第一篇：外文及翻譯

ZHEJIANG SHUREN UNIVERSITY

《學(xué)科前沿文獻(xiàn)讀寫議》課程作業(yè)

學(xué)生姓名： 沈焱強(qiáng) 學(xué)

號(hào)： 201001013335 專

業(yè)： 工商管理 班

級(jí)： 工本103班

浙江樹人大學(xué)管理學(xué)院

畢業(yè)論文題目：浙江農(nóng)村養(yǎng)老保險(xiǎn)調(diào)查分析 外文文獻(xiàn)翻譯

重新引入代際均衡：波蘭養(yǎng)老保險(xiǎn)制度

馬立克：GóRA 威廉戴維森學(xué)院工作論文574號(hào) 2003年6月

摘要：波蘭于1999年通過了新的養(yǎng)老金制度。這種新的養(yǎng)老保險(xiǎn)制度允許波蘭，以減少退休金支出（占GDP的百分比），而不是增加它-正如預(yù)計(jì)的經(jīng)合組織其他大多數(shù)國(guó)家。本文介紹了概念背景的新系統(tǒng)的設(shè)計(jì)。新系統(tǒng)的長(zhǎng)期目的是確保人口代際平衡，不論情況。這需要穩(wěn)定的國(guó)內(nèi)生產(chǎn)總值的份額分配給整個(gè)退休一代。傳統(tǒng)的養(yǎng)老金制度的目的，相反，在穩(wěn)定的份額人均國(guó)內(nèi)生產(chǎn)總值退休人員。在人口結(jié)構(gòu)的變化觀察到，在過去的一夫妻幾十年，這歷史性的嘗試，以穩(wěn)定為首占GDP的比重為退休人員嚴(yán)重的財(cái)政問題和經(jīng)濟(jì)增長(zhǎng)負(fù)外部性，如觀察許多國(guó)家。許多國(guó)家曾試圖改革其養(yǎng)老金制度不同的方法來嘗試解決這些不斷增加的費(fèi)用問題。雖然波蘭改革采用了其他地方應(yīng)用技術(shù)，它的設(shè)計(jì)不同于典型的做法和教訓(xùn)，結(jié)果是有希望的所有經(jīng)合組織國(guó)家。本文介紹了這一理論和實(shí)際應(yīng)用另一種方法，因此，新的波蘭養(yǎng)老保險(xiǎn)制度主要特點(diǎn)設(shè)計(jì)。

導(dǎo)言

人口結(jié)構(gòu)的轉(zhuǎn)型與政策過于短視一起造成了嚴(yán)重的問題在全世界許多國(guó)家地區(qū)的養(yǎng)老金。傳統(tǒng)的要素養(yǎng)老金制度的設(shè)計(jì)包括對(duì)捐款的薄弱環(huán)節(jié)和利益缺乏超過該系統(tǒng)的成本控制。這些因素列入養(yǎng)老保險(xiǎn)制度導(dǎo)致爆炸的設(shè)計(jì)成本，造成了負(fù)增長(zhǎng)的外部因素和導(dǎo)致失業(yè)率持續(xù)高企。因此，養(yǎng)老金改革的追求現(xiàn)已在世界各地，特別是在歐洲的政策議程的頂部。然而，很少有國(guó)家能夠在引進(jìn)根本性的改革面積到了這個(gè)時(shí)候養(yǎng)老金。在這種情況下，改革的定義是至關(guān)重要的。對(duì)于本文的目的，“改革”是指改變系統(tǒng)，以消除而不是僅僅在邊緣玩的貢獻(xiàn)率時(shí)下絕大多數(shù)平均擁有多年的生活留下來住。因此，上面的討論表明，養(yǎng)老保險(xiǎn)制度的目標(biāo)已經(jīng)改變了養(yǎng)老退休金系統(tǒng)（OA）的一部分。然而，非養(yǎng)老社會(huì)保障制度（NOA），如殘疾，保持風(fēng)險(xiǎn)有關(guān)，不論老化。這將導(dǎo)致社會(huì)保障體系的各部分的結(jié)論是，應(yīng)采用分段，如收入（貢獻(xiàn)）和費(fèi)用（利益）可以連接到他們的目的完全隨著時(shí)間的推移，各分部相互絕緣。

在這種方式中，決策者將能夠看到各分部的社會(huì)保障體系，知道系統(tǒng)其他部分的風(fēng)險(xiǎn)，其收入和支出都被絕緣的當(dāng)前狀態(tài)，準(zhǔn)確地反映了該分部的和共同的系統(tǒng)作為一個(gè)整體。社會(huì)保障體系，然后將一個(gè)OA段（養(yǎng)老金）和各的NOA段（殘疾，生育，工人的補(bǔ)償?shù)鹊龋?。這種業(yè)務(wù)和會(huì)計(jì)改革是最重要的一個(gè)深養(yǎng)老保

險(xiǎn)制度改革的非財(cái)政的原因之一，并為決策者提供一個(gè)功能強(qiáng)大的工具來了解如何以及他們的社會(huì)保障體系，將滿足其目標(biāo)。養(yǎng)老金：所提出的方法的總結(jié)

典型的養(yǎng)老金經(jīng)濟(jì)學(xué)，以及流行的討論，使用下面的對(duì)立概念為思考中心基礎(chǔ)養(yǎng)老金：

現(xiàn)付與資金；

公共與私人的；

多方面與多支柱。

本文提出了一種替代方法。這種替代方法，可以在以下四對(duì)對(duì)立的概念，總結(jié)了： 通用（強(qiáng)制覆蓋整個(gè)人口）和部分（一組人自愿參與）；

個(gè)性化（個(gè)人賬戶）與匿名（不）參與；

具體的任務(wù)/分段（OA與NOA）與多任務(wù)（OA和NOA混合在一個(gè)方案）社會(huì)保障組織；

金融（通過金融市場(chǎng)回報(bào)率）與非財(cái)務(wù)（通過真正的經(jīng)濟(jì)增長(zhǎng)產(chǎn)生的回報(bào)率）。

有效的養(yǎng)老保險(xiǎn)制度的一種方式，使內(nèi)源性的設(shè)計(jì)，這意味著它會(huì)自動(dòng)調(diào)整不干預(yù)外。系統(tǒng)只需要一個(gè)決定，即貢獻(xiàn)率的初步選擇。

基于比較的上面設(shè)置養(yǎng)老金的思維方式可以更好地描述和分析了養(yǎng)老保險(xiǎn)制度是有用的。這種方法也可以讓養(yǎng)老金討論超越那些促進(jìn)民辦養(yǎng)老基金和那些促進(jìn)所謂的現(xiàn)收現(xiàn)付制無望的爭(zhēng)議。

在歐盟等和其它地方的政策制定者可以使用所提出的方法的時(shí)候，看著他們的養(yǎng)老金制度改革。

波蘭新的養(yǎng)老保險(xiǎn)制度的主要特點(diǎn)

波蘭新養(yǎng)老保險(xiǎn)制度的設(shè)計(jì)是一個(gè)很好的例子應(yīng)用上述，介紹了在實(shí)踐中的思維方式。命名為“安全系統(tǒng)通過多樣性“1999年1月開始。它完全取代了以前的條例退休金的工作人口的大多數(shù)。設(shè)計(jì)新系統(tǒng)從從無到有提供了獨(dú)特的機(jī)會(huì)，以避免復(fù)雜的系統(tǒng)。相反，新系統(tǒng)的設(shè)計(jì)是簡(jiǎn)單和透明。主要目標(biāo)是設(shè)計(jì)一個(gè)系統(tǒng)可以是中性的，或者至少關(guān)閉經(jīng)濟(jì)增長(zhǎng)無論對(duì)中立人口老齡化。新系統(tǒng)的設(shè)計(jì)不復(fù)制任何其他現(xiàn)有的養(yǎng)老保險(xiǎn)制度在其他地方。很強(qiáng)的相似性，可以發(fā)現(xiàn)，只有到新的瑞典養(yǎng)老保險(xiǎn)制度根據(jù)類似的原則，并開始在同一時(shí)間對(duì)同一，在這一總體框架波蘭新系統(tǒng)采用了數(shù)字技術(shù)的概念在其他國(guó)家發(fā)展。這種新波蘭養(yǎng)老保險(xiǎn)制度的簡(jiǎn)要介紹對(duì)一般的系統(tǒng)經(jīng)濟(jì)性設(shè)計(jì)的重點(diǎn)，同時(shí)擱置最技術(shù)細(xì)節(jié)。下面的子彈協(xié)助抓的波蘭新概念的本質(zhì)系統(tǒng)設(shè)計(jì)。重點(diǎn)是普遍的養(yǎng)老保險(xiǎn)制度的一部分；

分離，社會(huì)保障的養(yǎng)老從非養(yǎng)老部分的一部分社會(huì)保障和分割的收入流； 終止了以前的系統(tǒng)辦公自動(dòng)化的一部分； 創(chuàng)建一個(gè)新的辦公自動(dòng)化系統(tǒng)完全養(yǎng)老金個(gè)人賬戶的基礎(chǔ)上； 權(quán)責(zé)發(fā)生制在辦公自動(dòng)化系統(tǒng)； 分裂兩個(gè)帳戶（第一帳戶中的每個(gè)人的辦公自動(dòng)化捐款北區(qū)區(qū)議會(huì)，第二個(gè)帳戶）；

最小的兩個(gè)補(bǔ)充養(yǎng)老年金頂部，如果他們的總和低于一定水平（資金，國(guó)家預(yù)算中）。

特別是有沒有這樣的元素作為一個(gè)“國(guó)家基本養(yǎng)老金”的制度。社會(huì)再分配的存在，但它被移動(dòng)從退休金制度。養(yǎng)老保險(xiǎn)制度的唯一的作用是提供一個(gè)有效的方法，對(duì)收入分配工作的一代人生命周期。對(duì)于整個(gè)社會(huì)保障體系的貢獻(xiàn)率并沒有改變。不過工人的工資是“票房注冊(cè)”，以便向他們介紹他們的想法，付出的貢獻(xiàn)的一部分，并建造了總成本的意識(shí)養(yǎng)老保險(xiǎn)制度。因此，自1999年1月工人和雇主分擔(dān)沒有任何費(fèi)用的捐款在捐款總額的大小真正的變化。該整個(gè)操作影響的百分比，但不是真正的金錢流動(dòng)。因此新的系統(tǒng)是基于以前的系統(tǒng)相同的貢獻(xiàn)流入。

結(jié)束語

為人們提供與社會(huì)保障-包括消費(fèi)融資的退休一代一代的產(chǎn)品進(jìn)行的工作-是非常高的名單在大多數(shù)國(guó)家的社會(huì)優(yōu)先事項(xiàng)。這是社會(huì)的重要，特別是在歐洲。然而，傳統(tǒng)的養(yǎng)老金制度的低效率在實(shí)現(xiàn)這一目標(biāo)的提出風(fēng)險(xiǎn)。社會(huì)和民眾主義言論向公眾表明，改變內(nèi)養(yǎng)老保險(xiǎn)制度是危險(xiǎn)的社會(huì)目標(biāo)。在現(xiàn)實(shí)中，大多數(shù)國(guó)家在世界上，它是剛好相反。時(shí)間越長(zhǎng)，傳統(tǒng)的養(yǎng)老金制度是舉起，在更多的社會(huì)造成的破壞性影響將被創(chuàng)建。波蘭屬于一個(gè)國(guó)家的非組，為眾多的人準(zhǔn)備我們的時(shí)間，即人口老齡化最嚴(yán)峻的挑戰(zhàn)。新養(yǎng)老保險(xiǎn)制度不僅將停止對(duì)養(yǎng)老保險(xiǎn)制度的成本增加，但會(huì)也讓他們減少。這將使更多的資源用于發(fā)展，這反過來也將有助于更強(qiáng)勁的增長(zhǎng)，加雙方的工作生活和退休一代的標(biāo)準(zhǔn)。波蘭新的養(yǎng)老金制度的例子，以及瑞典之一，有趣的另一個(gè)原因。這種類型的系統(tǒng)有利于勞動(dòng)力的流動(dòng)，這是特別需要在歐洲。免費(fèi)的勞工運(yùn)動(dòng)，就不可能實(shí)現(xiàn)如果從一國(guó)轉(zhuǎn)移到另一個(gè)影響到退休后的收入預(yù)期。因此，在養(yǎng)老保險(xiǎn)制度的中立性目標(biāo)將有越來越多的歐洲重要整合。

外文文獻(xiàn)原文

Reintroducing Intergenerational Equilibrium: Key Concepts behind the New Polish Pension System

By: Marek Góra William Davidson Institute Working Paper Number 574

June 2003

Abstract Poland adopted a new pension system in 1999.This new pension system allowsPoland to reduce pension expenditure(as a percent of GDP), instead of increasing itas is projected for the majority of other OECD countries.This paper presents theconceptual background of the new system design.The new system’s long-termbjective is to ensure intergenerational equilibrium irrespective of the demographicsituation.This requires stabilisation of the share of GDP allocated to the entire retiredgeneration.Traditional pension systems aim, instead, at stabilisation of the share ofGDP per retiree.The change in demographic structure observed over the past for acouple of decades and this historic attempt to stabilise the share of GDP per retiree ledto severe fiscal problems and negative externalities for growth, as observed innumerous countries.Many countries have tried to reform their pension systems indifferent ways to try to resolve the issue of these ever-increasing costs.Although thePolish reform uses a number of techniques applied elsewhere, its design differs fromthe typical approaches – and the lessons and results are promising for all OECDcountries.This paper presents the theoretical and practical application of thisalternative approach and as such, the key features of the new Polish pension systemdesign.Introduction Demographic transition together with myopic policies has caused severe problems inthe area of pensions in many countries around the world.Elements of traditionalpension systems’ design include a weak link of benefits to contributions and the lackof control over costs of the system.Inclusion of these elements in the pension systemdesign led to the explosion of costs, caused negative externalities for

growth andcontributed to persistently high unemployment.As such, the quest for pension reformis now on the top of policy agendas around the world, and especially in Europe.However, very few countries have been able to introduce fundamental reforms in thearea of pensions to this time.In this case, the definition of reform is crucial.For thepurposes of this paper, “reform” means changing the system in order to removetructural inefficiencies – and not just playing at the margins with contribution rates and retirement ages to adjust the system’s parameters for short-term fiscal andpolitical reasons.Traditional pension systems have proven to be inefficient in providing societies withsocial security.At the same time attempts to cure these systems are hampered by alack of consensus on what could replace the traditional system.Discussions on thisissue involve confusion stemming from the ideological context of the discussionparticipants, as well as from overuse of such concepts as “pay-as-you-go” versus“funding”, or “public” versus “private”, while at the same time ignoring a number ofimportant economic issues.Furthermore, economists have traditionally ignored pensions.Designing and runningpension systems was left to non-economists, who were not extensively concernedwith how to finance pensions in the long-term or with how to counteract these pensionsystems’ negative externalities.The new Polish pension system belongs to very smallnumber of successful attempts to apply modern thinking in the area of pensions.Thisdoes not mean – as some may assume – giving up social security goals.Rather, thekey idea was to give up the inefficient methods of delivering social security in orderto save its goals and principles.This paper consists of two parts.The first focuses on a discussion of general issuesthat need to be addressed when designing a pension system.These issues arepresented in a way that goes beyond the traditional way of thinking on pensions.In regards to this second part of the paper, it is important to point out that mostcountries in the current EU member states and candidate countries have pensionsystems that are essentially the same at the basic policy level.As such, the solutionsin one member state or candidate country can be expected to be the same.Like European states such as France, Germany, Italy, the Czech Republic, Hungaryand other European states, Poland and Sweden over the past decades and until the late1990’s developed inefficient, costly pension systems.As such, in part two of thepaper we shall examine how Poland has now successfully implemented the approachpresented in the first part of the paper, and created a fundamentally strong and neutralpension system.8

Selected general issues Pension system design has to take into account a number of issues.Their fullpresentation and discussion goes beyond the scope of this paperThis paper presentsonly a list of the issues for consideration and the most important observations.The pension system: externalities versus neutralityThe description of a pension system depends strongly on both the aggregated andindividual viewpoint.From the aggregated perspective, the pension system is a way of dividing currentGDP between a part kept by the working generation and a part allocatedto the retired generation.From the individual perspective, the pension system is a way of income allocationover a person’s life cycle.The above holds irrespective to the technical method applied or the ideologicalviewpoint.The pension system – as defined above – is not necessarily pay-as-you-goor funded.Such features stem from technical elements additionally applied on the topof the pension system, rather than from the system itself.If the pension system designassumes anonymous participation and a substantial scale of redistribution then weusually call this system pay-as-you-go.If the pension system design uses financialmarkets, then we usually call it funded.However, these two typically used concepts do not exhaust all possible combinationsof anonymous versus individualised participation and financial versus non-financialpension system design techniques used.The dualistic pay-as-you-go versus fundedapproach leaves aside the combination of individual participation in a system thatdoes not use financial markets.This approach also neglects the fact that usingfinancial markets means investment(pension portfolio consists of private equities)ordeferring taxes(pension portfolio consists of government bonds), which is obviouslynot the same.Adding redistribution or financial markets to the pension system generatesexternalities.These externalities can be positive and negative.Redistribution withinthe pension system can generate positive externalities if the system is inexpensive,namely the part of GDP allocated to the retired generation is not large.If theredistribution is large, then it generates negative externalities, such as contributing topersistently high unemployment and weak growth.Using financial markets causespositive externalities for growth if the pension system spends contribution money oninvestment.If the contributions are spent on government debt they may lead tonegative externalities similar to those of large redistributive system, namely more taxdistortions.This can happen if the rate of return on government debt is persistentlyabove the rate of GDP growth.There exists yet another option, namely 9

to bring the pension system as close toeconomic neutrality as possible.This option requires, among other things, combiningindividual participation in the system with dividing GDP between generations basedon real economy developments, such as has been done in Poland and Sweden.Demographic structure: consequences of the change.Irrespective of the pension system design technique used, the pension systemexchanges a right of the retired generation for a part of the product of the workinggeneration.The exchange can be organised in various ways and also the rights can beexpressed in various ways.In particular, the rights can be either traded in the financialmarkets, or defined in relation to some economic variables, or just based on politicalpromise.In all of these cases there is a kind of market for pension rights.The workinggeneration finances contributions in order to purchase the rights;the retiredgeneration sells the rights in order to get a part of the product of the workinggeneration.The various types of pension systems create an institutional framework forthis market.Given the contribution rate, the demand side of the market is determined by the number of workers and their productivity.The number of retirees determines the demand side.However, if – as it is the case in traditional systems – pensions are administratively defined in terms of wages(replacement rate promised)then the pension system depends solely on the demographic structure.Even strong productivity growth cannot help in balancing the system’s revenue and expenditure.The general change of the demographic structure we see around the world has caused the pyramid scheme used for financing pension expenditure to no longer generate sufficient revenues.In consequence, previous minor inefficiencies have become devastating.Ageing turned the previous “pyramid-shape” demographic structure into a new “hut-shape” one, as illustrated in Figure 1.10

The pension system strongly depends on the demographic structure of the population.There is no escape from this dependency irrespective of pension system technique used.Using financial markets do not make pension systems immune from this dependency.Financial markets do help, however, in adjusting the system to the current demographic situation by introducing an easy to understand and acceptable link between benefits and contributions paid.The general change of the demographic structure around the world has caused severe fiscal problems for many countries.This change can be seen also from the viewpoint of being able to achieve the traditional social goals of the pension system.In this regard, two important observations are worth mentioning:

In the past, the minority – nowadays the vast majority – of those who pay contributions to the system as workers, afterwards receive benefits as retirees.This means that in the active phase of the individual’s life, participation in the pension system is very similar to long term saving.As the goal is to provide for each individual, using the individual as the main accounting unit becomes a superior way to organize the pension system.In the past, the pension system channelledGDP to the very old people who were unable to earn a living and finance consumption on their own.Nowadays people who retire are still able to work and earn, and they – on average have many years of life left to live.As such, the discussion above shows that the objective of the pension system has changed for the old-age part of the pension system(OA).However, the non-old-age parts of social security systems(NOA), such as disability, remain risk related, irrespective to ageing.This leads to the

conclusion that the various parts of the social security system should be segmented, such that revenues(contributions)and expenses(benefits)can be tied to their purpose exclusively over time, and each segment insulated from each other.In this way, policy makers would be able to look at each segment of the social security system, knowing that its revenues and expenses have been insulated from the risks of other parts of the system and are an accurate reflection of the current state of that segment and together of the system as a whole.The social security system, would then be made of an OA segment(pensions)and various NOA segments(disability, maternity, worker’s compensation, and so forth).This operational and accounting reform is one of the most important non-fiscal reasons for a deep pension reform and would provide policy makers with a powerful tool to understand how well their social security system can and will meet its goals.Pensions: Summary of the proposed approach Typically pension economics, as well as popular discussions, use the following opposing concepts as a central basis for thinking on pensions:

Pay-as-you-go versus funding;

Public versus private;Monopillar versus multipillar.This paper presents an alternative approach.This alternative approach can be summarised in the following four pairs of opposing concepts:

Universal(mandatory covering the entire population)versus partial(voluntary participation of a group of people);

Individualised(individual accounts)versus anonymous(no accounts)participation;

Task specific/segmented(OA separated from NOA)versus multitask(OA and NOA mixed within one scheme)organisation of social security;

Financial(generating the rate of return through financial markets)versus nonfinancial(generating the rate of return through real economy growth).The efficient pension system is designed in a way that makes it endogenous, which means it adjusts automatically without intervening from outside.The system needs only one decision, namely the initial choice of the contribution rate.The way of thinking on pensions based on the above set of comparisons can be useful for better

describing and analysing the pension system.This approach can also let the discussion on pensions go beyond the hopeless controversy of those who promote private funded pension funds and those who promote what is called the pay-as-you-go system.As such policy makers in the European Union and elsewhere could benefit using the proposed methodology when looking at reforming their pension systems.Key features of the new Polish pension system The new Polish pension system design is a good example of applying the abovedescribed way of thinking in practice.The system named “Security throughDiversity” started on 1 January 1999.It entirely replaced previous regulations on oldagepensions for majority of working population.Designing the new system fromscratch provided the unique opportunity to avoid complicating the system.Instead, thenew system design is simple and transparent.The main goal was to design a systemthat can be neutral or at least close to neutrality for economic growth irrespective ofpopulation ageing.The design of the new system does not copy any other pension system existingelsewhere.Strong similarity can be found only to the new Swedish pension systembased on similar principles and started on the same day.16 At the same time, withinthis general framework the new Polish system uses a number of technical conceptsdeveloped in other countries.This brief presentation of the new Polish pension systemfocuses on the general economic design of the system, while leaving aside mosttechnical details.The following bullets help in grasping the essence of the concept of the new Polishsystem design.Focusing on the universal part of the pension system;Separation of the old-age part of social security from the non-old-age parts ofsocial security;and segmenting the flows of revenue;Termination of the part of the previous system;Creation of a new pension system, entirely based on individual accounts;Accrual accounting within the system;Splitting each person’s OA contributions between two accounts(first account – NDC, second account – FDC);Annuitisation of account values at the moment ofretirement;Minimum pension supplement on the top of both annuities if their sum is below certain level(financed out of the state budget).It should be strongly stressed that both accounts are annuitised at the same momentand play exactly the same role within social security.In particular there is no suchelement of the system as a “basic state pension”.Social redistribution exists but it hasbeen moved out from the pension system.The sole role of the pension system isproviding working generation with an efficient method of income allocation over theirlife cycle.The contribution rate for the entire social security system has not changed.Howeverworkers’ salaries were “grossed up” in order to introduce to them the idea that theypay part of the contribution and to build their awareness of the overall cost of thepension system.As such, since 1 January 1999 both workers and employers share thecost of contributions without any real change in the size of the total contributions.Thewhole operation affected percentages but not real flows of money.Thus the newsystem is based on the same contribution inflow as the previous system.Final remarks Providing people with social security – including financing consumption of the retiredgeneration out of the product of the working generation-is very high on the list of social priorities in most countries.It is especially important in European societies.However, the inefficiency of traditional pension systems put achieving this goal atrisk.Social and populist rhetoric suggests to the public that changes within thepension system are dangerous for social goals.In reality, for most countries in theworld, it is just the opposite.The longer the traditional pension systems are held up,the more socially damaging effects will be created.Poland belongs to a non-numerous group of countries that are prepared for one of themost difficult challenges of our time, namely the ageing of the population.The newpension system will not only stop the increase of costs of the pension system but willalso allow for their reduction.This will leave more resources available fordevelopment, which, in turn, will contribute to stronger growth and the increase ofliving standards of both the working and the retired generation.The example of the new Polish pension system, as well as the Swedish one, isinteresting for yet another reason.This type of system contributes to labour mobility,which is particularly needed in Europe.Free movement of labour cannot be achievedif moving from one country to another affects expected retirement income.As such,aiming at pension system neutrality will be more and more important for Europeanintegration.

第二篇：外文翻譯

當(dāng)今時(shí)代是一個(gè)自動(dòng)化時(shí)代，交通燈控制等很多行業(yè)的設(shè)備都與計(jì)算機(jī)密切相關(guān)。因此，一個(gè)好的交通燈控制系統(tǒng)，將給道路擁擠，違章控制等方面給予技術(shù)革新。隨著大規(guī)模集成電路及計(jì)算機(jī)技術(shù)的迅速發(fā)展，以及人工智能在控制技術(shù)方面的廣泛運(yùn)用，智能設(shè)備有了很大的發(fā)展，是現(xiàn)代科技發(fā)展的主流方向。本文介紹了一個(gè)智能交通的系統(tǒng)的設(shè)計(jì)。該智能交通燈控制系統(tǒng)可以實(shí)現(xiàn)的功能有：對(duì)某市區(qū)的四個(gè)主要交通路口進(jìn)行控制：個(gè)路口有固定的工作周期，并且在道路擁擠時(shí)中控制中心能改變其周期：對(duì)路口違章的機(jī)動(dòng)車能夠即時(shí)拍照，并提取車牌號(hào)。在世界范圍內(nèi)，一個(gè)以微電子技術(shù)，計(jì)算機(jī)和通信技術(shù)為先導(dǎo)的，一信息技術(shù)和信息產(chǎn)業(yè)為中心的信息革命方興未艾。而計(jì)算機(jī)技術(shù)怎樣 與實(shí)際應(yīng)用更有效的結(jié)合并有效的發(fā)揮其作用是科學(xué)界最熱門的話題，也是當(dāng)今計(jì)算機(jī)應(yīng)用中空前活躍的領(lǐng)域。本文主要從單片機(jī)的應(yīng)用上來實(shí)現(xiàn)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(yùn)作。

研究交通的目的是為了優(yōu)化運(yùn)輸，人流以及貨流。由于道路使用者的不斷增加，現(xiàn)有資源和基礎(chǔ)設(shè)施有限，智能交通控制將成為一個(gè)非常重要的課題。但是，智能交通控制的應(yīng)用還存在局限性。例如避免交通擁堵被認(rèn)為是對(duì)環(huán)境和經(jīng)濟(jì)都有利的，但改善交通流也可能導(dǎo)致需求增加。交通仿真有幾個(gè)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(dú)車輛的行為，從而模仿動(dòng)態(tài)的車輛組。

由于低效率的交通控制，汽車在城市交通中都經(jīng)歷過長(zhǎng)時(shí)間的行進(jìn)。采用先進(jìn)的傳感器和智能優(yōu)化算法來優(yōu)化交通燈控制系統(tǒng)，將會(huì)是非常有益的。優(yōu)化交通燈開關(guān)，增加道路容量和流量，可以防止交通堵塞，交通信號(hào)燈控制是一個(gè)復(fù)雜的優(yōu)化問題和幾種智能算法的融合，如模糊邏輯，進(jìn)化算法，和聚類算法已經(jīng)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(hào)燈。

在我們的方法中，聚類算法與道路使用者的價(jià)值函數(shù)是用來確定每個(gè)交通燈的最優(yōu)決策的，這項(xiàng)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(jì)每輛車的好處(或收益)來確定綠燈時(shí)間增益值與總時(shí)間是有差異的，它希望在它往返的時(shí)候等待，如果燈是紅色，或者燈是綠色。等待，直到車輛到達(dá)目的地，通過有聚類算法的基礎(chǔ)設(shè)施，最后經(jīng)過監(jiān)測(cè)車的監(jiān)測(cè)。

我們對(duì)自己的聚類算法模型和其它使用綠燈模擬器的系統(tǒng)做了比較。綠燈模擬器是一個(gè)交通模擬器，監(jiān)控交通流量統(tǒng)計(jì)，如平均等待時(shí)間，并測(cè)試不同的交通燈控制器。結(jié)果表明，在擁擠的交通條件下，聚類控制器性能優(yōu)于其它所有測(cè)試的非自適應(yīng)控制器，我們也測(cè)試?yán)碚撋系钠骄却龝r(shí)間，用以選擇車輛通過市區(qū)的道路，并表明，道路使用者采用合作學(xué)習(xí)的方法可避免交通瓶頸。

本文安排如下：第2部分?jǐn)⑹鋈绾谓⒔煌Ｐ停A(yù)測(cè)交通情況和控制交通。第3部分是就相關(guān)問題得出結(jié)論。第4部分說明了現(xiàn)在正在進(jìn)一步研究的事實(shí)，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(shè)計(jì)一個(gè)位于十字路口的智能交通燈控制系統(tǒng)

摘要：本文模型使用模糊本體的交通燈控制域，并把它應(yīng)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(gè)獨(dú)立的可重復(fù)使用的交通燈控制模塊。通過這種方式，增加軟件的獨(dú)立性和為其他的軟件開發(fā)活動(dòng)如測(cè)試和維護(hù)，提供了便利。專家對(duì)本體論進(jìn)行手動(dòng)的開發(fā)和評(píng)估。此外，交通數(shù)據(jù)提取和分類路口使用的人工神經(jīng)網(wǎng)絡(luò)的圖像處理算法。根據(jù)預(yù)定義的XML架構(gòu)，這種信息轉(zhuǎn)化為XML實(shí)例映射到適合使用模糊推理引擎的模糊規(guī)則的模糊本體。把本系統(tǒng)的性能與其他類似的系統(tǒng)性能進(jìn)行比較。比較結(jié)果顯示：在所有的交通條件下，在每個(gè)周期中，對(duì)每輛車它有低得多的平均延遲時(shí)間與其他的控制系統(tǒng)相比。

關(guān)鍵詞:模糊本體,智能代理,智能交通系統(tǒng)(ITS),交通信號(hào)燈控制(TLC),孤立的十字路口,圖像處理,人工神經(jīng)網(wǎng)絡(luò)

1.引言

作為城市交通增加的結(jié)果,道路網(wǎng)絡(luò)的能力有限和發(fā)展交通工具和方法的技術(shù)方面，許多實(shí)體，關(guān)系，情況和規(guī)則已經(jīng)進(jìn)入交通燈控制域和轉(zhuǎn)化成為一個(gè)知識(shí)領(lǐng)域。這個(gè)領(lǐng)域的建模知識(shí)幫助交通代理和應(yīng)用有效地管理關(guān)于實(shí)時(shí)條件下的交通。全面知識(shí)建模領(lǐng)域的一個(gè)最合適的方法是使用本體概念。“本體論是一個(gè)正式的、明確的一個(gè)共享的概念化的規(guī)范。以前的模型是基本的本體建設(shè)的基礎(chǔ)，為下列建立一個(gè)共享的語義豐富的知識(shí)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(shù)據(jù)。這種能力將提高有關(guān)性能的決定和其他非智能系統(tǒng)的功能特點(diǎn)。在近年來，本體論上的研究正成為一個(gè)新的熱點(diǎn)話題在不同的活動(dòng)，如人工智能，知識(shí)管理，語義網(wǎng)絡(luò)，電子商務(wù)和幾個(gè)其他應(yīng)用領(lǐng)域。這些領(lǐng)域之一是智能交通系統(tǒng)。一些努力已制成這個(gè)通過展示和使用本體檢測(cè)交通領(lǐng)域擁塞，管理非城市道路氣象事件，駕駛阿德?！骼锵到y(tǒng)，共享和整合一個(gè)智能交通系統(tǒng)。本文的目的是介紹一個(gè)紅綠燈有效控制孤立交叉口這方面的知識(shí)重用的控制本體。這種新的辦法適用于智能代理使用知識(shí)決策模糊。該系統(tǒng)采用的圖像來自安裝了監(jiān)控?cái)z像機(jī)拍攝的路口。這些圖像處理利用圖像處理算法和神經(jīng)網(wǎng)絡(luò)的方法，然后發(fā)送到一個(gè)智能代理。第2節(jié)中，我們將簡(jiǎn)要地解釋了在這項(xiàng)工作中運(yùn)用的技術(shù)包括seman-TIC網(wǎng)絡(luò)技術(shù)，智能代理技術(shù)和交通的回地面光控制方法。在第3節(jié)，新的系統(tǒng)架構(gòu)是基于分層語義網(wǎng)絡(luò)架構(gòu)。第4節(jié)介紹交通燈控制的模糊本體的建設(shè)。第五節(jié)從路口提取的圖像信息解釋。在第6節(jié)，智能系統(tǒng)的運(yùn)作被完整描述，最后在第7節(jié)對(duì)所提出的方法進(jìn)行評(píng)估，對(duì)結(jié)論進(jìn)行闡述。

2.背景

本節(jié)說明在這項(xiàng)工作中的應(yīng)用技術(shù)包括語義網(wǎng)絡(luò)技術(shù)，特別本體和模糊本體。此外，國(guó)家的交通燈控制的藝術(shù)方法是簡(jiǎn)要介紹。2.1.語義網(wǎng)絡(luò)技術(shù)

語義網(wǎng)絡(luò)被定義為當(dāng)前Wed的延伸，這些網(wǎng)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(guī)則如表1所示。圖.4顯示輸出模式的示意圖。本次評(píng)選有助于智能系統(tǒng)，以確定下一步的階段測(cè)序。

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

例如一個(gè)階段選型的模糊規(guī)則如下所述：“如果一個(gè)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(jiǎn)單的兩階段”。此外，為周期時(shí)間估計(jì)的模糊規(guī)則表示如下：“如果天氣條件是晴天，時(shí)間是早晨，天是正常的，平均車輛擁堵是低，則周期時(shí)間短”。在此類別中的所有規(guī)則都列在附錄A。

在此步驟結(jié)束時(shí)，應(yīng)該對(duì)交通燈邏輯控制的項(xiàng)目的有效性進(jìn)行評(píng)估。此功能是使用專家的意見。評(píng)價(jià)過程的主要目的是顯示發(fā)展的本體和其相關(guān)的軟件環(huán)境的用處。雖然所有的信息，尤其是交通燈控制規(guī)則已提取國(guó)際標(biāo)準(zhǔn)和科學(xué)交通文學(xué)，專家的知識(shí)優(yōu)勢(shì)是他們最后的正確性驗(yàn)證標(biāo)準(zhǔn)。所有模糊規(guī)則，包括優(yōu)化周期時(shí)間和相位類型的規(guī)則，在這個(gè)過程中，準(zhǔn)備以調(diào)查問卷形式和展現(xiàn)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(guī)則和優(yōu)化周期時(shí)間的87％被接受。此外，所有交通邏輯控制的元素包括概念，關(guān)系，屬性和公理都被這些專家進(jìn)行了評(píng)估和驗(yàn)證。我們?cè)u(píng)估邏輯交通控制是基于理論知識(shí)的。在這個(gè)過程中進(jìn)行了兩項(xiàng)活動(dòng)，包括檢查的要求和能力的問題，并在目標(biāo)應(yīng)用環(huán)境測(cè)試本體。由于邏輯交通控制已建成的基礎(chǔ)上，如指定要求優(yōu)化循環(huán)時(shí)間，逐步淘汰型，交通的移動(dòng)和優(yōu)化綠燈時(shí)間，每個(gè)階段的序列中，第一項(xiàng)活動(dòng)是最好的結(jié)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(jī)效評(píng)估機(jī)制，可以支持這種說法。在部分實(shí)驗(yàn)結(jié)果我們驗(yàn)證了這一過程。

第四篇：外文翻譯

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

超聲測(cè)距系統(tǒng)設(shè)計(jì)

原文出處：傳感器文摘 布拉福德：1993年第13頁(yè)

摘要：超聲測(cè)距系統(tǒng)技校在工業(yè)場(chǎng)車輛導(dǎo)航水聲工程等領(lǐng)域都具有了廣泛的應(yīng)用價(jià)值，目前已應(yīng)用于物理測(cè)量，機(jī)器人自動(dòng)導(dǎo)航以及空氣中與水下的目標(biāo)探測(cè)、識(shí)別定位等場(chǎng)合，因此，深入研究超聲的探測(cè)理論和方法具有重要的實(shí)踐意義，為了進(jìn)一步提高測(cè)量的精確度，滿足工程人員對(duì)測(cè)量精度測(cè)距量程和測(cè)距儀使用的要求，本文研制了一套基于單片機(jī)的使拱式超聲測(cè)距系統(tǒng)。關(guān)鍵詞：超聲波 測(cè)距儀 單片機(jī)

1、前言

隨著科技的發(fā)展，人們生活水平的提高，城市發(fā)展建設(shè)加快，城市給排水系統(tǒng)也有較大發(fā)展，其狀況不斷改善，但是，由于歷史原因合成時(shí)間性的許多不可預(yù)見因素，城市給排水系統(tǒng)，特別是排水系統(tǒng)往往落后于城市建設(shè)，因此，經(jīng)常出現(xiàn)開挖已經(jīng)建設(shè)好的建筑設(shè)施來改造排水系統(tǒng)的現(xiàn)象。城市污水給人們帶來的困擾，因此箱的排污疏通對(duì)大城市給排水系統(tǒng)污水理，人們生活舒適顯得非常重要。而設(shè)計(jì)研制箱涵排水疏通移動(dòng)機(jī)器人的自動(dòng)控制系統(tǒng)，保證機(jī)器人在箱涵中自由排污疏通，是箱涵排水系統(tǒng)疏通機(jī)器人的設(shè)計(jì)研制的核心部分，控制系統(tǒng)核心部分就是超聲波測(cè)儀的研制。因此，設(shè)計(jì)好的超聲波測(cè)距儀就顯得非常重要了。

1.1課題背景

隨著經(jīng)濟(jì)的發(fā)展與汽車科學(xué)技術(shù)的進(jìn)步，公路交通呈現(xiàn)出行駛高速化、車流密集化和駕駛員非職業(yè)化的趨勢(shì)。同時(shí)，隨著汽車工業(yè)的飛速發(fā)展，汽車的產(chǎn)量和保有量都在急劇增加。但公路發(fā)展、交通管理卻相對(duì)落后，導(dǎo)致了交通事故與日劇增，城市里尤其突出。智能交通系統(tǒng)ITS是目前世界上交通運(yùn)輸科學(xué)技術(shù)的前沿技術(shù)，它在充分發(fā)揮現(xiàn)有基礎(chǔ)設(shè)施的潛力，提高運(yùn)輸效率，保障交通安全，緩解交通賭塞，改善城市環(huán)境等方面的卓越效能，已得到各國(guó)政府的廣泛關(guān)注。中國(guó)政府也高度重視智能交通系統(tǒng)的研究開發(fā)與推廣應(yīng)用。汽車防撞系統(tǒng)作為ITS 發(fā)展的一個(gè)基礎(chǔ)，它的成功與否對(duì)整個(gè)系統(tǒng)有著很大的作用。從傳統(tǒng)上說，汽車的安全可以分為兩個(gè)主要研究方向:一是主動(dòng)式安全技術(shù)，即防止事故的發(fā)生，該種方式是目前汽車安全研究的最終目的;二是被動(dòng)式安全技術(shù)，即事故發(fā)生后的乘員保護(hù)。目前汽車安全領(lǐng)域被動(dòng)安全研究較多，主要從安全氣囊、ABS(防抱死系統(tǒng))和懸架等方面著手，以保證駕乘人員的安全。從經(jīng)濟(jì)性和安全性兩方面來說，中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

這些被動(dòng)安全措施是在事故發(fā)生時(shí)刻對(duì)車輛和人員進(jìn)行保護(hù)，有很大的局限性，因而車輛的主動(dòng)安全研究尤為重要，引出了本文研究的基于單片機(jī)的超聲波測(cè)距系統(tǒng)。這個(gè)系統(tǒng)是一種可向司機(jī)預(yù)先發(fā)出視聽語音信號(hào)的探測(cè)裝置。它安裝在汽車上，能探測(cè)企圖接近車身的行人、車輛或周圍障礙物;能向司機(jī)及乘員提前發(fā)出即將發(fā)生撞車危險(xiǎn)的信號(hào)，促使司機(jī)采取應(yīng)急措施來應(yīng)付特殊險(xiǎn)情，避免損失。

1.2 課題設(shè)計(jì)的意義

隨著現(xiàn)代社會(huì)工業(yè)化程的發(fā)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(fā)生，由此導(dǎo)致的人員傷亡和財(cái)產(chǎn)損失數(shù)目驚人。對(duì)于公路交通事故的分析表明，80%以上的車禍?zhǔn)掠捎隈{駛員反應(yīng)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(cè)面相撞。奔馳汽車公司對(duì)各類交通事故的研究表明：若駕駛員能夠提早1S 意識(shí)到有事故危險(xiǎn)并采取相應(yīng)的正確措施，則絕大多數(shù)的交通事故都可以避免。因此，大力研究開發(fā)如汽車防撞裝置等主動(dòng)式汽車輔助安全裝置，減少駕駛員的負(fù)擔(dān)和判斷錯(cuò)誤，對(duì)于提高交通安全將起到重要的作用。顯然，此類產(chǎn)品的研究開發(fā)具有極大的實(shí)現(xiàn)意義和廣闊的應(yīng)用前景。

1.3超聲波測(cè)距在汽車上應(yīng)用的介紹

超聲波倒車測(cè)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(shù)字形式動(dòng)態(tài)顯示周圍障礙物的情況。其較早的產(chǎn)品是用蜂鳴器報(bào)警，蜂鳴聲越急，表示車輛離障礙物越近。后繼的產(chǎn)品可以顯示車后障礙物離車體的距離。其大多數(shù)產(chǎn)品探測(cè)范圍在0.4～1.5m，有的產(chǎn)品能達(dá)到0.35～2.5m，并有距離顯示、聲響報(bào)警、區(qū)域警示和方位指示，有些產(chǎn)品還具備開機(jī)自檢功能。目前市場(chǎng)上還出現(xiàn)了具有語音報(bào)警功能的產(chǎn)品。這些產(chǎn)品存在的主要問題是測(cè)量盲區(qū)大，報(bào)警滯后，未考慮汽車制動(dòng)時(shí)的慣性因素，使駕駛者制動(dòng)滯后，抗干擾能力不強(qiáng)，誤報(bào)也較多。汽車防撞雷達(dá)之所以能實(shí)現(xiàn)防撞報(bào)警功能，主要有超聲波這把無形尺子, 它測(cè)量最近障礙物的距離, 并告訴給車主。其實(shí)超聲測(cè)距原理簡(jiǎn)單: 它發(fā)射超聲波并接收反射回波, 通過單片機(jī)計(jì)數(shù)器獲得兩者時(shí)間差t, 利用公式S=Ct/2計(jì)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(zhì)中的傳播速度。

本文介紹的超聲測(cè)距系統(tǒng)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(gè)位置上。能檢測(cè)前進(jìn)和倒車方向障礙物距離, 通過后視鏡內(nèi)置的

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

顯示單元顯示距離和方位, 發(fā)出一定的聲響, 起到提示和警戒的作用。系統(tǒng)采用一片STC89C52單片機(jī)對(duì)兩路超聲波信號(hào)進(jìn)行循環(huán)采集。超聲波是指頻率高于20HHZ的機(jī)械波。為了以超聲波作為檢測(cè)手段，必須產(chǎn)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(xí)慣上稱為超聲波換能器或超聲波探頭。超聲波傳感器有發(fā)送器和接收器，但一個(gè)超聲波傳感器也可具有發(fā)送和接收聲波的雙重作用。超聲波傳感器是利用壓電效應(yīng)的原理將電能和超聲波相互轉(zhuǎn)化，即在發(fā)射超聲波的時(shí)候，將電能轉(zhuǎn)換，發(fā)射超聲波；而在收到回波的時(shí)候，則將超聲振動(dòng)轉(zhuǎn)換成電信號(hào)。超聲波測(cè)距的原理一般采用渡越時(shí)間法。首先測(cè)出超聲波從發(fā)射到遇到障礙物返回所經(jīng)歷的時(shí)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(cè)量距離的方法有很多種，短距離的可以用尺，遠(yuǎn)距離的有激光測(cè)距等，超聲波測(cè)距適用于高精度的中長(zhǎng)距離測(cè)量。因?yàn)槌暡ㄔ跇?biāo)準(zhǔn)空氣中的傳播速度為331.45米/秒，由單片機(jī)負(fù)責(zé)計(jì)時(shí)，單片機(jī)使用12.0M晶振，所以此系統(tǒng)的測(cè)量精度理論上可以達(dá)到毫米級(jí)。由于超聲波指向性強(qiáng)，能量消耗緩慢，在介質(zhì)中傳播距離遠(yuǎn)，因而超聲波可以用于距離的測(cè)量。利用超聲波檢測(cè)距離，設(shè)計(jì)比較方便，計(jì)算處理也較簡(jiǎn)單，并且在測(cè)量精度方面也能達(dá)到要求。超聲波發(fā)生器可以分為兩類：一類是用電氣方式產(chǎn)生超聲波，一類是用機(jī)械方式產(chǎn)生超聲波。本設(shè)計(jì)屬于近距離測(cè)量，可以采用常用的壓電式超聲波換能器來實(shí)現(xiàn)觸發(fā)單元。

利用超聲波測(cè)距的工作，就可以根據(jù)測(cè)量發(fā)射波與反射波之間的時(shí)間間隔，從而達(dá)到測(cè)量距離的作用。其主要有三種測(cè)距方法：

（1）相位檢測(cè)法，相位檢測(cè)法雖然精度高，但檢測(cè)范圍有限；

（2）聲波幅值檢測(cè)法，聲波幅值檢測(cè)法易受反射波的影響；

（3）渡越時(shí)間檢測(cè)法，渡越時(shí)間檢測(cè)法的工作方式簡(jiǎn)單，直觀，在硬件控制和軟件設(shè)計(jì)上都非常容易實(shí)現(xiàn)。其原理為：檢測(cè)從發(fā)射傳感器發(fā)射超聲波，經(jīng)氣體介質(zhì)傳播到接收傳感器的時(shí)間，這個(gè)時(shí)間就是渡越時(shí)間。本設(shè)計(jì)的超聲波測(cè)距就是使用了渡越時(shí)間檢測(cè)法。在移動(dòng)車輛中應(yīng)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(fā)射的超聲波反射信號(hào)，根據(jù)超聲波發(fā)出及回波接收的時(shí)間差和傳播速度，計(jì)算傳播距離，從而得到障礙物到車輛的距離。

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文 超聲波測(cè)距原理

2.1 壓電式超聲波發(fā)生器原理

壓電式超聲波發(fā)生器實(shí)際上是利用壓電晶體的諧振來工作的。超聲波發(fā)生器內(nèi)部結(jié)構(gòu)，它有兩個(gè)壓電晶片和一個(gè)共振板。當(dāng)它的兩極外加脈沖信號(hào)，其頻率等于壓電晶片的固有振蕩頻率時(shí)，壓電晶片將會(huì)發(fā)生共振，并帶動(dòng)共振板振動(dòng)，便產(chǎn)生超聲波。反之，如果兩極板間未加電壓，當(dāng)共振板接收到超聲波時(shí)，將壓迫壓電晶片做振動(dòng)，將機(jī)械能轉(zhuǎn)換為電信號(hào)，這是它就成為超聲波接收器了。

測(cè)量脈沖到達(dá)時(shí)間的傳統(tǒng)方法是以擁有固定參數(shù)的接收信號(hào)開端為基礎(chǔ)的。這個(gè)信號(hào)恰恰選于噪音水平之上，然而脈沖到達(dá)時(shí)間被定義為脈沖信號(hào)剛好超過界限的第一時(shí)刻。一個(gè)物體的脈沖強(qiáng)度很大程度上取決于這個(gè)物體的自然屬性尺寸還有它與傳感器的距離。進(jìn)一步說，從脈沖起始點(diǎn)到剛好超過界限之間的時(shí)間段隨著脈沖的強(qiáng)度而改變。結(jié)果，一種錯(cuò)誤便出現(xiàn)了——兩個(gè)擁有不同強(qiáng)度的脈沖在不同時(shí)間超過界限卻在同一時(shí)刻到達(dá)。強(qiáng)度較強(qiáng)的脈沖會(huì)比強(qiáng)度較弱的脈沖超過界限的時(shí)間早點(diǎn)，因此我們會(huì)認(rèn)為強(qiáng)度較強(qiáng)的脈沖屬于較近的物體。

2.2 超聲波測(cè)距原理

超聲波發(fā)射器向某一方向發(fā)射超聲波，在發(fā)射時(shí)刻的同時(shí)開始計(jì)時(shí)，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(jì)時(shí)。超聲波在空氣中的傳播速度為340m/s，根據(jù)計(jì)時(shí)器記錄的時(shí)間t，就可以計(jì)算出發(fā)射點(diǎn)距離障礙物的距離(s)，即：s=340t/2

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3、超聲波測(cè)距系統(tǒng)的電路設(shè)計(jì)

系統(tǒng)的特點(diǎn)是利用單片機(jī)控制超聲波的發(fā)射和超聲波自發(fā)射至接受往返時(shí)間的計(jì)時(shí)，單片機(jī)選用C51，經(jīng)濟(jì)易用，且片內(nèi)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

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3.1 40kHz脈沖的產(chǎn)生與超聲波發(fā)射

測(cè)距系統(tǒng)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(hào)，這由單片機(jī)執(zhí)行下面的程序來產(chǎn)生。puzel：mov 14h，#12h

here： cp1.0；

nop；

nop；

nop；

djnz 14h，here；

Ret

前方測(cè)距電路的輸出端接單片機(jī)P1.0端口，單片機(jī)執(zhí)行上面的程序后，在P1.0端口輸出一個(gè)40khz的脈沖信號(hào)，經(jīng)過三極管T放大，驅(qū)動(dòng)超聲波發(fā)射頭UCM40T，發(fā)出40khz的脈沖超聲波，且持續(xù)發(fā)射200ms。右側(cè)合作側(cè)測(cè)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(cè)距電路相同。

超聲波發(fā)射持續(xù)200ms 輸出40kHz方波

3.2 超聲波的接收與處理

接收頭采用與發(fā)射頭配對(duì)的UCM40R，將超聲波調(diào)制脈沖變?yōu)殡妷盒盘?hào)，經(jīng)運(yùn)算放大器ic1a和ic1b兩級(jí)放大后加至IC2,。IC2是帶有鎖定環(huán)的音頻譯碼集成塊LM567，內(nèi)部壓控振蕩器的中心頻率f0=1/1.1R8C3，電容C4決定其帶寬。調(diào)節(jié)R8在發(fā)射的載頻上，則LM567輸入信號(hào)大于25mv，輸出端8腳由5由高電平躍變?yōu)榈碗娖剑鳛橹袛嗾?qǐng)求信號(hào)，送至單片機(jī)處理。

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

push acc

clr ex1；關(guān)中斷源1

jnb p1.1，right;P1.1引腳為0，轉(zhuǎn)至右側(cè)距電路中斷服務(wù)程序

jnb p1.2,left;P1.2 引腳為0，轉(zhuǎn)至左測(cè)距中斷電路服務(wù)程序 returne：SETB EX1；

開外部中斷1

pop acc

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pop psw

reti right：

...；

右測(cè)距電路中斷服務(wù)程序入口

ajmp return

left：

...；

左測(cè)距電路中斷服務(wù)程序入口

ajmp return

3.3 計(jì)算超聲波傳播時(shí)間

在啟動(dòng)發(fā)射電路的同時(shí)啟動(dòng)單片機(jī)內(nèi)部的定時(shí)器T0，利用定時(shí)器的計(jì)數(shù)功能，記錄超聲波發(fā)射的時(shí)間和受到反射波的時(shí)間。當(dāng)收到超聲波反射波時(shí)，接受電路輸出端產(chǎn)生一個(gè)負(fù)跳變，在INT0或INT1端產(chǎn)生一個(gè)中斷請(qǐng)求信號(hào)，單片機(jī)響應(yīng)外部中斷請(qǐng)求，執(zhí)行外部中斷服務(wù)子程序，讀取時(shí)間差，計(jì)算距離。其部分源程序如下：

RECEIVEO: PUSH PSW

PUSH ACC CLR EX0;

關(guān)外部中斷0 讀取時(shí)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(duì)于一個(gè)平坦的目標(biāo)，測(cè)量距離包括兩個(gè)階段：粗糙的測(cè)量和精細(xì)的測(cè)量。第一步：脈沖的傳送產(chǎn)生一種簡(jiǎn)單的超聲波

第二步：根據(jù)公式改變回波放大器的獲得量直到回?fù)鼙粰z測(cè)到。第三步：檢測(cè)兩種回波的振幅與過零時(shí)間。

計(jì)算時(shí)間值 存儲(chǔ)結(jié)果

開外部中斷0

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第四步：設(shè)置回波放大器的所得規(guī)格輸出，假定是3v。通過脈沖的周期設(shè)置下一個(gè)脈沖。根據(jù)第二部的數(shù)據(jù)設(shè)定時(shí)間窗。

第五步：發(fā)射兩竄脈沖產(chǎn)生干擾波。測(cè)量過零時(shí)間與回波振幅。如果逆向發(fā)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(jì)算距離y。

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4、超聲波測(cè)距系統(tǒng)的軟件設(shè)計(jì)

軟件分為倆部分，主程序和中斷服務(wù)程序。主程序完成初始化工作、各路超聲波發(fā)射和接收順序的控制。定時(shí)中斷服務(wù)子程序完成三方向超聲波的輪流發(fā)射，外部中斷服務(wù)子程序主要完成時(shí)間值的讀取、距離計(jì)算、結(jié)果的輸出等工作。

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5、結(jié)論

對(duì)所要求測(cè)量范圍30cm-200cm內(nèi)的平面物體做了多次測(cè)量發(fā)現(xiàn)，其最大誤差為1.5cm，且重復(fù)性好。可見基于單片機(jī)設(shè)計(jì)的超聲波測(cè)距系統(tǒng)具有硬件結(jié)構(gòu)簡(jiǎn)單、工作可靠、測(cè)量誤差小等特點(diǎn)。因此，它不僅可用于移動(dòng)機(jī)器人，還可以用在其他檢測(cè)系統(tǒng)中。

思考：至于為什么不用接收管做放大電路，因?yàn)榉糯蟊稊?shù)搞不好，集成放大電路，還帶自動(dòng)電平增益控制，放大倍數(shù)為76db，中心頻率是38k到40k，剛好是超聲波傳感器的諧振頻率。

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參考文獻(xiàn)

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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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

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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

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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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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(xué)院畢業(yè)設(shè)計(jì)（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://004km.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,