【正文】 e who have contr ibuted t owards t he gi ft wi l sign their names in a large album which wi l be sent t o t he headmast er39。f r e r i des39。 but I l ove to hear you say i t39。 I know, 39。 I tol d you yest er day and the day bef ore yesterday,39。s Radi cal Progr essive Part y. Af t er t he elect ions, Crawl ey went t o the f orm er Pr im e Mi nister39。monst ers39。 無(wú)論哪種類型的倒立擺系統(tǒng)都具有如下特性 [2]： (1)非線性倒立擺是一個(gè)典型的非線性復(fù)雜系統(tǒng)。非線性是造成混亂、無(wú)序或混沌的核心因素，造成混亂、無(wú)序或混沌并不意味著需要復(fù)雜的原因，簡(jiǎn)單的非線性就會(huì)產(chǎn)生非常的混亂、無(wú)序或混沌。倒立擺系統(tǒng)是一個(gè)典型的自不穩(wěn)定系統(tǒng)，其中擺作為一個(gè)典型的振動(dòng)和運(yùn)動(dòng)問(wèn)題，可以抽象為許多問(wèn)題來(lái)研究。近些年來(lái)，國(guó)內(nèi)外不少專家、學(xué)者一直將它視為典型的研究對(duì)象，提出了很多控制方案，對(duì)倒立擺系統(tǒng)的穩(wěn)定性和鎮(zhèn)定問(wèn)題進(jìn)行了大量研究，都在試圖尋找不同的控制方法實(shí)現(xiàn)對(duì)倒立擺的控制，以便檢查或說(shuō)明該方法的嚴(yán)重非線性和絕對(duì)不穩(wěn)定系統(tǒng)的控制能力，其控制方法在軍工、航天、機(jī)械人領(lǐng)域和一般工業(yè)過(guò)程中都有著廣泛的用途，如精密儀器的加工、機(jī)器人行走過(guò)程中的平衡控制、火箭發(fā)射中的垂直度控制、導(dǎo)彈攔截控制、航空對(duì)接控制、衛(wèi)星飛行中的 姿態(tài)控制等方面均涉及到倒置問(wèn)題。通過(guò)對(duì)它的研究不僅可以解決控制中的理論問(wèn)題，還將控制理論涉及的相關(guān)主要學(xué)科：機(jī)械、力學(xué)、數(shù)學(xué)、電學(xué)和計(jì)算機(jī)等綜合應(yīng)用。 For t unat el y, t he shout i ng woke up m y wi f e who opened t he wi ndow j ust as t he pol i cem an had st ar t ed t o cl i m b t owar ds m e. Lesson93 A nobl e gi f t 崇高的禮物 One of t he m ost f am ous m onum ent s i n t he wor l d, t he St at ue of Li ber t y, was pr esent ed t o t he Uni t ed St at es of Am er i ca i n t he ni eent h cent ur y by t he peopl e of Fr ance . The gr eat st at ue, whi ch was desi gned by t he scul pt or August Bar t hol di , t ook t en year s t o pl et e. The 第 1 頁(yè) 共 44 頁(yè) 第一章 緒論 倒立擺系統(tǒng)的簡(jiǎn)介 倒立擺系統(tǒng)的研究背景 及意義 倒立擺系統(tǒng)的最初分析研究開(kāi)始于二十世紀(jì)五十年代，是一個(gè)比較復(fù)雜的不穩(wěn)定、多變量、帶有非線性和強(qiáng)耦合特性的高階機(jī)械系統(tǒng)，它的穩(wěn)定控制是控制理論應(yīng)用的一個(gè)典型范例 [1]。My key, 39。You see, I 39。d pr ef er t o st ay her e, 39。Excuse m e inter rupti ng you. I hate t o i nt er upt a m an when he39。 So do I, 39。 I l ooked down and near ly fel of f the ladder when I saw a pol iceman. I imm edi at ely r egr et ed answeri ng in the way I did, but I sai d, 39。 I don39。 Leson88 Trapped in a m ine 困在礦井里 Si x men have been t rapped in a mine f or seventeen hour s. I f they are not br ought to t he sur f ace soon they may l ose t hei r li ves. However , rescue operat ions are pr ovi ng dif fi cul t. I f explosives are used, vi br ati ons wi l l cause the r oof of the m ine t o colapse. Rescue wor ker s are t her efor e dri l ing a hole on the nort h side of the m ine. They i ntend t o bri ng the men up in a speci al capsul e. I f there had not been a har d layer of rock beneath the soi l, t hey woul d have pl eted the j ob in a few hour s. As it is, they have been dr il li ng for sixteen hours and they sti l have a long way to go. Meanwhile, a m icrophone, whi ch was lowered i nto t he mi ne t wo hours ago, has enabled the m en to keep in touch wi th t he cl osest relat ives. Though they are r unni ng out of f ood and dri nk, the m en ar e cheer ful and conf ident that they wil l get out soon. They have been tol d that rescue operat ions ar e pr ogr esing smoothl y. I f they knew how di f icult i t was to dr il l through t he har d r ock, they would lose hear t. Lesson89 A sli p of the t ongue 口誤 People wi l do anything t o see a fr ee showeven i f it is a bad one. When the news got round t hat a vari ety show woul d be present ed at our local ci nem a by the P. and U. Bir d Seed Company, we al l rushed t o see it . We had t o queue f or hour s to get in and t her e must have been several hundr ed peopl e present just bef ore t he show began. Unfor tunat ely, the show was one of the dull est we have ever seen. Those who fail ed to get i n need not have f elt disappoi nted as many of the ar tist es who should have appeared di d not e. The only f unny things we heard that evening came f rom the adver ti ser at the beginning of t he. He was obviously ve r y ner vous and f or som e minut es stood awkwar dl y befor e the m icrophone. As soon as he opened his m out h, everyone burst out l aughing. We al l know what he poor m an should have sai d, but what he act ual ly said was: This i s Seed Bir d Company. Good l adi es, eveni ng and gent lemen!39。cl ock tr ai n, but t hat you caught the which would st il l get you to work on tim e. You see, on the mor ning of the m urder, t he 8. 0 o39。 said the i nspect or, 39。And you di dn39。At what t ime di d you ar ive at the stat ion? eight. I bought a paper and wai ted f or t he tr ain.39。I suppose i t would, but I never catch a later tr ain.39。 I m ust be at work at o39。Of cour se I do, 39。Do you al ways catch such an ear ly tr ai n 39。clock tr ain t o London, 39。s hom e. We shal al l r emember Page f or hi s patience and under st andi ng and f or the ki ndl y encouragement he gave us when we went so unwil li ngl y to school. A gr eat m any f orm er pupil s wi l be atending a farewel l di nner i n his next Thur sday. It i s a cur ious coincidence t hat t he day bef ore hi s reti rement , Page wi l have been t eaching f or a total of for ty years. Af ter he has r eti red, he wil l devote hi msel f to gar deni ng. For him, t his wi l be an enti rely new hobby. But this does not m at ter , for, as he has oft en remarked, one i s never t oo ol d t o learn. Leson86 Out of contr ol 失控 As the m an tr ied t o swi ng t he speed boat r ound, the st er ingwheel came away i n hi s hands. He waved desper ately t o his panion, who had been wat er ski ing f or t he last fi ft en m inutes. Bot h m en had hardl y had ti me t o reali ze what was happeni ng when the y wer e thr own violent1y into the sea. The speedboat had st ruck a buoy, but it continued t o move very quickl y acr oss t he water. Bot h men had j ust begun t o swim t owar ds the s hore. they noti ced wi th dismay that the speed boat was moving i n a ci rcle. It now came st raight towar ds them at tr emendous speed. In les than a mi nut e, i t roared past them only a few feet away. Af ter it had pased, t hey swam on as qui ckly as t hey could because t hey knew t hat t he boat would soon r eturn. They had just had enough ti me t o swi m out of danger when t he boat agai n pleted a ci rcle. O