雙柱式升降機設(shè)計

雙柱式升降機設(shè)計,雙柱式,升降機,設(shè)計 畢業(yè)論文答辯畢業(yè)論文答辯PPTPPT北華航天工業(yè)學院2017級機電工程學院 答辯人指導老師胡曉斌賀俊杰1升降機的簡介THEBACKGROUNDOFTHESUBJECTANDCONTENT設(shè)計原理PRESENTSITUATIONANDDEVELOPMENTOFSUBJECT升降機總體方案設(shè)計THERESEARCHMENTALITYANDTHEPROCESS各個機構(gòu)設(shè)計THERESULTSOFEXPRIMENTALDATA參考文獻及致謝SOLUTIONSANDSUMMARY2345目錄/Contents升降機的發(fā)展1845年，第一次工業(yè)革命出現(xiàn)了第一部工業(yè)水壓式的升降機，1857年，首部客運升降機在美國紐約的一家商場安裝，開創(chuàng)了升降機載人的先河。1880年，德國人西門子發(fā)明了電動的升降機。我國升降機發(fā)展較晚，從20世紀90年代開始，中國的升降機才開始慢慢普及。升降機的分類升降機的類型繁多,根據(jù)其結(jié)構(gòu)類型一般可分為雙柱式升降機、四柱式升降機、剪式升降機等。根據(jù)升降機的驅(qū)動類型分類，升降機大體上可分為機械式和液壓式兩類。本次設(shè)計的升降機本次畢業(yè)設(shè)計研究的方向是雙柱式機械式升降機。機械式升降機雖然維護成本雖然有些高，但是同步性好，不存在漏油污染問題，自鎖保護簡單易行，升降機性能的好壞受多種因素的影響。l升降機簡介l設(shè)計原理運用帶傳動將電動機的動力傳遞給大帶輪，大帶輪通過鍵連接傳遞給滑動螺旋副，螺旋副中的絲杠螺桿可以將傳來的旋轉(zhuǎn)運動轉(zhuǎn)換為螺母的直線運動，帶動懸臂梁以及梁上物體實現(xiàn)升降。01電機配置 雙電機方案02升降機構(gòu) 滑動螺旋傳動03導軌機構(gòu) 滾動直線導軌04鎖緊機構(gòu)采用適用于固定Z軸上使用的導軌鉗制器設(shè)計方案總結(jié)原動機為分別安裝在左右立柱上的兩電機，通過兩電機的通斷電實現(xiàn)左右螺桿的同步運動，螺桿把轉(zhuǎn)動轉(zhuǎn)變?yōu)橹本€運動，從而是螺母同步上下運動，實現(xiàn)物體升降。l總體方案帶傳動設(shè)計升降機構(gòu)設(shè)計支撐機構(gòu)設(shè)計導軌機構(gòu)設(shè)計鎖緊機構(gòu)設(shè)計l各個機構(gòu)設(shè)計l帶傳動設(shè)計123帶的設(shè)計V帶的主要失效形式主要有：1）帶在帶輪上打滑，不能傳遞動力；2）帶由于疲勞產(chǎn)生脫層、撕裂和拉斷；3）帶的工作面磨損。帶傳動的計算設(shè)計功率：2.32kw帶型：A型4根V帶傳動比：4帶輪基準直徑：大帶輪335mm小帶輪85mm帶速：4.27m/s帶輪結(jié)構(gòu)的設(shè)計帶輪的主要組成部分有輪緣、輪輻和輪轂。通過查閱機械設(shè)計手冊，最終確定小帶輪為實心輪，大帶輪為孔板輪，材料均為HT200。輪槽的工作表面應(yīng)盡可能光滑。擇較為普遍的普通V帶傳動，結(jié)構(gòu)為繩芯結(jié)構(gòu)。結(jié)構(gòu)簡單、成本低、傳動穩(wěn)定、不需要潤滑l舉升機構(gòu)設(shè)計螺旋傳動分為滑動螺旋傳動、滾動螺旋傳動和靜壓螺旋傳動三類。選擇滑動螺旋傳動：結(jié)構(gòu)簡單、易于自鎖、運轉(zhuǎn)平穩(wěn)。舉升機構(gòu)螺紋分為梯形螺紋、鋸齒形螺紋、矩形螺紋。選擇梯形螺紋：牙根強度高，工藝性好；對中性好，不易松動；可以調(diào)整和消除間隙。螺母分為整體螺母、組合螺母和剖分式螺母采用整體螺母：結(jié)構(gòu)簡單設(shè)計計算螺距：10mm螺母工作高度：98mm旋合圈數(shù)：10螺紋工作高度：5mm當量摩擦角：6螺紋升角：5自鎖l支撐機構(gòu)設(shè)計當成載物體進入到升降機的范圍里時，升降機的整個工作范圍的寬度就可以隨著懸臂的角度和長度的改變而改變。本次設(shè)計的支撐機構(gòu)為對稱式懸臂，有利于保持承載物體的穩(wěn)定性，使立柱中各機構(gòu)的受力更均勻。懸臂由兩段部分組成，可以根據(jù)實際情況來改變懸臂的長度，其伸縮范圍為250mm.校核彎曲切應(yīng)力校核彎曲正應(yīng)力懸臂結(jié)構(gòu)懸臂結(jié)構(gòu)圖計算l導軌結(jié)構(gòu)設(shè)計直線導軌通常分為滑動直線導軌、滾動直線導軌和靜壓直線導軌三種。本次設(shè)計采用滾動直線導軌：運行速度不會太低，剛度、可靠性較高。選擇四方向等載荷型滾動直線導軌。承載能力大，剛性好；摩擦因數(shù)小，節(jié)省動力；面接觸，磨損小，壽命長；兩側(cè)安裝有互為垂直的兩列承載滾珠，剛性好，承受沖擊較大。l鎖緊機構(gòu)設(shè)計在一個固定的Z軸上運用導軌鉗制器，防止懸臂在工作停止時滑落。其制動的動力為氣壓，并且為常閉型。當電機停止工作時沒有氣壓被供給，導軌鉗制器便依靠特殊彈簧的作用夾緊軸，使托臂固定在所要求的位置。當電機工作時會供給給鉗制器氣壓，彈簧便會松開不會對升降產(chǎn)生影響。鎖緊光軸的直徑：28mm導軌鉗制器l參考文獻1 郭武，黃澤星，吳上生.汽車舉升機的發(fā)展趨勢分析J.應(yīng)用研究,2011:75-79.2 上官紅喜.一種雙柱汽車舉升機的設(shè)計J.液壓與氣動,2013（13期）:106-109.3 機械設(shè)計手冊編委會.機械設(shè)計手冊單行本帶傳動和鏈傳動M.北京:機械工業(yè)出版社,2007.2.4 機械設(shè)計手冊編委會.機械設(shè)計手冊單行本帶彈簧 摩擦輪及螺旋傳動軸 M.北京:機械工業(yè)出版社,2007.2.5 成大先.機械設(shè)計手冊單行本軸承M.北京:化學工業(yè)出版社,2004.1.6 良貴，紀名剛.機械設(shè)計M.北京:高等教育出版社,2006.5.7 劉鴻文.材料力學IM.北京:高等教育出版社,2011.1.8 孫桓，陳作模，葛文杰.機械原理M.北京:高等教育出版社,2006.5.9 高為國，鐘利萍.機械工程材料M.長沙:中南大學出版社,2012.9.10 Neil Sclater,Nicholas P.Chironis.Mechanisms and Mechanical Devices SourcebookM.2007.2.11 Paul D Walker,Nong Zhang,Active damping of transient vibration in dual cluch transmission equipped powertrains:A comparison of conventional and hybrid electric vehiclesJ.Mechanism and Machine Theory,2014,77:11212 成大先.機械設(shè)計手冊第五版第一卷M.北京:化學工業(yè)出版社,2007.11.13 成大先.機械設(shè)計手冊第五版第二卷M.北京:化學工業(yè)出版社,2007.11.14 任濟生，唐道武，馬克新.機械設(shè)計課程設(shè)計M.徐州:中國礦業(yè)大學出版社,2008.08.l感謝語THANKYOU感謝母校提供了寶貴的學習與實踐的機會!感謝賀俊杰老師給與的耐心指導!感謝大學生活中的每一位!感謝各位答辯評審!感謝各位同學的支持與幫助!感謝觀看誠懇指正感謝觀看誠懇指正北華航天工業(yè)學院2017級機電工程學院 答辯人指導老師胡曉斌賀俊杰 本科生畢業(yè)設(shè)計 (論文) 外 文 翻 譯 原 文 標 題 Elevator System Based on PLC 譯 文 標 題 PLC控制下的電梯系統(tǒng) 作者所在系別 機電工程學院 作者所在專業(yè) 機械設(shè)計制造及自動化 作者所在班級 B13113 作 者 姓 名 胡曉斌 作 者 學 號 20134011306 指導教師姓名 賀俊杰 指導教師職稱 講師 完 成 時 間 2017 年 3 月 北華航天工業(yè)學院教務(wù)處制 譯文標題 PLC控制下的電梯系統(tǒng) 原文標題 Elevator System Based on PLC 作 者 Leonard Knox 譯 名 倫納德.諾克斯 國 籍 美國 原文出處 中國知網(wǎng)http://www.cnki.net/ 譯文： 由繼電器組成的順序控制系統(tǒng)是最早的一種實現(xiàn)電梯控制的方法。但是，進入九十年代，隨著科學技術(shù)的發(fā)展和計算機技術(shù)的廣泛應(yīng)用，人們對電梯的安全性、可靠性的要求越來越高，繼電器控制的弱點就越來越明顯。 電梯繼電器控制系統(tǒng)故障率高，大大降低了電梯的可靠性和安全性，經(jīng)常造成停梯，給乘用人員帶來不便和驚憂。且電梯一旦發(fā)生沖頂或蹲底，不但會造成電梯機械部件損壞，還可能出現(xiàn)人身事故。 可編程序控制器(PLC)最早是根據(jù)順序邏輯控制的需要而發(fā)展起來的，是專門為工業(yè)環(huán)境應(yīng)用而設(shè)計的數(shù)字運算操作的電子裝置。鑒于其種種優(yōu)點，目前，電梯的繼電器控制方式己逐漸被PLC控制所代替。同時，由于電機交流變頻調(diào)速技術(shù)的發(fā)展，電梯的拖動方式己由原來直流調(diào)速逐漸過渡到了交流變頻調(diào)速。因此，PLC控制技術(shù)加變頻調(diào)速技術(shù)己成為現(xiàn)代電梯行業(yè)的一個熱點。 1. PLC控制電梯的優(yōu)點： (1)在電梯控制中采用了PLC，用軟件實現(xiàn)對電梯運行的自動控制，可靠性大大提高。 (2)去掉了選層器及大部分繼電器，控制系統(tǒng)結(jié)構(gòu)簡單，外部線路簡化。 (3)PLC可實現(xiàn)各種復雜的控制系統(tǒng)，方便地增加或改變控制功能。 (4) PLC可進行故障自動檢測與報警顯示，提高運行安全性，并便于檢修。 (5)用于群控調(diào)配和管理，并提高電梯運行效率。 (6)更改控制方案時不需改動硬件接線。 2.電梯變頻調(diào)速控制的特點 隨著電力電子技術(shù)、微電子技術(shù)和計算機控制技術(shù)的飛速發(fā)展，交流變頻調(diào)速技術(shù)的發(fā)展也十分迅速。電動機交流變頻調(diào)速技術(shù)是當今節(jié)電、改善工藝流程以提高產(chǎn)品質(zhì)量和改善環(huán)境、推動技術(shù)進步的一種主要手段。變頻調(diào)速以其優(yōu)異的調(diào)速性能和起制動平穩(wěn)性能、高效率、高功率因數(shù)和節(jié)電效果，廣泛的適用范圍及其它許多優(yōu)點而被國內(nèi)外公認為最有發(fā)展前途的調(diào)速方式。 交流變頻調(diào)速電梯的特點： ⑴ 能源消耗低 ⑵ 電路負載低，所需緊急供電裝置小 在加速階段，所需起動電流小于2.5倍的額定電流。且起動電流峰值時間短。由于起動電流大幅度減小，故功耗和供電纜線直徑可減小很多。所需的緊急供電裝置的尺寸也比較小。 ⑶ 可靠性高，使用壽命長。 ⑷ 舒適感好 電梯運行是跟隨最佳給定的速度曲線運行的。其特性可適應(yīng)人體感受，并保證運行噪聲小，制動平穩(wěn) ⑸ 平層精度高 ⑹ 運行平穩(wěn)無噪聲 在轎廂內(nèi)，機房內(nèi)及鄰近區(qū)域確保噪聲小。因為其系統(tǒng)中采用了高時鐘頻率。始終產(chǎn)生一個不失真的正弦波供電電流。電動機不會出現(xiàn)轉(zhuǎn)距脈動。因此，消除了振動和噪聲。 3.電梯控制技術(shù) 所謂電梯控制技術(shù)是指電梯的傳動系統(tǒng)及操縱系統(tǒng)的電氣自動控制。作為我國20世紀70年代電梯的主要標志是交流雙速電梯。其調(diào)速方法是采用改變電梯牽引電動機的極對數(shù)，兩種或兩種不同級對數(shù)的繞組，其中極數(shù)少的繞組稱為高速繞組，極數(shù)多的繞組稱為低速繞組。高速繞組用于電梯的起動及穩(wěn)速運行，低速繞組用于制動及電梯的維修。 80年代初，VVVF變頻變壓系統(tǒng)控制的電梯問世。它采用交流電動機驅(qū)動，卻可以達到直流電動機的水平，目前控制速度已達6米/秒。它的體積小，重量輕，效率高，節(jié)省能源等幾乎包括了以往電梯的所有優(yōu)點。是目前最新的電梯拖動系統(tǒng)。 電梯在垂直運行過程中，有起點站也有終點站。對于三層樓以上的建筑物的電梯，起點站和終點站之間還沒有?？空荆瘘c站設(shè)在一樓，終點站設(shè)在最高樓。設(shè)在一樓的起點站稱為基站，起點站和終點站稱為兩端站，兩端站之間稱為中間站。 各站廳外設(shè)有召喚箱，箱上設(shè)置有供乘用人員召喚電梯用的召喚按鈕或觸鈕，一般電梯在兩端站的召喚箱上各設(shè)置一只按鈕或觸鈕。中間層站的召喚箱各設(shè)置兩只按鈕或觸鈕。對于無司機控制的電梯，在各層站的召喚箱上均設(shè)置一只按鈕或觸鈕。而電梯的轎廂內(nèi)部設(shè)置有（雜物電梯除外）操縱箱。操縱箱上設(shè)置有手柄開關(guān)或與層站對應(yīng)的按鈕或觸鈕，操縱箱上的按鈕或觸鈕城內(nèi)指令按鈕或觸鈕。外指令按鈕或觸鈕發(fā)出的電信號稱為外指令信號，內(nèi)指令按鈕或觸鈕發(fā)出的電信號成為內(nèi)指令信號。20世紀80年代中期后，觸鈕已被微動按鈕所取代。 作為電梯基站的廳外召喚箱，除設(shè)置一只召喚按鈕或觸鈕外，還設(shè)置一只鑰匙開關(guān)，以便下班關(guān)電梯時。司機或管理人員把電梯開到基站后，可以通過專用鑰匙扭動該鑰匙開關(guān)。把電梯的廳門關(guān)閉妥當后，自動切斷電梯控制電源或動力電源。 4. PLC控制電梯的設(shè)計 隨著城市建設(shè)的不斷發(fā)展，高層建筑不斷增多，電梯在國民經(jīng)濟和生活中有著廣泛的應(yīng)用。電梯作為高層建筑中垂直運行的交通工具已與人們的日常生活密不可分。實際上電梯是根據(jù)外部呼叫信號以及自身控制規(guī)律等運行的，而呼叫是隨機的，電梯實際上是一個人機交互式的控制系統(tǒng)，單純用順序控制或邏輯控制是不能滿足控制要求的，因此，電梯控制系統(tǒng)采用隨機邏輯方式控制。目前電梯的控制普遍采用了兩種方式，一是采用微機作為信號控制單元，完成電梯信號的采集、運行狀態(tài)和功能的設(shè)定，實現(xiàn)電梯的自動調(diào)度和集選運行功能，拖動控制則由變頻器來完成；第二種控制方式用可編程控制器（PLC）取代微機實現(xiàn)信號集選控制。從控制方式和性能上來說，這兩種方法并沒有太大的區(qū)別。國內(nèi)廠家大多選擇第二種方式，其原因在于生產(chǎn)規(guī)模較小，自己設(shè)計和制造微機控制裝置成本較高；而PLC可靠性高，程序設(shè)計方便靈活，抗干擾能力強、運行穩(wěn)定可靠等特點，所以現(xiàn)在的電梯控制系統(tǒng)廣泛采用可編程控制器來實現(xiàn)。 5.電梯控制系統(tǒng)特性 在電梯運行曲線中的啟動段是關(guān)系到電梯運行舒適感指標的主要環(huán)節(jié)，而舒適感又與加速度直接相關(guān)，根據(jù)控制理論，要使某個量按預定規(guī)律變化必須對其進行直接控制，對于電梯控制系統(tǒng)來說，要使加速度按理想曲線變化就必須采用加速度反饋，根據(jù)電動機的力矩方程式:M—MZ=ΔM=J（dn/dt），可見加速度的變化率反映了系統(tǒng)動態(tài)轉(zhuǎn)距的變化，控制加速度就控制系統(tǒng)的動態(tài)轉(zhuǎn)距ΔM=M—MZ。故在此段采用加速度的時間控制原則，當啟動上升段速度達到穩(wěn)態(tài)值的90%時，將系統(tǒng)由加速度控制切換到速度控制，因為在穩(wěn)速段，速度為恒值控制波動較小，加速度變化不大，且采用速度閉環(huán)控制可以使穩(wěn)態(tài)速度保持一定的精度，為制動段的精確平層創(chuàng)造條件。在系統(tǒng)的速度上升段和穩(wěn)速段雖都采用PI調(diào)節(jié)器控制，但兩段的PI參數(shù)是不同的，以提高系統(tǒng)的動態(tài)響應(yīng)指標。在系統(tǒng)的制動段，即要對減速度進行必要的控制，以保證舒適感，又要嚴格地按電梯運行的速度和距離的關(guān)系來控制，以保證平層的精度。在系統(tǒng)的轉(zhuǎn)速降至120r/min之前，為了使兩者得到兼顧，采取以加速度對時間控制為主，同時根據(jù)在每一制動距離上實際轉(zhuǎn)速與理論轉(zhuǎn)速的偏差來修正加速度給定曲線的方法。例如在距離平層點的某一距離L處，速度應(yīng)降為Vm/s，而實際轉(zhuǎn)速高為V′m/s，則說明所加的制動轉(zhuǎn)距不夠，因此計算出此處的給定減速度值-ag后，使其再加上一個負偏差ε，即使此處的減速度給定值修正為-（ag+ε）使給定減速度與實際速度負偏差加大，從而加大了制動轉(zhuǎn)距，使速度很快降到標準值，當電動機的轉(zhuǎn)速降到120r/min以后，此時轎廂距平層只有十幾厘米，電梯的運行速度很低，為防止未到平層區(qū)就停車的現(xiàn)象出現(xiàn)，以使電梯能較快地進入平層區(qū)，在此段采用比例調(diào)節(jié)，并采用時間優(yōu)化控制，以保證電梯準確及時地進入平層區(qū)，以達到準確可靠平層。 原文： Composed by the order of relay control system is a realization of the first elevator control method. However, to enter the nineties, with the development of science and technology and the widespread application of computer technology, the safety of elevators, reliability of the increasingly high demand on the relay control weaknesses are becoming evident. Elevator control system relays the failure rate high, greatly reduces the reliability and safety of elevators, and escalators stopped often to take with the staff about the inconvenience and fear. And the event rather than taking the lift or squat at the end of the lift will not only cause damage to mechanical components, but also personal accident may occur. Programmable Logic Controller (PLC) is the first order logic control in accordance with the needs of developed specifically for industrial environment applications to operate the electronic digital computing device. Given its advantages, at present, the relay control the lift has been gradually replaced by PLC control. At the same time, AC variable frequency motor speed control technology, the way the lift drag speed has been a gradual transition from DC to AC frequency converter. Thus, PLC control technology increases VVVF Elevator modern technology has become a hot industry. 1. PLC elevator control advantages (1) used in elevator control PLC, with software for automatic control of lift operation, reliability greatly increased. (2) layer was removed and a majority of the relay, the control system structure is simple, to simplify the external circuit. (3) PLC can be a variety of complex control system, easy to add or change control functions. (4) PLC can be automated fault detection and alarm display to improve the operation of security and ease of maintenance. (5) for the group control the allocation and management, and improve the efficiency of elevator operation. (6) do not need to change the control scheme changes when the hardware connection. 2. VVVF elevator control characteristics With the power electronics, microelectronics and computer technology to control the rapid development of technology, communication technology VVVF also a very rapid rate. AC variable frequency motor speed control technology is the power to improve the process in order to improve product quality and improving the environment and promoting technological progress as a primary means. Frequency of its excellent performance and the speed brake from a smooth performance, high efficiency, high power factor and power-saving effect of a broad scope of application and many other advantages of being at home and abroad recognized as the most promising approach speed. Exchange characteristics of VVVF Elevator (1)low energy consumption (2) low load circuit, the required emergency power supply device of small In the acceleration stage, the required start-up current of less than 2.5 times the rated current. Peak starting current and time is short. Since the starting current is drastically reduced, so power consumption and power supply cable diameter can be reduced a lot. Required for emergency power supply devices are also relatively small size. (3) high reliability and long service life. (4) good comfort Elevator operation is best to follow the speed curve of a given operation. Their characteristics can be adapted to human feelings, and to ensure that noise operation, smooth brake Ping layer and high precision (5) Stable noise-free (6) In the car, the engine room and adjacent areas to ensure that noise. Because their systems use a high clock frequency. Always produce a true sine wave power supply current yet. Motor torque ripple does not appear. Therefore, to eliminate vibration and noise. 3. Elevator control technology The so-called elevator control technology refers to the elevator drive system and electrical control system of automatic control. 70 as the 20th century in China's elevator was marked by the exchange of two-speed elevator. Its speed is used to change the elevator traction motor of the very few, two or multi-level approach to the number of windings, very few of them as high-speed winding of the winding, a very few number of windings as the low-speed winding. Windings for high-speed elevator-speed start-up and running, low-speed windings for braking and the maintenance of elevators. The early 80s, VVVF inverter controlled variable lift system available. It uses AC motor drives, are able to reach the level of DC motor, control the speed of the current has reached 6 m / sec. Its small size, light weight, high efficiency, energy saving, including the past almost all the advantages of the lift. Is the latest elevator drive system. Operation in vertical lift, there is also the starting point of the terminus station. For more than three-story elevator buildings, the starting point of the terminal stations and stops between the had not, the starting point for these stations at the first floor of the terminal located at the highest floor. Starting point in the first floor of the station known as base stations, known as the starting point at both ends of the terminal stations and stations at both ends of intermediate stops between stations. Outside the station has a call box, box set are used by staff for elevator call button or touch the call button, the general ends of the lift stations in the call box on the Settings button or touch of a button. Middle layer of the station set up the call box button or touch button 2. No drivers for the control of elevators, at various stations are set up calls me on a button or touch button. Elevator car and the internal settings (except for debris elevator) to manipulate me. Control box switch on the handle or set up stations and the corresponding layer of buttons or touch-button control box on the touch-control button or command button or touch the city button. Outside the command button or touch-button issue as the signal outside the command signal, within the command button or touch-button issue within the signal as a command signal. 80 In the mid-20th century, the touch button has been replaced by micro-button. As the elevator call box outside the base station, in addition to set up a call button or touch button, but also set a key switch in order to work the elevator clearance. Drivers or management staff to open the elevator to the base station can wriggle through a dedicated key to the key switch. Close the elevator in place to automatically cut off the elevator control power supply or power supply. 4. PLC Control Elevator Design With the continuous development of urban construction, the increasing high-rise buildings, elevators and life in the national economy has a broad application. Elevator high-rise buildings as a means of transport in the vertical run of daily life has been inextricably linked with people. In fact the lift is based on external call control signals, as well as the laws of their own, such as running, and the call is random, the lift is actually a man-machine interactive control system, simple to use control or logic control order can not meet the control requirements, and therefore , elevator control system uses a random control logic. Elevator control is currently generally used in two ways, first, the use of computer as a signal control unit, the completion of the lift signal acquisition, operation and function of the set, to achieve the lift and set the automatic scheduling function to run the election, drag the control from inverter to complete; the second control mode with programmable logic controller (PLC) to replace the computer control signal sets the election. From the control and performance, these two types of methods and there is no significant difference. Most of the domestic manufacturers to choose the second approach, because the smaller scale of production, their design and manufacture of high cost of computer control devices; and PLC high reliability, convenient and flexible program design, anti-interference ability, stable and reliable operation of the characteristics of Therefore, the elevator control system is now widely used to realize programmable controller. 5. Elevator control system characteristics Operation of the lift curve is above the start to run comfort indicators lift the key features, and comfort are directly related with the acceleration, according to control theory, for a certain amount of change according to the law must be directly controlled, for elevator control system, according to the ideal acceleration curve acceleration feedback to be used, in accordance with the motor torque equation: M-MZ = ΔM = J (dn / dt), can be seen reflected in the rate of change of acceleration of the system of dynamic torque changes on the control system to control the acceleration of the dynamic torque ΔM = M-MZ. Therefore, during this time to control the use of the principle of acceleration, when the start rate of increase in steady-state value above 90%, the acceleration control system by the switch to speed control, as in paragraph steady speed, speed control for the constant fluctuations in the smaller, little change in acceleration, speed and the use of closed-loop control can maintain a steady-state speed accuracy and precision for the braking section to create the conditions ping layer. Is rising at a rate in the system, and although the above-speed PI regulator used to control, but two of the PI parameters are different in order to improve the system dynamic response indicators. The brake in the system, that is, to reduce the speed of control necessary to ensure the comfort, but also strictly in accordance with the operation of the lift of the relationship between speed and distance control to ensure the accuracy of flat layers. To the speed in the system before 120r/min, in order to take into account both be taken to control the acceleration of time-based and at the same time in each braking distance based on actual speed and speed deviations from the theory to fix the acceleration curve of a given method. For example, from a flat layer at the distance L, the speed should be reduced to Vm / s, while the actual high speed V'm / s, is illustrated by the increase in the braking torque is not enough here, therefore to calculate value determined by the speed-ag after it combined with a negative deviation of ε, even here the value given by the speed of amended - (ag + ε) so that a given rate of deceleration and the actual increase of negative bias, which increases braking torque big, so fast down to the standard value, when the motor speed 120r/min down after the car at this time only a dozen or so cm layer anomaly, low speed lift, in order to prevent yet floor parking area on the phenomenon in order to enable faster access to the lift to floor area ratio adjustment used in this paragraph and the use of optimal control of time in order to ensure accurate and timely access to elevator floor area, in order to achieve accurate and reliable level layer. 指 導 教 師 評 語 外文翻譯成績： 指導教師簽字： 年 月 日 注：1. 指導教師對譯文進行評閱時應(yīng)注意以下幾個方面：①翻譯的外文文獻與畢業(yè)設(shè)計（論文）的主題是否高度相關(guān)，并作為外文參考文獻列入畢業(yè)設(shè)計（論文）的參考文獻；②翻譯的外文文獻字數(shù)是否達到規(guī)定數(shù)量（3 000字以上）；③譯文語言是否準確、通順、具有參考價值。 2. 外文原文應(yīng)以附件的方式置于譯文之后。