板料矯直機(jī)設(shè)計(jì)
板料矯直機(jī)設(shè)計(jì),板料,矯直機(jī),設(shè)計(jì)
本科生畢業(yè)設(shè)計(jì) (論文)
外 文 翻 譯
原 文 標(biāo) 題
AUTOMATING THE CONTROL OF MODERN Operated Melon Shelling Machine using Impact Technique of Manually and Motorized
Operated Melon Shelling Machine using Impact Technique
EQUIPMENT FOR STRAIGHTE
Operated Melon Shelling Machine using Impact Technique
NING FLAT-ROLLED PRODUCT
Technique
譯 文 標(biāo) 題
現(xiàn)代化矯直軋制薄品設(shè)備的自動(dòng)化控制
作者所在系別
機(jī)電工程學(xué)院
作者所在專業(yè)
機(jī)械設(shè)計(jì)制造及其自動(dòng)化
作者所在班級(jí)
B13113
作 者 姓 名
李海俠
作 者 學(xué) 號(hào)
20134011309
指導(dǎo)教師姓名
賀俊杰
指導(dǎo)教師職稱
講師
完 成 時(shí) 間
2017年3月
北華航天工業(yè)學(xué)院教務(wù)處制
譯文標(biāo)題
現(xiàn)代化矯直軋制薄品設(shè)備的自動(dòng)化控制
原文標(biāo)題
AUTOMATING THE CONTROL OF MODERN EQUIPMENT FOR STRAIGHTENING FLAT-ROLLED PRODUCT
作 者
YN Belobrov,
VG Smirnov,
AI Titarenko,
譯 名
百倫布若
國(guó) 籍
美國(guó)
原文出處
Mechanical Engineering Department, Faculty of Engineering and Technology University of Ilorin, P.M.B. 1515, Ilorin, Nigeria.Received 13 December 2008; Accepted 23 February 2009
譯文：
謝韋爾鋼鐵公司在2003年8月成功完成了新引進(jìn)的規(guī)格為2800—5000米爾的直線式鋼板矯直機(jī)（平臺(tái)相關(guān)模型）。機(jī)器的主要設(shè)計(jì)特點(diǎn)如下：
l 每臺(tái)機(jī)器配備液壓緊固裝置(用于改善機(jī)器的動(dòng)力學(xué)性能和調(diào)整的準(zhǔn)確性以及更可靠地保持恒定的間隙)
l 每臺(tái)機(jī)器都有能在液壓缸的輔助下分別調(diào)節(jié)每根工作輥的機(jī)構(gòu)(通過提供一種控制鋼板的曲率變化的方法來實(shí)現(xiàn)拓寬矯直范圍的目的)。
l 每個(gè)工作輥具有它自己的調(diào)節(jié)驅(qū)動(dòng)(去除主軸之間的剛性運(yùn)動(dòng)學(xué)制約）
l 該系統(tǒng)平臺(tái)相關(guān)模型的輥軸是封裝在封閉箱（錄音帶）中的(便于維修,降低替換輥的成本)
l 這個(gè)模型有一個(gè)系統(tǒng),它可用于調(diào)整機(jī)器從九輥矯直方案轉(zhuǎn)變?yōu)槲遢伋C直方案，過程輥間的距離增加了一倍(這是為了擴(kuò)大機(jī)器對(duì)板厚度的可允許范圍)。
因此,新的矯直機(jī)是一個(gè)多功能、復(fù)雜的機(jī)器,其包括一個(gè)可由數(shù)字和模擬信號(hào)控制的寬范圍、電驅(qū)動(dòng)元件的液壓組件。整個(gè)復(fù)雜的機(jī)構(gòu)可以分為兩個(gè)功能機(jī)體：主要的機(jī)體,包括直接參與矯直操作的機(jī)構(gòu)(其夾緊裝置能獨(dú)立適應(yīng)軋輥,調(diào)整組件以適應(yīng)不同的矯直要求,可移動(dòng)支線和主傳動(dòng)裝置的上輥) ；輔助裝置(包括盒式替代裝置、主軸鎖定機(jī)構(gòu)、輥軸支架設(shè)備冷卻系統(tǒng))。雖然平臺(tái)相關(guān)模型有大量的機(jī)制,運(yùn)用現(xiàn)代液壓和電氣驅(qū)動(dòng)，能夠在平臺(tái)相關(guān)模型和其運(yùn)轉(zhuǎn)機(jī)構(gòu)上幾乎完全的實(shí)現(xiàn)對(duì)主要和輔助機(jī)構(gòu)的自動(dòng)化控制操作。
下面描述的是薄板矯直機(jī)的特點(diǎn)以及自動(dòng)控制系統(tǒng)的最重要的機(jī)理，同時(shí)對(duì)操作機(jī)理也進(jìn)行了探討。
薄板矯直機(jī)的液壓緊固機(jī)構(gòu)(HHMs)功能在于兩大系統(tǒng):調(diào)整系統(tǒng)；指定位置的維護(hù)系統(tǒng)。對(duì)控制系統(tǒng)和某些有效條件系統(tǒng)存在一定的要求。
在液壓緊固機(jī)構(gòu)的調(diào)整系統(tǒng)、控制系統(tǒng),必須做到以下幾點(diǎn)：
l 液壓缸的同步運(yùn)動(dòng)保持，角偏轉(zhuǎn)到規(guī)定的限量以內(nèi)；
l 為適應(yīng)新板的尺寸的最大調(diào)整速度；
l 保持高的定位精度的機(jī)制；
該控制系統(tǒng)在維護(hù)系統(tǒng)操作時(shí)具有以下要求：
l 使封閉箱的（錄音帶）附件保持穩(wěn)定，同時(shí)保證給料機(jī)的上輥具有較高的準(zhǔn)確性；
l 當(dāng)偏差出現(xiàn)時(shí)，最大限度地減少設(shè)備返還到約定坐標(biāo)所需的時(shí)間(例如金屬板由于被矯直時(shí)而顯現(xiàn)出的彈力)。
同步需求。根據(jù)謝韋爾鋼鐵集團(tuán)3號(hào)金屬板矯直機(jī)組得出的操作經(jīng)驗(yàn),調(diào)整機(jī)器時(shí)最不確定的因素是因?yàn)閼?yīng)用液壓缸兒產(chǎn)生的不均勻力。這種非均勻性是由平臺(tái)模型上大部分活動(dòng)部件不對(duì)稱分布所引起的（特別是主軸裝配時(shí)的偏重效應(yīng)）。伺服閥的“液壓零點(diǎn)”與“電氣零點(diǎn)”的相對(duì)位移也是一個(gè)因素。液壓缸的體積越小后者越重要。因此，給料機(jī)上輥的HHM的零點(diǎn)漂移是最敏感的。
也有其他因素的影響,同時(shí)性, 緊固機(jī)制的同步運(yùn)行：
l 液壓缸上部分區(qū)域的摩擦力的差別源于成對(duì)零件的規(guī)模大小的組合差異，即使偏差非常的??；
l “彈起”差異特征和液壓供應(yīng)渠道的慣性表征指標(biāo)(由于液壓缸的伺服閥不同長(zhǎng)度管的入口)。
因此,即使模型上沒有配置機(jī)械地保持液壓缸操作同步的裝置, 伺服閥的相同振幅信號(hào)的傳輸?shù)妮斎氩豢杀苊鈱?dǎo)致一個(gè)嚴(yán)重危害機(jī)器的速差。
對(duì)降低及消除上述因素的影響,研制出一種對(duì)緊固機(jī)制進(jìn)行電氣同步的算法。
包括四個(gè)緊固缸、四個(gè)平衡缸的封閉箱頂部的HHM,是為保證機(jī)器的靈活的調(diào)整設(shè)定所需尺寸的矯直差(按照板的厚度),并通過現(xiàn)有的準(zhǔn)確性和遮蔽物上矯直力的符合缺乏來維持這個(gè)精度范圍。液壓系統(tǒng)的緊固機(jī)制設(shè)計(jì)是這樣一種方式,只有一室的液壓缸,是用來作為工作室。第二室總是與排泄通道相連。平衡力量被緊固氣缸克服時(shí)封閉箱降低頂端的。只有在氣缸平衡時(shí)封閉箱才提起。這樣的布置可以消除精度范圍在設(shè)備上的影響。
頂部的HHM的輥的支線由兩個(gè)液壓缸組成。當(dāng)輥被提升的同時(shí)，輥降低和油液輸入桿腔，液柱塞腔被注入液油。
控制原則。特有電路如圖所示(圖1),來控緊固機(jī)制的液壓缸。伺服閥輸入端的控制信號(hào)（Xctl）是由一個(gè)比例-積分(PI)控制器傳遞的(為了提高靈系統(tǒng)的敏度,我們選擇了用瓣膜,以“零”觸發(fā))。輸入信號(hào)（錯(cuò)誤信號(hào)Xerr）發(fā)送到控制器的輸入端后形成位置（Xcpt）和反饋信號(hào)的要點(diǎn)控制信號(hào)（Xf.b），后續(xù)信號(hào)是從所給液壓缸的直線位移軌距（G）接收的。
密封箱頂部的HHM的標(biāo)定測(cè)量頭組成了平衡液壓缸(HCs)。氣瓶是安裝了這樣一種方式,他們的動(dòng)作可以被認(rèn)為是等于位移相應(yīng)圓柱棒、與津貼為某些系數(shù)。支線上輥的HHM的測(cè)量頭組成了緊固氣瓶。
該控制器的不可分割的組成部分,僅在最后被激活時(shí)調(diào)整階段和穩(wěn)定規(guī)定的坐標(biāo)。當(dāng)位移超過一定閾值,PI控制器的功能是被一個(gè)比例(P)控制器的傳遞函數(shù)所代替的W(s)= k。因此,Xctl(t)= kXerr(t)。
當(dāng)有工作中的輥?zhàn)佑蟹浅ｏ@著的差異時(shí),這其中之間的關(guān)鍵控制點(diǎn)和反饋信號(hào)的區(qū)別(誤差)從直線位測(cè)量達(dá)到足夠大,這樣值輸出信號(hào)控制伺服閥的操作達(dá)到飽和區(qū)。在這種情況下,進(jìn)一步位移、速度和同步動(dòng)作的規(guī)定,這樣當(dāng)誤差超過范圍時(shí)氣缸的同步移動(dòng)變得不可能，這時(shí)Xctl大于飽和區(qū)的邊值問題(Xsat)。
通過減少k來解決特定的問題導(dǎo)致了在調(diào)整PSM時(shí)的速度損失和矯直機(jī)的操作中控制精度的降低。因此,為了保持控制信號(hào)到達(dá)飽和區(qū)當(dāng)有大的位移、整個(gè)系統(tǒng)的設(shè)計(jì)，這樣的輸入端控制器并不是實(shí)際的所需值（Xrq),但增量(?X)是巨大的，k ?X < Xsat 這樣的狀況是令人滿意的。液壓缸的位置變化后，控制點(diǎn)的增加取決于?X的大小，其與相對(duì)于圓柱的運(yùn)動(dòng)方向相應(yīng)的有最大的滯后量有關(guān)。調(diào)整的關(guān)鍵控制點(diǎn)維持現(xiàn)狀，直到所需要求和裝置的實(shí)際位置之間的差異小于其增量：Xrq – Xf.b < ?X。
然后控制器的輸入適應(yīng)其增值Xcpt，相當(dāng)于調(diào)整要求：Xcpt= Xrq。調(diào)整如此完成。
使用的原則是一步幾乎對(duì)所有的理想重復(fù)的因素而言，增加控制點(diǎn)使人們有可能同步運(yùn)動(dòng)的汽缸和設(shè)置的關(guān)鍵控制點(diǎn)以高度的準(zhǔn)確性。獨(dú)特的調(diào)整機(jī)制工作輥。平板矯直機(jī)如此設(shè)計(jì)通過借助于V-belt驅(qū)動(dòng)液壓缸動(dòng)作來實(shí)現(xiàn)每個(gè)工作輥可以移動(dòng)垂直。通過操作與比例伺服閥的控制來提供液壓缸的動(dòng)力。線性位移測(cè)量器設(shè)置在每一個(gè)液壓缸上獲得輥的位置反饋信號(hào)。由于這些測(cè)量頭實(shí)際上是傳遞著液壓拉桿的位置信息而不是工作輥本身，在接下來的轉(zhuǎn)換中來得到坐標(biāo)：kred驅(qū)使齒輪d動(dòng)比;Xf.b是通過直線位移傳感器測(cè)量的柱桿位置。
因此,位置反饋電路反應(yīng)了各項(xiàng)工作輥的姿態(tài)控制。圖1為電路圖。
控制信號(hào)產(chǎn)生采用PI控制器,它使得人們有可能達(dá)到了高度的調(diào)節(jié)系統(tǒng)的預(yù)測(cè)精度而不損失速度。
獨(dú)立驅(qū)動(dòng)的輥?zhàn)?。這四種設(shè)計(jì)是基于使用獨(dú)立驅(qū)動(dòng)的交流電機(jī)，其分別采用了不同動(dòng)力反饋的變頻器。每一個(gè)單獨(dú)的驅(qū)動(dòng)提供了以下一種優(yōu)于集中驅(qū)動(dòng):
l 由于在組件的機(jī)制中存在著線性工作輥和速度板之間速度不同的這種可能性；
l 如果一個(gè)乃至幾個(gè)驅(qū)動(dòng)器出現(xiàn)故障，這臺(tái)機(jī)器可以繼續(xù)操作，但在這種情況下,相應(yīng)的矯直輥的驅(qū)動(dòng)將會(huì)被停止；
l 輥?zhàn)拥木€性速度的可能性滾筒可單獨(dú)按照矯獨(dú)有的直板進(jìn)給的實(shí)際速度；
l 輥?zhàn)拥木€速度按照實(shí)際板材的速度進(jìn)行更正成為可能,其速度可以進(jìn)行一個(gè)修正或者作為一個(gè)初步調(diào)整措施；
l 這樣的修正作為一個(gè)初步措施（在測(cè)量和理論計(jì)算的基礎(chǔ)上)或在矯直機(jī)的實(shí)際操作中(在操作中獲得的數(shù)據(jù)和采用變頻調(diào)速器實(shí)現(xiàn)人工智能的基礎(chǔ)上)。
矯直機(jī)的主傳動(dòng)為的矯直機(jī)九個(gè)矯直輥與兩個(gè)輔助輥。該驅(qū)動(dòng)必須在操作中高度可靠,如果驅(qū)動(dòng)不能正常工作甚至持續(xù)很短的一段時(shí)間，意味著軋機(jī)生產(chǎn)線的生產(chǎn)量可能會(huì)招致?lián)p失。
驅(qū)動(dòng)所必須滿足的要求決定于機(jī)器整體的操作和設(shè)備的設(shè)計(jì)特點(diǎn)：
l 板材被矯直就必須在矯直機(jī)的下輥、上輥和相鄰輸送輥之間創(chuàng)造一個(gè)剛性運(yùn)動(dòng)耦合關(guān)系的；
l 板材應(yīng)該承受到矯直機(jī)矯直操作中所導(dǎo)致的伸長(zhǎng)塑性變形,伸長(zhǎng)長(zhǎng)度的不同增加是因?yàn)槊總€(gè)工作輥彎曲半徑的分化；這種情況導(dǎo)致了當(dāng)板材移動(dòng)快到PSM的末端時(shí)速度的不均勻增加；
l 必須使使用不同直徑的工作輥成為可能(這是必須的,比如說,由于不均勻磨損)；
l 負(fù)載輥應(yīng)依照選擇而分化矯直體系；
l 反向矯直應(yīng)當(dāng)是可行的。
l 根據(jù)上述因素以及實(shí)際操作的體系板材矯直機(jī)正在被研制在這里,下列要求建立電力驅(qū)動(dòng):
l 廣泛的范圍內(nèi)規(guī)定的速度,包括啟動(dòng)馬達(dá)在荷載作用下；
l 在逆向體系中的運(yùn)行；
l 一個(gè)剛性的特點(diǎn)ω = ?(M)；
l 在保持規(guī)定的速度中有高度的準(zhǔn)確性；
l 完全同步操作。
要求操作者顯示想要的位置的底部(5 -或9輥?zhàn)觢矯直);調(diào)整頂部和底部的間距;為工作輥?zhàn)拥膫€(gè)別調(diào)整設(shè)定坐標(biāo),選擇的矯直速度和方向;產(chǎn)生一個(gè)命令給機(jī)器開始調(diào)整到指定的機(jī)構(gòu)。
這機(jī)器是自動(dòng)適應(yīng)所選擇的機(jī)構(gòu)。調(diào)整完成后時(shí),一個(gè)信號(hào)發(fā)送給控制面板顯示的坐標(biāo)的狀態(tài)發(fā)生了變化,預(yù)示這些已經(jīng)達(dá)到他們的滾筒規(guī)定的工作速度。
在自動(dòng)變量中、板式矯直機(jī)是為基礎(chǔ)調(diào)整的數(shù)據(jù)發(fā)送通過數(shù)據(jù)網(wǎng)絡(luò)從更高水平的系統(tǒng)。這些數(shù)據(jù)包括下列事項(xiàng):
l 被矯直板的厚度;
l 鋼的組別 (物質(zhì)比例的信息);
l Psm入口的溫度;
l PSM調(diào)整分幾個(gè)階段:
l 初步調(diào)整基于鋼板厚度及鋼鐵的種類,為冷軋鋼板(t = 20°C);
l 基于安裝在距psm50m的高溫計(jì)獲得的數(shù)據(jù)作進(jìn)一步調(diào)整;
l 基于安裝在機(jī)器入口的高溫計(jì)做最終調(diào)整;
l 在自動(dòng)變量控制輥輸送毗鄰機(jī)是轉(zhuǎn)向了控制。
系統(tǒng)的詩(shī)作為下一盤方法這臺(tái)機(jī)器。在這種情況,該盤直到及其調(diào)整完成才能進(jìn)入工作區(qū)域。如果有必要板通過機(jī)器沒有矯直它,本機(jī)完全改變到運(yùn)輸?shù)臓顟B(tài)。在這種情況下,頂端的橫木與黑盒將以規(guī)定的數(shù)量被提升并且輥?zhàn)拥乃俣缺桓淖?以致于它的速度等于相鄰輥輸送線。
磁帶替換機(jī)制將被應(yīng)用在輥?zhàn)訐p壞的情況或有必要再研磨工作輥和后排輥,在這種情況下,操作者能控制輔助機(jī)制的運(yùn)行:主軸鎖定機(jī)制、滾動(dòng)式推車、底部的機(jī)制,鎖住底部錄音帶和車?yán)锏奈恢?推動(dòng)車的液壓缸。
通過非接觸傳感器固定機(jī)器的位置。PSM控制系統(tǒng)。板式矯直機(jī)的控制要求一種功能強(qiáng)大的、高能力體系的開發(fā),該體系可以提供需要的控制精度與快速的運(yùn)轉(zhuǎn)相結(jié)合。
該控制系統(tǒng)分為兩個(gè)層次:基層,和一個(gè)上層。診斷系統(tǒng)作為一個(gè)獨(dú)立的系統(tǒng)創(chuàng)建。第二個(gè)控制器對(duì)PSM的控制泵站進(jìn)行控制。
基層的控制系統(tǒng)采用一種西門子系列S7的可編程工業(yè)控制器,而上層和診斷系統(tǒng)建立在標(biāo)準(zhǔn)電腦的基礎(chǔ)上。用于上層系統(tǒng)的計(jì)算機(jī)也作為PSM的控制面板。
不同要素的控制系統(tǒng)由兩圈連接的PROFIBUS網(wǎng)絡(luò)來連接，如圖3所示。第一個(gè)循環(huán)的功能是作為控制器、上層計(jì)算機(jī)、診斷站以及pump-station控制器之間的通信連接。第二個(gè)循環(huán)把PSM控制器和系統(tǒng)的功能元素連接起來（即頻率轉(zhuǎn)換器，線性位移量具和遠(yuǎn)程輸入輸出模塊）。
基于以下準(zhǔn)則，將控制系統(tǒng)的功能在基層和上層區(qū)分開來：基層承擔(dān)涉及從傳感器接收數(shù)據(jù)的機(jī)制安裝、從自動(dòng)過程控制系統(tǒng)板上獲取即將矯直的信息、為執(zhí)行機(jī)構(gòu)產(chǎn)生和傳輸控制信號(hào)（執(zhí)行器）的功能；上層承擔(dān)控制要點(diǎn)的歸檔以及監(jiān)控控制面板操作的功能。
以下特定功能是由基層的自動(dòng)化系統(tǒng)來執(zhí)行的：
l 從上層系統(tǒng)獲取指定的矯直參數(shù)（輥?zhàn)愚D(zhuǎn)速，頂部橫臂的坐標(biāo)，輥?zhàn)酉鄬?duì)于橫臂的坐標(biāo)）；
l 處理參數(shù)，給執(zhí)行機(jī)構(gòu)發(fā)送相應(yīng)的控制信號(hào)；
l 從安裝在機(jī)制上的傳感器獲取信息來決定PSM是否正確安裝以及是否為矯直機(jī)操作做 好準(zhǔn)備。
l 從安裝在機(jī)制上的反饋?zhàn)兯推鳙@取信息來估算控制措施；
l 分析傳感器讀數(shù)來決定數(shù)據(jù)的準(zhǔn)確性；
l 與PSM泵電池站（PBS）進(jìn)行數(shù)據(jù)交換，并發(fā)射站的運(yùn)行參數(shù)到到上一級(jí)以進(jìn)行顯示。
表1 平板矯直機(jī)的機(jī)器規(guī)格
參數(shù)
機(jī)器型號(hào)
LPM 2800
LPM 5000
厚度，mm
寬度，mm
長(zhǎng)度，mm
板材最大屈服點(diǎn)，MPa
矯直速度，m/sec
矯直力，MN
矯直后鋼板殘余曲率(在整個(gè)厚度范圍),mm/m
7–60
1500–2700
from 5000
≤850
0.3–0.6
30.0
≤3.0
10–100
1500–4800
from 8000
≤1250
0.2–0.6
50.0
≤3.0
l 從上一級(jí)系統(tǒng)獲得初始數(shù)據(jù)進(jìn)行自動(dòng)校正和數(shù)據(jù)傳輸以便進(jìn)行適當(dāng)?shù)恼{(diào)整。
上一級(jí)自動(dòng)化系統(tǒng)的功能如下：
l 在矯直管理系統(tǒng)中輸入數(shù)據(jù)以便隨后進(jìn)行狀態(tài)選擇，并將信息錄入數(shù)據(jù)庫(kù)中；
l 從數(shù)據(jù)庫(kù)中手動(dòng)選擇矯直狀態(tài)以選擇相應(yīng)板材（這個(gè)由操作者完成）；
l 在從上一級(jí)系統(tǒng)中獲得信息的基礎(chǔ)上，從數(shù)據(jù)庫(kù)中自動(dòng)選擇矯正狀態(tài)；
l 在矯正和盒子替換過程中進(jìn)行手動(dòng)控制機(jī)器表明機(jī)構(gòu)定位的根據(jù)是傳感器和限位開關(guān)的位置讀數(shù)；
l 表明一個(gè)金屬板存在于PSM的工作區(qū)；
l 表明金屬板的溫度是由高溫計(jì)測(cè)量得到的；
l 視覺代表矯直系統(tǒng)和機(jī)器調(diào)整；
l 視覺代表機(jī)器結(jié)構(gòu)和PBS的情況以用于診斷目的；
l 遠(yuǎn)程輸入輸出模塊ET200是用來為未校準(zhǔn)的驅(qū)動(dòng)裝置供電。立柜中包括繼電器和接口，因?yàn)檫@些驅(qū)動(dòng)器距離控制者有相當(dāng)長(zhǎng)的一段距離。該模塊的應(yīng)用，使電纜長(zhǎng)度的有效縮短成為可能。
診斷系統(tǒng)。高濃度的電器及液壓設(shè)備中包括類似PSM設(shè)備的一部分，這些設(shè)備與機(jī)器本身有一段距離，并且常常是難以到達(dá)的地方，這使之更難以為機(jī)器提供服務(wù)和尋找問題根源。為方便PSM的保養(yǎng)和維修時(shí)間的縮短，必須建立一個(gè)先進(jìn)的診斷系統(tǒng)。
該系統(tǒng)是基于安裝在控制崗位的工業(yè)控制計(jì)算機(jī)。它診斷PSM各種機(jī)構(gòu)，以及它的液壓和電氣設(shè)備的狀態(tài)。該系統(tǒng)可用于評(píng)估的自動(dòng)開關(guān)的條件下，電機(jī)的溫度傳感器，線性位移計(jì)，當(dāng)?shù)豍ROFIBUS網(wǎng)絡(luò)終端，電流，速度和電機(jī)的旋轉(zhuǎn)方向，以及其他設(shè)備和參數(shù).
診斷系統(tǒng)也可用于建立的PSM的操作協(xié)議。其文件包括即時(shí)的數(shù)據(jù)和錯(cuò)誤的類型和發(fā)生故障的設(shè)備，機(jī)構(gòu)的坐標(biāo)，電機(jī)電流和速度，以及其他信息。
為了使控制系統(tǒng)更可靠，診斷臺(tái)的軟件和硬件與?控制系統(tǒng)的上一級(jí)相應(yīng)的組件相對(duì)應(yīng)。當(dāng)電腦控制操作發(fā)生問題時(shí)，?PSM的控制功能可以轉(zhuǎn)移到診斷系統(tǒng)的計(jì)算機(jī)上面。
?結(jié)論，NKMZ曾與獨(dú)立國(guó)家聯(lián)合體（獨(dú)聯(lián)體）的創(chuàng)始伙伴合作，成功地引進(jìn)了裝有現(xiàn)代自動(dòng)化控制系統(tǒng)的板矯正機(jī)。
使用機(jī)器使人們有可能減少或者幾乎完全消除成品板質(zhì)量對(duì)機(jī)床操作人員技能的依賴。?
控制系統(tǒng)，連同其方便的用戶界面，讓即使沒有受過專門培訓(xùn)的人迅速掌握機(jī)器的操作。?高品質(zhì)的產(chǎn)品的生產(chǎn)是在機(jī)器的運(yùn)動(dòng)機(jī)制保證下的確切結(jié)果?，并且其位置精確度也由其得到保證，這得益于具有比例控制和特殊控制算法的精密設(shè)備。?
此外，該機(jī)配備了先進(jìn)的診斷系統(tǒng)，它也記錄關(guān)鍵?參數(shù)。該系統(tǒng)可方便機(jī)器的許多復(fù)雜的零部件的維修和保養(yǎng)。
原文：
The company Severstal’ completed the successful introduction of new in-line plate-straightening machines (PSMs) on its 2800 and 5000 mills in August 2003 [1, 2, 3]. The main design features of the machines are as follows:
l each machine is equipped with hydraulic hold-down mechanisms (to improve the dynamics and accuracy of the machine adjustments and more reliably maintain a constant gap);
l the machines have mechanisms to individually adjust each work roller with the aid of hydraulic cylinders (this broadens the range of straightening regimes that can be realized by providing a measure of control over the change in the curvature of the plate);
l each work roller is provided with its own adjustable drive (to eliminate rigid kinematic constraints between the spindles);
l the system of rollers of the PSM is enclosed in cassettes (to facilitate repairs and reduce roller replacement costs);
l the PSM has a system that can be used to adjust the machine from a nine-roller straightening scheme to a five-
l roller scheme in which the distance between the rollers is doubled (this is done to widen the range of plate thick-nesses that the machine can accomodate).
Thus, the new straightening machine is a sophisticated multi-function system of mechanisms that includes a wide range of hydraulically and electrically driven components controlled by digital and analog signals. The entire complex of PSM mechanisms can be divided into two functional groups: the main group, which includes the mechanisms that partici-pate directly in the straightening operation (the hold-down mechanisms, the mechanisms that individually adjust the rollers,the mechanisms that adjust the components for different straightening regimes, the mechanism that moves the top roller of the feeder, and the main drive); the auxiliary group (which includes the cassette replacement mechanism, the spindle-lock-ing mechanism, and the equipment that cools the system of rollers). Although the PSM has a large number of mechanisms,the use of modern hydraulic and electric drives has made it possible to almost completely automate the main and auxiliary operations performed on the PSM and the units that operate with it.
Described below are the features and the automatic control systems for the most important mechanisms of the plate-straightening machine.The operating regimes of those mechanisms are also discussed.The hydraulic hold-down mechanisms (HHMs) of the sheet-straightening machine function in two main regimes:the adjustment regime;the regime in which the specified positions are maintained.There are certain requirements for the control system and certain efficiency criteria for each regime.
In the adjustment regime, the control system for the hydraulic hold-down mechanisms must do the following:
l synchronize the movements of the hydraulic cylinders and keep the angular deeflection within prescribed limits;
l maximize speed in adjusting the machine for a new plate size;
l maintain a high degree of accuracy in positioning the mechanisms;
The control system has the following requirements when operating in the maintenance regime:
l stabilize the coordinates of the top cassette and the top roller of the feeder with a high degree of accuracy;
l minimize the time needed to return the equipment to the prescribed coordinates when deviations occur (such as due to the force exerted by a plate being straightened).
Need for synchronization. Experience in operating the plate-straightening machine in plate shop No. 3 at Severstal’ has shown that the most problematic factor in adjusting the machine is the nonuniformity of the forces applied to the hydraulic cylinders. This nonuniformity is due to the asymmetric distribution of the masses of the moving parts of the PSM (in particular, the effect of the weight of the spindle assembly). Displacement of the “hydraulic zero point” relative to the “electrical zero point” in the servo valves is also a contributing factor.The latter reason is more significant, the smaller the volume of the hydraulic cylinder.Thus, the HHM of the top roller of the feeder is the most sensitive to drift of the zero point.
There are also other factors that affect the dynamism,simultaneousness,and synchronism of the operation of the hold-down mechanisms:
l differentiation of the frictional forces on parts of the hydraulic cylinders due to different combinations of deviations in the dimensions of the mated parts, despite the narrow tolerances;
l differences in the “springing” characteristics and the indices characterizing the inertia of the hydraulic supply channels (due to differences in the lengths of the pipes leading from the servo valves to the hydraulic cylinders).
Thus, since the PSM is not equipped with devices to mechanically synchronize the operation of the cylinders, the ransmission of signals of the same amplitude to the inputs of the servo valves inevitably results in a speed difference that can seriously damage the mechanisms.
To minimize and eliminate the effects of the above-mentioned factors, we developed an algorithm for electrical synchronization of the hold-down mechanisms.
The HHM of the top cassette, composed of four hold-down cylinders and four balancing cylinders, is designed to ensure
mobile adjustment of the machine to set the required size of straightening gap (in accordance with the thickness of the plate) and
maintain that gap with a specified accuracy in the presence .
and absence of a load on the housings from the straightening force.
The hydraulic system of the hold-down mechanism is designed in such a way that only one chamber of the hydraulic cylinders is used as the working chamber.The second chamber is always connected to the discharge channel.The top cassette is lowered when the balancing forces are overcome by the hold-down cylinders.The cassette is raised only by the action of the balancing cylinders.This arrangement has made it possible to eliminate gaps in the positioning of the equipment.
The HHM of the top roller of the feeder consists of two hydraulic cylinders. Hydraulic fluid is fed into the plunger chamber when the roller is to be lowered and is fed into the rod chamber when it is to be raised.
Control Principles. Individual circuits have been provided (Fig.1) to control the hydraulic cylinders of the hold-down mechanisms.The control signal (Xctl) sent to the input of the servo valve is formed by a proportional-integral (PI) controller (to improve the sensitivity of the system, we chose to use valves with “zero” overlap).The signal sent to the input of the controller (the error signal Xerr) is formed as the difference between the control-point signal for position (Xcpt) and the feedback signal (Xf.b).The latter signal is received from the linear displacement gage (G) of the given hydraulic cylinder.
The gages of the HHM for the top cassette are built into the balancing hydraulic cylinders (HCs).The cylinders are installed in such a way that their movements can be considered to be equal to the displacements of the corresponding cylinder rods, with allowance for certain coefficients.The gages in the HHM for the top roller of the feeder are incorporated directly into the hold-down cylinders.
The integral part of the controller is activated only during the final adjustment stage and during stabilization of the prescribed coordinate.When the displacements exceed a certain threshold value, the functions of the PI controller are taken over by a proportional (P) controller with the transfer function W(s) = k.Thus, Xctl(t) = kXerr(t).
When there are significant differences between the displacements of the working rollers,the difference (error)between the control point and the feedback signal from the linear displacement gage reaches values great enough so that the output signal which controls the operation of the servo valve reaches the saturation zone.In this case, further regulation of the displacement rate and,thus synchronization of the movements of the cylinders becomes impossible as long as the error exceeds the value at which Xctl is greater than the boundary value for the saturation zone (Xsat).The limiting error–the largest error for which Xctldoes not reach saturation–is inversely proportional to the gain of the controller k: Xerr< Xsat/ k.
Solving the given problem by decreasing k leads to a loss of speed in the adjustment of the PSM and a decrease in control accuracy during the straightening operation.Thus, to keep the control signal from reaching the saturation zone when there are substantial displacements, the system was designed so that the input of the controller is fed not the actual required value (Xrq) but an increment (?X) of a magnitude such that the condition k?X < Xsat is satisfied.The control point is increased by the amount ?X after the position of the cylinder has been changed by the amount corresponding to the increment having the largest lag relative to the cylinder’s direction of motion. The adjustment of the control point is continued until the difference between the required value and the actual position of the mechanism becomes less than the increment:Xrq – Xf.b < ?X.
Then the input of the controller is fed the value Xcpt, which is equal to the required adjustment: Xcpt= Xrq.The adjustment is thus completed.
Use of the principle of a stepped increase in the control point makes it possible synchronize the movements of the cylinders and set the control point with a high degree of accuracy for almost any ideal repetition factor.
Mechanisms for Individual Adjustment of the Working Rollers.The plate-straightening machine is designed so that each working roller can be moved vertically, which is done by means of a hydraulic cylinder acting in concert with a V-belt drive.The cylinders are supplied with power from servo valves operated with proportional control.A linear displacement gage is built into each cylinder to obtain a feedback signal on the position of the roller.Since these gages are actually transmiting
information on the position of the cylinder rods rather than the working rollers themselves, the following conversion is performed to obtain the rollers’ coordinates:
Xrol= kredXf.b,
where kred is the gear ratio of the drive;Xf.b is the position of the cylinder rod measured by the linear displacement transducers.
Thus, a position feedback circuit is provided to control the position of each working roller. Figure 1 presents a diagram of one of the circuits.
The control signals are generated by means of the PI controllere, which has made it possible to achieve a high degree of accuracy in adjusting the system without sacrificing speed.
The individual drive of the rollers. The above-described design is based on the use of individual ac drives with motors of different powers fed from frequency converters. Each individual drive offers the following advantages over a group drive:
l greater reliability thanks to the absence of additional loads on the components of the mechanisms due to differences between the linear velocities of the working rollers and the speed of the plate;
l the possibility that the machine could continue to operate if one or even several drives malfunction;in this case,the corresponding rollers would be removed from the straightening zone;
l the possibility that the linear velocities of the rollers could be individually corrected in accordance with the actual speed of the plate;such a correction could be made either as a preliminary measure (on the basis of measured and calculated values) or during the straightening operation (on the basis of the data obtained from the frequency converters, which employ artificial intelligence).
The main drive of the straightening machine rotates nine straightening rollers and two housing rollers.This drive must be highly reliable in operation, since the fact that the PSM is installed in the mill line means that sizable production losses can be incurred if the drive fails to work properly even for a short period of time.
The requirements that must be satisfied by the drive are determined by the operational and design features of the machine as a whole:
l the plate being straightened must create a rigid kinematic coupling between the straightening rollers, the rollers of the housing, and the adjacent sections of the roller conveyors;
l the plate should undergo elongation during the straightening operation as a result of plastic deformation, with the increments in length being different on each working roller due to the differentiation of the bending radii;this situation leads to a nonuniform increase in the speed of the plate as it moves toward the end of the PSM;
l it must be possible to use working rollers of different diameters (this being done, for example, due to nonuniform wear or regrinding);
l the loads on the rollers should be differentiated in accordance with the chosen straightening re
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