【正文】 ll be traveling fast, so despite the distance, it will not be like 61 diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jump When he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will 。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場(chǎng)還沒有開始就宣告了終結(jié)的邂逅計(jì)劃 …… 那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。 Have declared the end of the encounter that haven39。 Those were broken into various shapes of stationery。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說，是自以為是的精神寄托罷了。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時(shí)候是最后又打起了退堂鼓。s time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a selfrighteous spiritual. 一個(gè)人的時(shí)候，自己的想法總是特別地清晰。 Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time. 原來， 這個(gè)世界上，對(duì)某個(gè)事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時(shí)間。t want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can39。t really grow up, it seems is not so important。 The end of our life, and can meet many things really do? 而窮盡我們的一生，又能遇到多少事情是真正地非做不可？ During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional?？傆X得自己自己似乎應(yīng)該去做點(diǎn)什么，或者寫點(diǎn)什么。 May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it. 一字開頭的年齡已經(jīng)到了尾聲。s actions. CSKA said they were surprised and disappointed by Toure39。s 21 win. Michel Platini, president of European football39。s Premier League match at Chelsea on Sunday. I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport. For me it39。s antiracism taskforce, is in London for the Football Association39。t charge you more than 35% of your pensation if you win the case. If you are thinking about signing up for a damagesbased agreement, you should make sure you39。t agree with the disciplinary action your employer has taken against you ? your employer dismisses you and you think that you have been dismissed unfairly. For more information about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。課程設(shè)計(jì)不 僅是一次對(duì)所學(xué)知識(shí)的應(yīng)用，更是一個(gè)培養(yǎng)團(tuán)結(jié)合作精神的平臺(tái)，它讓我收獲了知識(shí)，讓我領(lǐng)會(huì)了協(xié)作精神，更讓我燃起了對(duì)學(xué)術(shù)的熱情。 （ 4） 通過此次課程設(shè)計(jì)，我深刻體會(huì)到團(tuán)隊(duì)的重要性。實(shí)際 生產(chǎn)生活中很多設(shè)備并不能直接更改參數(shù)，這影響了理論研究，但通過對(duì)實(shí)際模型的仿真，很好的解決了此類問題，在工程上有很大意義。這些實(shí)驗(yàn)中直觀得到的結(jié)論與課本中的理論相符，讓我加深了對(duì)課本的理解。通過探究速度、電流雙閉環(huán)調(diào)速系統(tǒng)的運(yùn)行，并研究斜坡函數(shù)發(fā)生器的參數(shù)設(shè)定及波形調(diào)整，改變斜率觀察系統(tǒng)特性等操作，更深入的理解了 閉環(huán)控制系統(tǒng)中比例環(huán)節(jié)和積分環(huán)節(jié)的作用。 （ 2） 將在自動(dòng)控制系統(tǒng)中所學(xué)到的理論知識(shí)與實(shí)際相結(jié)合。 56 6 使用儀器設(shè)備清單 (1)SIMENS 6RA70 系列直流控制系統(tǒng) (2)主電機(jī) (3)磁粉制動(dòng)器 (4)計(jì)算機(jī)（ DriveMotor 軟件、 matlab 軟件） 57 7 收獲和體會(huì) 經(jīng)過此次課程設(shè)計(jì)，我 收獲頗豐，主要可歸結(jié)為以下幾點(diǎn)： （ 1） 了解了 SIEMENS 直流調(diào)速系統(tǒng) 6RA70 的功能，掌握了外部接線方法，并研讀了一部分功能圖。 通過更改比例系數(shù)與積分時(shí)間常數(shù)可得到較為理想的運(yùn)行軌跡，但實(shí)際中有些情況（如大型設(shè)備等）不易直接更改參數(shù)。 在實(shí)驗(yàn)中，速度、電流雙閉環(huán)調(diào)速系統(tǒng)的參數(shù)可由 6RA70 系統(tǒng)自行優(yōu)化，通過斜坡函數(shù)發(fā)生器的參數(shù)設(shè)定及波形調(diào)整，改變斜率觀察系統(tǒng)特性，可分析出比例環(huán)節(jié)與積分環(huán)節(jié)對(duì)控制系統(tǒng)的作用及影響： PI 控制中的比例環(huán)節(jié)主要作用是產(chǎn)生和偏差成比例變化的控制作用來減少偏差。它最大的優(yōu)點(diǎn)是不需了解被控對(duì)象精確的數(shù)學(xué)模型，只需在線根據(jù)系統(tǒng)誤差及誤差的變化率等簡單參數(shù)，經(jīng)過經(jīng)驗(yàn)進(jìn)行調(diào)節(jié)器參數(shù)在線整定，即可取得滿意的結(jié)果。 目前使用的雙閉環(huán)直流調(diào)速系統(tǒng) ,是按典型系統(tǒng)采用 PI 控制器串聯(lián)校正來設(shè)計(jì)轉(zhuǎn)速環(huán)和電流環(huán)的。 55 5 結(jié)論 當(dāng)今，自動(dòng)化控制系統(tǒng)己經(jīng)在各行各業(yè)得到了廣泛的應(yīng)用和發(fā)展，直流調(diào)速控制因其具有良好的起動(dòng)，制動(dòng)性能，適合在廣泛的范圍內(nèi)平滑調(diào)速，在現(xiàn)代化生產(chǎn)中起著重要作用，在需要高性能可控電力拖動(dòng)的領(lǐng)域中得到了廣泛的應(yīng)用。應(yīng)該多選取幾組數(shù)據(jù)，并多 建立幾個(gè)模型，經(jīng)分析得到最佳模型。 （ 1） 仿真過程中反饋為單位反饋，而實(shí)際電機(jī)由于受設(shè)備等影響，反饋不是標(biāo)準(zhǔn)單位反饋。 由于 Matlab 和 Simulink是集成在一起的 ,因此用戶可以在這兩種環(huán)境下對(duì)自已的模型進(jìn)行仿真、分析和修改。除此之外 ,用戶還可以在改變參數(shù)后能迅速觀看系統(tǒng)中發(fā)生的變化情況。 菜單方式對(duì)于交互工作非常方便 ,而命令行方式對(duì)于運(yùn)行一類仿真非常有用。用戶可以從最高級(jí)開始觀看模型 ,然后用鼠標(biāo)雙擊其中的子系統(tǒng)模塊 ,來查看其下一級(jí)的內(nèi)容 ,以此類推 ,從而可以看到整個(gè)模型的細(xì)節(jié) ,幫助用戶理解模型的結(jié)構(gòu)和各模塊之間的相互關(guān)系。用戶也可以定制和創(chuàng)建用戶自已的模塊。它與傳統(tǒng)的仿真軟件包用微分和差分方程建模相比 ,具有更直觀、方便、靈活的優(yōu)點(diǎn)。因此可以不難理解它自推出以后 ,就一直受到歐美和日本等國家或地區(qū)的控制界學(xué)者的青睞。既可對(duì)連續(xù)系 統(tǒng)也可對(duì)離散系統(tǒng)進(jìn)行仿真 ,還適合于采樣保持系統(tǒng)。既可以純圖形方式輸入 ,也可以純文本方式來輸入。 Simulink 是一個(gè)用來對(duì)動(dòng)態(tài)系統(tǒng)進(jìn)行建模、仿真和分析的軟件包 ,不僅界面友好且支持更靈活的模型描述手段。 根據(jù) Z 變換的定義，將象函數(shù))(zF展開成1?z的無窮冪級(jí)數(shù)，即 ??? ?? 0 )()( n nznTfzF =??????????? ??? nznTfzTfzTff )()2()()0( 21 設(shè)形如函數(shù))(zF是 z 的有理函數(shù)，可表示為兩個(gè) z 的多項(xiàng)式之比，即 nnnmmm azaza bzbzbzF ?????? ??????? ??110110)( )( nm? 對(duì)上式用長除法，用分母多項(xiàng)式去除分子多項(xiàng)式，所得商按1?z的升冪排列 nnzczczcczF ??? ???????? 22110)( =??? ?0n nnzc 如果所得到的無窮冪級(jí)數(shù)是收斂的，則按 Z 變換定義可知，上式中的系數(shù) ),1,0( ?????n就是采樣脈沖序列)(* tf的脈沖強(qiáng)度)(nTf。 離散系統(tǒng)連續(xù)化 46 在離散系統(tǒng)中應(yīng)用 Z 變換，是為了把 s 的超越方程或者描述 離散系統(tǒng)的差分方程轉(zhuǎn)換為 z 的代數(shù)方程，然后寫出離散系統(tǒng)的脈沖傳遞函數(shù)，再用 Z 反變換法求出離散系統(tǒng)的時(shí)間響應(yīng)。 由于篇幅限制只列舉 400 組數(shù)據(jù)中的前 50 組，如下表所示： Pos, Actualspeed, Iaactvalue, RFGoutput 0, 1, 0, 2 1, 1, 0, 1 2, 2, 0, 4 3, 1, 0, 1 4, 1, 0, 1 5, 0, 0, 0 6, 2, 0, 2 7, 0, 0, 1 8, 2, 0, 4 9, 1, 0, 1 10, 0, 0, 1 11, 6, 0, 4 12, 1, 0, 2 13, 0, 0, 1 14, 8, 0, 8 15, 2, 0, 4 16, 0, 0, 1 17, 2, 0, 4 18, 101, 0, 124 19, 153, 0, 135 20, 99, 0, 87 21, 41, 0, 79 22, 54, 0, 31 44 表 41 系統(tǒng)的 輸入輸出數(shù)據(jù) t1=arx([y,u],[3 1 0]) 23, 28, 0, 27 24, 24, 0, 51 25, 49, 0, 22 26, 27, 0, 29 27, 21, 0, 48 28, 48, 0, 17 29, 31, 0, 29 30, 27, 0, 51 31, 54, 0, 24 32, 32, 0, 32 3