【正文】 The st ri ke is due t o begi n on Tuesday. No one knows how long i t wil l last . The busmen have stated t hat t he st ri ke wil l cont inue unt il gener al agr em ent is r eached about pay and worki ng condi tions. Most pe ople beli eve that he str ike wi l last for at least a week. Many owners of pri vat e cars are goi ng to of fer 39。Do you al ways catch such an ear ly tr ai n 39。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。 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。Excuse m e inter rupti ng you. I hate t o i nt er upt a m an when he39。 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 共 44 頁 第一章 緒論 倒立擺系統(tǒng)的簡介 倒立擺系統(tǒng)的研究背景 及意義 倒立擺系統(tǒng)的最初分析研究開始于二十世紀五十年代，是一個比較復(fù)雜的不穩(wěn)定、多變量、帶有非線性和強耦合特性的高階機械系統(tǒng)，它的穩(wěn)定控制是控制理論應(yīng)用的一個典型范例 [1]。非線性是造成混亂、無序或混沌的核心因素，造成混亂、無序或混沌并不意味著需要復(fù)雜的原因，簡單的非線性就會產(chǎn)生非常的混亂、無序或混沌。 I tol d you yest er day and the day bef ore yesterday,39。 tim e. Even so, peopl e are goi ng to f ind i t dif fi cul t to get to wor k. But so f ar, t he publ ic has expr esed it s grati tude t o the students i n let ters t o t he Pr es. Only one or t wo peopl e have obj ect ed that the student s wi l dri ve too f ast ! Lesson85 Never too ol d to learn 活到老學到老 I have just recei ved a let er fr om m y old school i nf orm ing me that my f or mer head master , Page, wi l l be r eti ri ng next week. Pupil s of the school , ol d and new, wi l l be sendi ng him a pr esent t o mar k the occasi on. Al l those 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。 answer ed t he m an. 39。t not ice anything unusual . I suggest, 39。t t hi nk the wi ndows need cl eaning at t hi s ti me of t he ni ght.39。 I sai d. 39。之所以采用欠冗余的設(shè)計是要在不失系統(tǒng)可靠性的前提下節(jié)約經(jīng)濟成本或者節(jié)約有效的空間。 倒立擺的以上特性增加了倒立擺的控制難度，也正是由于倒立擺的這些特性，使其更具有研究價值和意義 [3]。 which have at t imes been si ghted are si mply st range fi sh. Occasi onal y, unusual creatur es ar e washed t o t he shore, but they are r arely caught out at sea. Some ti me ago, however, a pecul iar fi sh was caught near Madagascar . A smal l f i shing boat was car r ied mi les out to sea by the power ful fi sh as it pulled on the li ne. Reali zing t hat thi s was no or di nar y f ish, t he fi sher man made ever y ef ort not to damage i t i n any way. When it was event ualy brought t o shor e, i t was found t o be over t hi r teen feet long. I t had a head l ike a hor se, big bl 。在此基礎(chǔ)上，人們又進行拓展，產(chǎn)生了多種形式的倒立擺。 (4)耦合特性倒立擺擺桿和小車之間，以及多級倒立擺系統(tǒng)的上下擺桿之間都是強耦合的。ve f or got t en m y key. He cal l ed. 39。I enjoy cl eani ng windows at night. 39。t hat you are not t el li ng the t rut h. I suggest that you di d not cat ch the o39。cl ock. My employer wil l conf ir m t hat I was t her e on ti me. Would a lat er t rain get you t o work on ti me? asked the i nspector . 39。At the t im e the m ur der was m i t ed, I was tr avel li ng on the 8. 0 o39。 I know, 39。 無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典型的非線性復(fù)雜系統(tǒng)。通過對它的研究不僅可以解決控制中的理論問題，還將控制理論涉及的相關(guān)主要學科：機械、力學、數(shù)學、電學和計算機等綜合應(yīng)用。d pr ef er t o st ay her e, 39。 I don39。And you di dn39。Of cour se I do, 39。 t o peopl e on t hei r way to wor k. This wi l r el ieve pressur e on t he tr ai ns to some extent. Meanwhi le, a num ber of universit y student s have vol unt eer ed to dr ive buses whi le the str ike l asts. Al l the young men are ex