機程序。一般來說，受害人對于病毒的存在并不知曉。計算機病毒可以將自身附加到其他程序（如文字處理或電子表格應用程序文件）或磁盤的引導扇區中，并借此傳播。如果執行（激活）已感染了病毒的程序，或從感染了病毒的磁盤上引導系統，病毒程序也同時執行。通常，病毒程序隱藏于系統內存中，等待著感染下一個被激活的程序或下一個被訪問的磁盤。

病毒的危險性在于其執行事件的能力。盡管有些病毒是良性的（例如，在某一日顯示某種提示信息），但也有一些病毒令人心煩（如降低系統性能或篡改屏幕信息），更有一些病毒會破壞文件、銷毀數據、導致系統癱瘓，而這將是災難性的。

病毒程序有哪幾種？

有4種主要類型的病毒：外殼型、入侵型、操作系統型和源代碼型。外殼型病毒包圍在主程序的四周，對源程序不做修改。外殼型病毒較易編寫，因此約半數的病毒程序是這種類型。

入侵型病毒入侵到現有程序中，實際上是把病毒程序的一部分插入主程序。入侵型病毒難以編寫，不破壞主文件，很難去除這種病毒。

外殼型和入侵型病毒通常都是攻擊可執行程序文件，即帶有.COM或者.EXE擴展名的文件。但數據文件也有受攻擊的危險。

操作系統型病毒是用它們自己的邏輯代替部分操作系統。這些病毒程序的編寫非常困難，它們一旦發作就能控制整個系統。

源代碼型病毒是入侵程序，它們在程序被編譯之前插入到源程序中，它們是最少見的病毒程序，因為它們不僅編寫困難，而且與其他類型的病毒相比，受破壞的主程序數目也有限。防火墻

當把你的局域網連接到Internet后，你的用戶就能夠與外部世界進行接觸和通信聯系。然而，同時也讓外界能進入你的局域網并相互產生影響。防火墻只是古代中世紀防御方法——在城堡周圍挖一條深深的護城河的一種現代應用。使得每個進出城堡的人必須通過一條吊橋，在那里他們受到守橋衛士的檢查。對網絡可以使用同樣的方法：一個公司可能有許多的局域網，它們以任意的方式連接，但是所有流進、流出公司的信息流都必須通過一個電子吊橋（防火墻）。

防火墻實質上是一個獨立的進程或一組緊密結合的進程，運行在路由器或服務器上以控制經過防火墻的網絡應用程序的信息流。一般來說，防火墻置于公共網絡（如Internet）入口處。它們可以看做是交通警察。防火墻的作用是確保一個單位的網絡與Internet之間所有的通信均符合該單位的安全方針。這些系統基本上基于TCP/IP，它能根據實施情況設置安全路障并為管理員提供下列問題的答案：

誰一直在使用我的網絡？ 他們在我的網絡上做什么？ 他們在什么時間使用我的網絡？ 他們在我的網絡上去了何處？ 誰要連接我的網絡但沒有成功？

通常有3種類型的防火墻實現方案，其中某些可以一起使用以建立更安全的環境。這些實現方案是過濾包、應用程序代理和電路級通用應用程序代理。

包過濾通常是在路由器中實現的，而應用程序代理通常運行在獨立的服務器上。代理服務采取不同于各種包過濾的方法，使用（可能）修改過的客戶機程序與專用中間主機相連，而該主機又真正與所需的服務器相連。

(1)包過濾

把你的網絡數據看成一個你必須送到某個地方的干凈的小數據包。該數據可能是電子郵件、文件傳輸等的一部分。使用包過濾時，你自己來傳送此數據包。包過濾器起交通警察的作用，它分析你想到哪兒去，你隨身攜帶了什么。但包過濾不打開數據包，如果允許，你仍要把它送到目的地。

多數商品化的路由器都有某種內建的包過濾功能。然而，有些由ISP（Internet服務提供商）控制的路由器不可能給管理人員提供控制路由器配置的能力。在這些情況下，管理人員可能選擇使用接在路由器后面的獨立包過濾器。

不管哪種方法，管理人員都需要知道如何按包過濾器能理解的術語來識別數據包。由于所有Internet信息流都是基于IP（Internet協議），故通過特定的TCP（傳輸控制協議）或UDP（用戶數據報文協議）端口可以識別每個應用程序或“數據包”。這些端口都在RFC1700中登記和定義。RFC（請求注解）1700可在Internet上找到。例如，Telnet的端口是23。公司可以阻攔所有端口為23的IP包進入。用這種方法，公司外面的人都不能通過遠程登陸進來。

(2)應用程序代理

為理解應用程序代理，來看一看這樣的情況，你需要遞交一個干凈的小網絡數據包。用應用程序級代理，情況是相似的，但現在你需要依靠另外一個人來為你傳遞此數據包。因此，術語“代理”說明了這個情況。包過濾適用的規則也適用應用程序代理，有一點不同，即你不能越過應用程序代理遞交包。有人會為你做事，但此代理人首先要看一下包的內部來確認其內容。如果代理已有遞交該包的內容的許可，他就會為你遞交。

雖然筆者相信，將來代理技術會融合進路由器的程序代碼中，但今天多數商品化的路由器都不具備代理功能。迄今，你還是需要依靠能支持應用程序級代理服務的獨立系統。

由于應用代理需要代表發送者進行通信，所以它需要懂得與特定應用程序相關聯的具體語言或協議。以廣泛使用的HTTP（超文本傳輸協議）代理為例，如果你在網絡上使用瀏覽器，那么可能的情況是信息系統部門有一配置成允許你通過的中央服務器訪問Web的HTTP代理。這臺機器懂得HTTP對話，能代表請求的客戶說話。這就是應用程序級的代理。

當然，由于代理必須有能力打開“包”來進行查看或者對其內容進行譯碼，所以安全和加密問題隨之而來。顯然這些是很重要的問題，但充分討論這這些問題需要另寫一篇文章。

(3)電路級或通用應用程序代理

與應用程序代理一樣，你需要依靠某個人來為你傳遞數據包（對于電路級代理），區別是，如果這些電路級代理要把數據包遞交到你要求的目的地時，它們就會這么做。它們不需要知道內容是什么。

電路級代理（尤其是SOCKS）工作在應用層協議的外面。這些服務器允許客戶機通過此集中服務，并接到連接請求的源地址，并通過SOCKS客戶程序庫對它們進行重新編譯和鏈接來阻斷未經許可的客戶機接到Internet上。基于DLL的TCP組還具有另外一個好處，即能通過使用墊片向應用程序提供SOCKS客戶機能力，而不再需要重新編譯。附件2：外文原文（復印件）

Network Security 1 Introduction For the first few decades of their existence,computer networks were primarily used by university researchers for sending email,and by corporate employees for sharing printers.Under these conditions,security did not get a lot of attention.But now,as millions of ordinary citizens are using networks fou banking,shopping,and filing their tax returns,network security is looming on the horizon as a potentially massive problem.Security is a broad topic and covers a multitude of sins.Most security problems are intentionally caused by malcious people trying to gain some benefit or harm someone.Network security problems can be divided roughly into four intertwined areas:secrecy,authentication,non-repudiation,and integrity control.Secrecy has to do with keeping information out of the hands of unauthorized users.This is what usually comes to mind when people think about network security.Authentication deals with determining whom you are talking to before revealing sensitive information or entering into a business deal.Non-repudation deals with signatures:how do you prove that your customer really placed an electronic order for ten million letf-handed doohickeys at 89 cents each when he laterclaims the price was 69 cents?Finally,how can you be sure that a message you received was really the one sent and not something that a malicious adversary modified in transit or concocted?And all thes issues(secrecy,authentication,non-repudiation,and integrity control)occur in traditionl systems,too,but with some significant differences.Before getting into the solution themselves,it is worth spending a few moments considering where in the protocol stack network security belongs.There is probably no one single place.Every layer has something to contribute.In the following sections,we will study network security from several angles.2 Computer Virus

In our health-conscious society,viruses of any type are an enemy.Computer viruses are especially pernicious.They can and do strike any unprotected computer system,with results that range from merelyannoying to the disastrous,time-consuming and expensive loss of software and data.And with corporations increasingly using computer for enterprise-wide,business-critical computing,the costs of virus-induced downtime(the time during which a machine,esp.a computer is not working or is not able to be used).are growing along with the threat from viruses themselves.Concern is justified—but unbrdled paranoia is not.Just as proper diet,exercise and preventive health care can add years to your life,prudent and cos effective anti-virus strategies can minimize your exposure to computer viruses.What is Virus? A computer virus is a program designed to replicate and spread on its own,generally with the victim being oblivious to its existence.Computer viruses spread by attaching themselves to other programs(e.g.,word processor or spreadsheet application files)or to the boot sector of a disk.When an infected file is actvated,or executed ,or when the computer is started from an infected disk,the virus itself is also executed.Often,it lurks in computer memory,wating to infect the next program that is activate,or the next disk that is accessed.What makes viruses dangerous is their ability to perform an event.While some events are benign(e.g.,displaying a message on a certain date)and others annoying(e.g.,slowing performance or altering the screen display),some viruses can be catastrophic by damaging files,destroying data and crashing systems.What Kinds of viruses Are There? There are four main types of viruses:shell,intrusive,operating system,and source code.Shell viruses wrap themselves around a host program and do not modify the orginal program.Shell programa are easy to write,which is why about half of all viruses are of this type.Intrusive viruses invade an existing program and actually insert a portion of themselves into the host program.Intrusive vruses are hard to write and very difficult to remove without damaging the host file.Shell and intrusive viruses most commonly attack executable program files—those with a.COM or.EXE extension—although data files are also at some risk.Operating system viruses work by replacing parts of the operating system with their own logic.Very difficult to write,these viruses have the ability,once booted up,to take total control of your system.Source code viruses are intrusive program that are inserted into a source program prio to the program being compiled.They are the least common viruses because they are not only hard to write,but also have a limited number of hosts compared to the other types.3 Firewall When you connect your LAN to the internet,you are enabling your users to touch and communicate with the outside world.At the same time,however,you are enabling the outside world to touch and interact with your LAN.Firewalla are just a modern adaptation of that old medieval security standby:digging a deep moat around your castle.This design forced everyone entering or leaving the castle to pass over a single drawbridge,where they could be inspected by the I/O police.With networks,the same trick is possible:a company can have many LANs connected in arbitrary ways, but all traffics to or from the company is forced through an electronic drawbridge(firewall).Basically,a firewall is a standalone process or a set of integrated processes that runs on a router or server to control the flow of networked application traffic passing through it.Typically,firewalla are placed on the entry point to a public network such as the internet.They could be considered traffic cops.The firewall’s role is to the organization’s security policies.Primarily these system are TCP/IP based and,depending on the implementation,can enforce security roadblocks as well as provide administrators with answers to the following questions: Who’s been using my network? What were they doing on my network? When were they using my network? Where were they going on my network? Who failed to enter my network? In general,there are three types of firewall implementations,some of which can be used together to create a more secure environment.These implementations are:packek filterng,application proxies,and circuit-level or generic-application proxies.Packet filtering is often achieved in the router itself.Application proxies,on the other hand,usually run on standalone servers.Proxy services take a different approach than packet filters,using a(possibly)modfied client program that connects to a special intermediate host that actually connects to the desired service.(1)Packet Filtering Consider your network data a neat little package that you have to deliver somewhere.This data could be part of an e-mail,file transfer,etc.with packet filtering,you have access to deliver the package yourself.The packet filter acts like a traffic cop;it nanlyzes where you are going and what you are bringing with you.However,the packet filter does not open the data package,and you still get to drive it to the destnation allowed.Most commercial routers have some kind of built-in packet filtering capability.However some routers that are controlled by ISPs may not offer administrators the ability to control the configuration of router.In those cases, administrators may opt to use a standalone packet filter behind the router.Either way,an administrator needs to understand how to identify data packages in terms the packet filter can understand.Since all Internet traffic is based on IP(Internet Protocol),each application or“package”can be identified through a specific TCP(Transmission Control Protocol)or UDP(User Datagram Protocol)Port.These ports are registered and defined in RFC(Request for Comment)1700 which can be found on the internet.For example,port 23 is for Telnet.A company could block incoming packets for all IP addresses combined with port 23.In this way,no one outside the company could log in via Telnet.(2)Application Proxy To understand the application proxy,consider this scenario where you need to deliver your neat little package of network data.With application-level proxies,the scenario is similar,but now you need to rely on someone else to deliver the package for you.Hence the term proxy illustrates new scenario.The same rules apply as they do for packet filtering,except that you don’t get to deliver your package past the gate.Someone will do it for you,but that agent needs to look inside the package first to conform its contents.If the agent has permission to deliver the contents of the package for you,he will.Most commercial routers do not have proxy capabilties today,although we believe that proxy technology will be integrated with router in the future.Until then,you need to rely on a standalone system that can support application-level proxy services.Since an application proxy needs to communicate on behalf of the sender,it needs to understand the specific language or protocols associated with a particular application.Take as an example the widely used HTTP(Hypertext Transfer Protocol)proxy.If you are using a browser on your network,it is highly likely that your IS group has an HTTP proxy configured to allow you to access the Web via a central server.That single machine understands HTTP conversations and speak on behalf of the requesting client.This is application-level proxy.Of course,security and encryption also come into play,since the proxy must be able to open the “package”to look at or decode its contents.These are important issues obviously,but to do them justice would require another article.(3)Circuit-Level or Generic-Application Proxy As with application-level proxy,you need to rely on someone to deliver your package for you.The difference is that if these circuit-level proxies have access to deliver the package to your requented destination,they will.They do not need to know what is inside.Circuit-level proxies(specifically SOCKS)work outside of the application layers of the protocol.These servers allow clients to pass through this centralized service and onnect to source address of connection requests and can block unauthorized clients from connecting out onto recompiling and linking them with a SOCKS client library.DLL-based TCP stacks have the use of shims,eliminating the need to recompile.

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

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

第五篇：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,