第一篇：外文翻譯1

近代電力電子電力傳動(dòng)的進(jìn)步與前景

摘要—電力電子技術(shù)在過(guò)去的四十年里經(jīng)歷了動(dòng)態(tài)演變。最近由于成本的減少，大小和性能的改進(jìn)，它的應(yīng)用在工業(yè)、住宅、交通、公用事業(yè)、航天和軍事環(huán)境領(lǐng)域迅速擴(kuò)張。在第二十一世紀(jì)全球工業(yè)自動(dòng)化，節(jié)約能源，和環(huán)境污染控制的發(fā)展趨勢(shì)，電力電子技術(shù)的廣泛影響是不可取代的?？磥?lái)，在未來(lái)電力電子技術(shù)的作用就像今天信息技術(shù)對(duì)我們的社會(huì)一樣重要和普遍。在本文中，先對(duì)電力電力技術(shù)的歷史作一個(gè)簡(jiǎn)要的介紹然后討論電力電子技術(shù)的重要性。然后是功率半導(dǎo)體器件，轉(zhuǎn)換器，交流變頻驅(qū)動(dòng)器的最新進(jìn)展，以及先進(jìn)的控制和估計(jì)技術(shù)將簡(jiǎn)要評(píng)估。不同于傳統(tǒng)的技術(shù)調(diào)查文件，本文內(nèi)一些數(shù)字被刻意保持小于文本約束長(zhǎng)度。不同地區(qū)的預(yù)報(bào)將盡可能根據(jù)作者自己的知識(shí)和經(jīng)驗(yàn)被突出?？偨Y(jié)和展望未來(lái)，電力電子和電力傳動(dòng)將沿著一些可能的研究和發(fā)展領(lǐng)域的趨勢(shì)被突出。關(guān)鍵詞——控制，變頻器，電機(jī)，電力電子。1.前言

在模式功率半導(dǎo)體開(kāi)關(guān)器件的幫助下，電力電子技術(shù)可以處理在毫瓦到千兆瓦廣闊范圍內(nèi)電力電子轉(zhuǎn)換和控制。電力電子的應(yīng)用可能包括直流和交流電源、無(wú)間斷電源(UPS)系統(tǒng)、電化學(xué)過(guò)程(如電鍍、電解、氧化和金屬精煉)、取暖和照明控制、電子焊接、電力線路靜態(tài)無(wú)功補(bǔ)償器(靜態(tài)無(wú)功補(bǔ)償、靜態(tài)無(wú)功發(fā)生器或靜態(tài)同步補(bǔ)償器(STATCOM)),有源諧波濾波器,高壓直流(HVDC)系統(tǒng)、光伏(PV)和燃料電池(FC)能量轉(zhuǎn)化,固態(tài)直流和交流斷路器,高頻加熱、電機(jī)驅(qū)動(dòng)器。電機(jī)驅(qū)動(dòng)器區(qū)域可能包括應(yīng)用程序在計(jì)算機(jī)和外圍設(shè)備,固態(tài)初學(xué)者對(duì)汽車運(yùn)輸(電動(dòng)/混合動(dòng)力電動(dòng)汽車(EV /HEV)、地鐵等)、家用電器、紙和紡織廠,風(fēng)力發(fā)電系統(tǒng), 空調(diào)和熱泵、滾動(dòng)和水泥工廠、機(jī)床和機(jī)器人，泵和壓縮機(jī)、船舶推進(jìn)等。除了應(yīng)用在能源系統(tǒng)和工業(yè)自動(dòng)化，在全球節(jié)能形式下電力電子正在扮演一個(gè)間接幫助的環(huán)境污染控制重要的角色,即解決全球變暖問(wèn)題。

讓我們先回頭看看電力電子的歷史演進(jìn),如圖1所示。官網(wǎng)認(rèn)為，,電力電子誕生于1901年由美國(guó)的彼得·庫(kù)珀休伊特發(fā)明的燈泡汞弧整流器。然后,它經(jīng)歷了1930年代氣體管電子時(shí)代在和1940年代的飽和鐵芯磁放大器。目前固態(tài)電力電子的時(shí)代已經(jīng)開(kāi)始介紹晶閘管或者可控硅(SCR)。1956年美國(guó)貝爾實(shí)驗(yàn)室發(fā)表的歷史論文pnpn型觸發(fā)晶體管,然后,在1958年通用電氣商業(yè)介紹了晶閘管。從那時(shí)起,有一個(gè)巨大的擴(kuò)張?jiān)诓煌较虻募夹g(shù)研究和開(kāi)發(fā)輻射如圖所示。

在功率半導(dǎo)體器件，研發(fā)繼續(xù)在不同的半導(dǎo)體材料，加工，制造和包裝技術(shù)，設(shè)備的建模與仿真，表征，和現(xiàn)代智能功率模塊（IPM）中發(fā)展。結(jié)果表明，在更高的額定功率和特性改進(jìn)下出現(xiàn)許多新設(shè)備的。從原始的二極管和晶閘管相控轉(zhuǎn)換器作為新設(shè)備的出現(xiàn)，隨著先進(jìn)的脈寬調(diào)制（PWM）技術(shù)，許多新的轉(zhuǎn)換器拓?fù)浣Y(jié)構(gòu)已經(jīng)被介紹，和分析與仿真理論。許多新的仿真軟件和計(jì)算機(jī)輔助設(shè)計(jì)技術(shù)有助于這些研究。出現(xiàn)了先進(jìn)的控制和信號(hào)評(píng)估技術(shù)，特別是用于交流電機(jī)驅(qū)動(dòng)。這些技術(shù)包括矢量或磁場(chǎng)定向控制，直接轉(zhuǎn)矩和磁通控制（DTC）控制，滑?；蜃兘Y(jié)構(gòu)控制，最優(yōu)控制，無(wú)傳感器控制，基于人工智能（AI）技術(shù)，如專家系統(tǒng)，模糊邏輯（FL），人工神經(jīng)網(wǎng)絡(luò)現(xiàn)代化智能控制，和遺傳算法。先進(jìn)的DSP和指定應(yīng)用集成電路（ASIC）芯片，隨著現(xiàn)代軟件工具，允許實(shí)現(xiàn)復(fù)雜的電力電子系統(tǒng)的控制和估計(jì)。功能強(qiáng)大的個(gè)人電腦的出現(xiàn)在進(jìn)化中也發(fā)揮了重要的作用。

在電力電子和電機(jī)驅(qū)動(dòng)器的歷史中有許多發(fā)明和里程碑，只有一些顯著的事件如圖所示.2。有趣的是要注意，“電力電子技術(shù)”名稱的引入系統(tǒng)是從20世紀(jì)70年代開(kāi)始。在進(jìn)化的早期階段，它被列為 “工業(yè)電子學(xué)”一個(gè)部分。2.為什么電力電子技術(shù)在今天是如此重要的？ 提到電力電子的應(yīng)用之前，可能表現(xiàn)出電力電子技術(shù)足夠的重要性。固態(tài)電力電子設(shè)備可以被看成一個(gè)高效率開(kāi)關(guān)模式功率放大器，那里的效率可能接近高達(dá)98％至99％。此外，該設(shè)備是靜態(tài)的，無(wú)音頻噪聲，并具有成本低，體積小，可靠性高，壽命長(zhǎng)相比之前用于類似功能的傳統(tǒng)設(shè)備。在現(xiàn)代自動(dòng)化工業(yè)環(huán)境中，基于電力電子的運(yùn)動(dòng)控制和計(jì)算機(jī)緊密合作增加了工業(yè)生產(chǎn)力，提高產(chǎn)品質(zhì)量。從廣義的角度來(lái)看，電力電子技術(shù)可以幫助一個(gè)國(guó)家，提供改善生活質(zhì)量的產(chǎn)業(yè)競(jìng)爭(zhēng)力。這也難怪，電力電子正在迅速蔓延從工業(yè)發(fā)達(dá)的國(guó)家到世界的發(fā)展中國(guó)家。

電力電子器件的另一個(gè)重要作用。21世紀(jì)它在節(jié)能和環(huán)境污染控制的趨勢(shì)下發(fā)揮著越來(lái)越重要的作用,如前所述。在全球范圍內(nèi), 為了改善我們的生活標(biāo)準(zhǔn)，電能消費(fèi)急劇增加。這是美國(guó)，那里的能源需求是貪婪的，尤其如此。世界上大部分的電力產(chǎn)于化石燃料和核電廠。燃燒化石燃料會(huì)對(duì)環(huán)境造成污染，其中包括新一代全球變暖的溫室氣體，而核電廠有安全和廢物處理的問(wèn)題。電力電子通過(guò)提高利用效率有助于節(jié)約能源本質(zhì)。根據(jù)電力研究院美國(guó)的（EPRI）的估計(jì)，在美國(guó)電網(wǎng)中大約60％至65％的能量被消耗在電動(dòng)機(jī)，以及它們的75％是泵，風(fēng)扇和壓縮機(jī)型電動(dòng)機(jī)。多數(shù)泵與風(fēng)機(jī)是用在工業(yè)環(huán)境中的流體流動(dòng)的控制。據(jù)悉，目前大約97％的中高功率驅(qū)動(dòng)器在流量控制操作以固定的速度通過(guò)機(jī)械方法，如節(jié)流控制，阻尼器，或流量控制閥這樣的應(yīng)用程序，從而導(dǎo)致了大量能量損失。在輕負(fù)載只有3%的這些驅(qū)動(dòng)器工作在節(jié)流閥完全打開(kāi)變頻調(diào)速，效率可以提高到達(dá)30%。同樣，在輕負(fù)載和降低速度由機(jī)器通量編程的一個(gè)可變頻率驅(qū)動(dòng)器，轉(zhuǎn)換器的效率可以得到改善。在基于電力電子負(fù)載比例速度控制空調(diào)可以比傳統(tǒng)的恒溫控制節(jié)省多達(dá)30％的能源。電力電子技術(shù)的額外的成本在一個(gè)時(shí)期可以通過(guò)取決于電的成本節(jié)約能源回收。例如，在日本電力成本較高。因?yàn)檫@個(gè)原因，大多數(shù)的日本家庭使用變速空調(diào)節(jié)能。近年來(lái)電力電子技術(shù)的一個(gè)流行的應(yīng)用是柴油電力推進(jìn)船舶變頻傳動(dòng)，相對(duì)于傳統(tǒng)的柴油機(jī)推進(jìn)可節(jié)省大量的燃料。據(jù)估計(jì)，在美國(guó)大約24%的能源消耗照明。基于電力電子的高頻緊湊型熒光燈（節(jié)能燈），除了提供更長(zhǎng)的使用壽命，還比傳統(tǒng)的白熾燈的效率高出四倍。節(jié)能燈的調(diào)光控制，可進(jìn)一步提高能源利用效率。該節(jié)能燈在不久的將來(lái)有望完全取代白熾燈。固態(tài)LED燈具有更高的效率和更長(zhǎng)的壽命將指日可待。高頻電磁爐和微波爐相比傳統(tǒng)的表面安裝烤箱也節(jié)省能源。根據(jù)電力科學(xué)研究院估計(jì)，電網(wǎng)能量的15％普遍能夠通過(guò)電力電子應(yīng)用程序容易地（但經(jīng)濟(jì)的）保存。節(jié)約能源不僅提供了直接的經(jīng)濟(jì)利益，而且有助于保護(hù)我們?nèi)找鏈p少的化石燃料和核燃料儲(chǔ)備。間接的有助于減輕對(duì)環(huán)境的污染，如全球變暖問(wèn)題。未來(lái)，隨著資源成本的進(jìn)一步增加，在電力電子技術(shù)的幫助下節(jié)約能源將被視為極為重要的。事實(shí)上，節(jié)能減排的這些方法可以讓國(guó)家強(qiáng)制性的的制定能源政策。

目前，對(duì)于利用我們龐大的風(fēng)能和太陽(yáng)能資源，這是可再生的，清潔環(huán)保，安全的發(fā)展趨勢(shì)。同時(shí)使用嚴(yán)重依賴電力電子的這些資源。歐洲風(fēng)能協(xié)會(huì)估計(jì)，估計(jì)可利用全球的風(fēng)能約10％可以提供所有全球電力需求[7][29]。同樣，功率半導(dǎo)體發(fā)展一直密切關(guān)注微電子的發(fā)展。在微電子研究人員不懈地努力，半導(dǎo)體加工，設(shè)備制造和包裝得到提高，這些努力促成了當(dāng)今許多先進(jìn)的功率器件的成功演變。

晶閘管（可控硅整流器或）和三端雙向可控硅實(shí)質(zhì)上是現(xiàn)代功率器件的先行者，他們主導(dǎo)第一代的固態(tài)電力電子[20]（1958年至1975年）。這些設(shè)備主要是操作上的實(shí)用系統(tǒng)，并有助于電能質(zhì)量和滯后位移功率因數(shù)（DPF）的問(wèn)題的改進(jìn)。今天，晶閘管是必不可少的處理高功率低頻率的應(yīng)用，如高壓直流轉(zhuǎn)換器，相控SVC時(shí)，周波變換器和負(fù)載改判逆變器（LCI）驅(qū)動(dòng)器。在不久的將來(lái)，大功率晶閘管處理的主導(dǎo)地位至少不會(huì)受到挑戰(zhàn)。但是，由于固有的缺點(diǎn)的，相位控制裝置最終將通過(guò)在PWM或階梯波模式操作自主控制裝置代替。大功率門(mén)極可關(guān)斷晶閘管（GTOs）的出現(xiàn)，主要由日本企業(yè)[22]，這種強(qiáng)迫換流晶閘管變流器已經(jīng)被趕盡殺絕了。該設(shè)備（最大6千伏，6千安）仍然是非常流行的多兆瓦電壓反饋（與前瞻性閉塞裝置）和電流反饋（帶反向阻斷器）轉(zhuǎn)換器應(yīng)用。該裝置的緩慢的切換需要大的吸收電路會(huì)引起大的開(kāi)關(guān)損耗，因此，在低開(kāi)關(guān)頻率（幾百赫茲）限制了它的應(yīng)用。能源回收或再生吸收回路中的門(mén)極可關(guān)斷晶閘管脈寬調(diào)制轉(zhuǎn)換器通常用于以提高轉(zhuǎn)換效率。功率場(chǎng)效應(yīng)管與大多數(shù)其他器件都是多數(shù)載流子器件，并且因此，在高電壓等級(jí)其導(dǎo)通壓降高，而且由于快速開(kāi)關(guān)開(kāi)關(guān)損耗低。在“溝槽柵”器件現(xiàn)已與低壓降導(dǎo)通。近日，高電壓（高達(dá)800 V）的CoolMOS器件已經(jīng)介紹了基于超級(jí)結(jié)的設(shè)計(jì)英飛凌科技[23]，導(dǎo)通損耗一直與正常設(shè)備比較減少很多。CoolMOS已經(jīng)提出了用SiC肖特基二極管操作以繞過(guò)主設(shè)備的慢速體二極管。預(yù)計(jì)功率MOSFET將在未來(lái)仍然受到質(zhì)疑低電壓高頻率的應(yīng)用。不幸的是，大型雙極結(jié)型晶體管（BJT），曾經(jīng)那么流行的設(shè)備在20世紀(jì)70年代，現(xiàn)在已經(jīng)過(guò)時(shí)。對(duì)于電源的低端，雙極結(jié)型晶體管已被替換功率場(chǎng)效應(yīng)管，而在高端，他們已經(jīng)絕緣柵雙極晶體管（IGBT）被取代了。IGBT的發(fā)明已經(jīng)是功率半導(dǎo)體器件[24]歷史上一個(gè)重要里程碑。現(xiàn)代的IGBT可與溝槽柵穿通技術(shù)的低壓降導(dǎo)通 [25]。這種自我控制的混合裝置結(jié)合了功率場(chǎng)效應(yīng)管和雙極型晶體管。它的額定功率的優(yōu)勢(shì)不斷增加（目前為6.5千伏，700 A和10千伏設(shè)備正在測(cè)試）以及電氣特性的改善。IGBT IPMs可與內(nèi)置柵極驅(qū)動(dòng)器控制和保護(hù)高達(dá)幾百匹馬力交流電機(jī)驅(qū)動(dòng)器。目前看來(lái)，在未來(lái)的絕緣柵器件（功率MOSFET和IGBT）將繼續(xù)在電力電子應(yīng)用領(lǐng)域占據(jù)主導(dǎo)地位。大功率（6.5千伏，4千安）集成門(mén)極換流晶閘管（IGCTs）（orGCT）在最近幾年，被引入正向和反向阻斷功能?，F(xiàn)在大功率IGBT和IGCT是多兆瓦轉(zhuǎn)換器嚴(yán)重的競(jìng)爭(zhēng)對(duì)手。在高額定功率，IGBT和IGCT具有相當(dāng)?shù)拈_(kāi)關(guān)頻率，允許無(wú)緩沖器操作。但是，在更高的額定電壓，IGBT趨于抵消絕緣柵極驅(qū)動(dòng)和自我保護(hù)的優(yōu)勢(shì)更大導(dǎo)通壓降。GTOs目前在低壓被IGBT的取代，在高壓被IGCT取代。靜電感應(yīng)晶體管是一種結(jié)型場(chǎng)效應(yīng)晶體管（JFET），通常在設(shè)備上有大型導(dǎo)通壓降，本質(zhì)上是一種真空三極管。它可以被應(yīng)用在大功率的高頻轉(zhuǎn)換器上。還有一些還沒(méi)有投入生產(chǎn)其他的設(shè)備，諸如場(chǎng)效應(yīng)管控制的晶閘管，靜電感應(yīng)晶閘管，注入增強(qiáng)柵晶體管，場(chǎng)效應(yīng)可關(guān)斷晶閘管等。此外，也有一些在改進(jìn)[24]的設(shè)備，[26]。

Although silicon has been the basic raw material for the current devices, large bandgap materials, such as SiC(3.0 eV)and diamond(in synthetic thin-film form)(5.5 eV), show tremendous promise for the future [27], [28].

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(mén)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(lái)實(shí)現(xiàn)十字路口交通燈智能化的管理，用以控制過(guò)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(guò)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(lái)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(kāi)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(wèn)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(wèn)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(lái)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(guò)估計(jì)每輛車的好處(或收益)來(lái)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(guò)有聚類算法的基礎(chǔ)設(shè)施，最后經(jīng)過(guò)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(guò)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(wèn)題得出結(jié)論。第4部分說(shuō)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(guò)這種方式，增加軟件的獨(dú)立性和為其他的軟件開(kāi)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(kāi)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?！氨倔w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(yǔ)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(guò)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(lái)，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(yǔ)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(guò)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(lái)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(yǔ)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(shuō)明在這項(xiàng)工作中的應(yīng)用技術(shù)包括語(yǔ)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(yǔ)義網(wǎng)絡(luò)技術(shù)

語(yǔ)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(yǔ)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(jiàn)。評(píng)價(jià)過(guò)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(guò)程中，準(zhǔn)備以調(diào)查問(wèn)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(lái)自德黑蘭的交通組織工程師。由于德?tīng)柗茖＜业囊庖?jiàn)，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(guò)程中進(jìn)行了兩項(xiàng)活動(dòng)，包括檢查的要求和能力的問(wèn)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(wèn)題?？?jī)效評(píng)估機(jī)制，可以支持這種說(shuō)法。在部分實(shí)驗(yàn)結(jié)果我們驗(yàn)證了這一過(guò)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(jiàn)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(kāi)挖已經(jīng)建設(shè)好的建筑設(shè)施來(lái)改造排水系統(tǒng)的現(xiàn)象。城市污水給人們帶來(lái)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(kāi)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(shuō)，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(lái)說(shuō)，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(tīng)語(yǔ)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(lái)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(lái)越多的人所用，但是隨之而來(lái)的問(wèn)題也顯而易見(jiàn)，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(guò)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(kāi)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(kāi)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(kāi)機(jī)自檢功能。目前市場(chǎng)上還出現(xiàn)了具有語(yǔ)音報(bào)警功能的產(chǎn)品。這些產(chǎn)品存在的主要問(wèn)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(wú)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(guò)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(guò)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(lái)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(guò)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(lái)工作的。超聲波發(fā)生器內(nèi)部結(jié)構(gòu)，它有兩個(gè)壓電晶片和一個(gè)共振板。當(dāng)它的兩極外加脈沖信號(hào)，其頻率等于壓電晶片的固有振蕩頻率時(shí)，壓電晶片將會(huì)發(fā)生共振，并帶動(dòng)共振板振動(dòng)，便產(chǎn)生超聲波。反之，如果兩極板間未加電壓，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(kāi)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(guò)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(shuō)，從脈沖起始點(diǎn)到剛好超過(guò)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(guò)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(guò)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(kāi)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(lái)，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

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

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

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

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(lái)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(guò)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?，作為中斷?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(guò)與門(mén)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(lái)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(kāi)外部中斷1

pop acc

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

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(guò)零時(shí)間。

計(jì)算時(shí)間值 存儲(chǔ)結(jié)果

開(kāi)外部中斷0

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

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(guò)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(guò)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(guò)在低氣壓插入振幅。

第六步：通過(guò)公式計(jì)算距離y。

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

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。

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

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(jiàn)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。

中原工學(xué)院畢業(yè)設(shè)計(jì)（論文）譯文

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

中原工學(xué)院畢業(yè)設(shè)計(jì)（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(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,