機械專業(yè)畢業(yè)設(shè)計（論文）外文翻譯圓型經(jīng)編機的偽造伺服系統(tǒng)

1、圓型經(jīng)編機的偽造伺服系統(tǒng)摘要經(jīng)編技術(shù)通常都是運用在直絲(線性)經(jīng)編機上的。使用一種新概念的錐形針床并附上凸輪驅(qū)動模式圓環(huán)的圓型經(jīng)編機，最近成為一種可能。這需要一個機械聯(lián)動傳遞的凸輪運動模式,但很容易產(chǎn)生環(huán)振動的不良水平。新一代的設(shè)計中取代機械凸輪和聯(lián)動高速無刷直流伺服電機，使圖案的精確成為無限可能。經(jīng)報道，方法選擇的基于最大程度的減少了伺服電機的功率以及完成最快的運動要求。通過選擇最小合適的指定應用伺服電機驅(qū)動的方法保證了成本最小化。經(jīng)報道,一個圓型經(jīng)編機采用伺服電機以及其驅(qū)動機器使用方法的選定設(shè)計、建造,并測試使用成功。2001科學出版社有限公司。保留所有權(quán)利。簡介:模式機制概述直絲經(jīng)編機使

2、用了三個主要機制產(chǎn)生制針過程。針織機制針即是前邊垂直擺動筒子紗的機制從前線移動到后面的針和一個移針距機制產(chǎn)生重疊，然后和從下面露出的平面針進行平行鋪設(shè)。這臺機器的模式在最大程度上取決于動作的難易修改它的每個移針距形成的機理和字符串的長度鏈。經(jīng)編針周期在針織機上可以被描述成六個階段(見圖1)。從針在他們的最高位置,有以前的循環(huán)圓自己干,在階段(1)從后面紗線擺動到前面的針。在階段(2)下一個線程被鋪設(shè)的鉤子表演,而一針一針從側(cè)身空間到下一個的重疊。然后擺動的紗線的回到了針的平臺(3)。然后就開始移動針向下,舊的環(huán)路的每一針被鎖住的,導致柜子的關(guān)閉。這些針繼續(xù)向下移動,直到老循環(huán)到達山頂?shù)尼?(階

3、段(4),拉動了織物張力。在階段(5),下面織針的線程再一次,這一次后面的針重復。(階段(6),線程在鉤子上打開柜子,成為下一個循環(huán)。在圓型經(jīng)編機上，紗線接頭都是通過非穿孔環(huán)。旋轉(zhuǎn)運動的成為與圖案,這些環(huán)鏈是由多種旋轉(zhuǎn)運動與圓環(huán)在同步的主要機制負責往復式針縱向(見圖2),戒指必須履行的兩種截然不同的輪換和兩個住在機器周期。今后的研究方向和幅值的旋轉(zhuǎn)將取決于織物結(jié)構(gòu)產(chǎn)生的吧。然而,一份重疊總是會進行過超過一針,而一個只可在幾針并且可以因此需要一個更大的輪換的戒指。大的數(shù)目的戒指,可能性更大的模式。然而,一定數(shù)量的空間放置他們和紗線的路徑的復雜度的數(shù)量一般限制環(huán)中存在模式的機器。系統(tǒng)要求第一次設(shè)計

4、原型被用來當作工業(yè)針織機生產(chǎn)包裝面料、長統(tǒng)襪繃帶材料和其他技術(shù)紡織品。產(chǎn)品設(shè)計規(guī)格為機器覆蓋所有這些市場中實施,從而建立起企業(yè)終端產(chǎn)品的要求。研究發(fā)現(xiàn),大多數(shù)應用程序不需要多于一個4倍下去針距。此外,最小規(guī)格(每英寸的針數(shù))在相關(guān)應用四歲。氣缸的直徑是不重要的,這種情況在組網(wǎng)應用的范圍為75100毫米的長統(tǒng)襪,這完全是因人而異的應用和廣泛的應用于醫(yī)學應用。為第一原型,75mm直徑缸使用。這個尺寸缸、四針空間四針每英寸相當于38氣缸。一個4針距將可能需要的旋轉(zhuǎn)8針空間,相當于76。這也正是決定向以及系統(tǒng)的要求,即模式機制必須能完成多達80的旋轉(zhuǎn),在一個單一的下針距。設(shè)計師可以改變織物的編織周期的

5、一部分分配給模式和企業(yè)生態(tài)位重疊動作。在初步設(shè)計圓形的助燃機,三分之一的機器周期被認為是sucient為針的運動。這使得三分之二的針織周期來執(zhí)行120和重疊互相矛盾。假設(shè)的最大速度是1000轉(zhuǎn)數(shù),這臺機器單一針織循環(huán)發(fā)生在60歲的女士。這樣只剩下20 ms履行重疊和20的旋轉(zhuǎn)。機械解決辦法其專利模式機制2、5都是機械控制模式,使用兩個凸輪控制的開放,面對環(huán)模式和有最大長度的12機周期。人數(shù)限制周期是由于空間限制。較大數(shù)量的機器周期模式里需要一個更大的凸輪的空間,但在凸輪的大小是有限的。主要的進步達到與機械方法解決建設(shè)作為本研究之部分:(1)使用封閉模式凸輪凸輪追隨者,減少沖擊和振使用開放,面對

6、凸輪時形成的,(2)改進的生產(chǎn)工藝模式的凸輪通過開發(fā)一個特制的工具建立出銑削程序的模式,(3)凸輪機構(gòu)的凸輪性能提高利用擺線針輪箴les的每一個片段。擺線針輪剖面進行已知能給你最好的結(jié)果為高速應用3相比其他基本位移曲線,因為它們提供了三種有限的衍生品的位移。給出了擺線針輪位移。唯一的缺點,使用這種類型的職業(yè)樂為當前的應用是基于混球曲線的結(jié)束點的各運動。也就是說,在節(jié)點處上升(或收益)期間結(jié)束時期開始和居住。這是因為第三種派生的位移不為零,而在終點的住。如果有必要,運動曲線可能會有進一步的優(yōu)化利用poly-nomial檔案,來確保位移及其三個衍生物是連續(xù)貫穿始終。研制了一種特制的計算機應用程序,

7、創(chuàng)造出一種凸輪廓線,然后再下載到一個數(shù)控銑床。一旦在針織機、凸輪運動中是使用高速lmed錄像機(200幀每秒)。沒有過多的振動;即使追隨者幀觀看時都已經(jīng)看到,跟隨者的沒有離開一側(cè)的軌道上,這是滾動。機械系統(tǒng)的作用是:將創(chuàng)造的直線移動模式的旋轉(zhuǎn)凸輪進一環(huán)通過模式有一定數(shù)量的樞紐和機械連接(見圖2)。組件和長度的聯(lián)系在很大程度上取決于身體的可用空間和尺寸對機器零件的制造和銷售。例如,為了創(chuàng)造出一個長循環(huán)運動的模式由環(huán),同時保持適當?shù)膲毫堑耐馆?、基線半徑等一定增加。雖然凸輪機構(gòu)跑光滑,高速的視頻顯示過度振動模式的戒指。對比的平穩(wěn)運行和不規(guī)則的凸輪機構(gòu)從動件運動圓環(huán)表明,后者是由彈性機械連接。機器的

8、速度會因此總是會受到其力學性能和尺寸的連接。證明了這種機械的設(shè)計概念的圓形經(jīng)編機制是可行的。伺服控制系統(tǒng)一種全新的方法是控制模式的機理問題采用伺服電機的環(huán)。雖然更昂貴的解決方案,它具有潛在地產(chǎn)生模式鏈條,只是大小限制的記憶(i.e.hundreds用五機械周期而不是12個機械周期)和縮短了時間和部分從一個模式需要改變到另一個地方。此外,伺服電機,會產(chǎn)生一種旋轉(zhuǎn)運動,當耦滑輪組可以駕駛模式環(huán)直接。沒有必要機械轉(zhuǎn)型到一個旋轉(zhuǎn)的一個直線移動,則可能是要求如果其他的電子控制線性驅(qū)動的機械設(shè)備,使用,如線性氣動執(zhí)行機構(gòu)。被選擇的伺服電機的步進電機由于反應的速度和位置控制要求給出的針織的申請。本文涉及的伺

9、服控制的模式機制而已。但是,主要機制,即針織負責針運動也可以通過伺服系統(tǒng)給予更多的控制之間的同步針和紗線。6提出一種提高動態(tài)特性,通過控制的凸輪機構(gòu)從動件凸輪的使用伺服電機的速度?；谥本€電機的經(jīng)編機橫移控制系統(tǒng)設(shè)計摘要 本文以三相永磁無刷直流直線電機及驅(qū)動控制系統(tǒng)為主要研究對象，采用數(shù)字信號處理器(dsp)為控制核心對經(jīng)編機橫移機構(gòu)進行實用設(shè)計。文中給出了系統(tǒng)的總體設(shè)計方案，闡述了該系統(tǒng)的基本結(jié)構(gòu)、工作原理、運行特性及其設(shè)計方法。另外，文中還對各硬件模塊(直線電機驅(qū)動電路、位置檢測電路、電流檢測等)電路設(shè)計以及各軟件模塊進行了詳細的分析。關(guān)鍵詞：經(jīng)編機；橫移運動；直線電機；dsp；pwm；p

10、id1 引言經(jīng)編丁業(yè)是紡織工業(yè)的一個重要組成部分，經(jīng)編產(chǎn)業(yè)的快速發(fā)展推動了經(jīng)編機設(shè)備制造技術(shù)的不斷更新。開發(fā)和研制出技術(shù)含量高、生產(chǎn)效率高、可靠性高的高檔智能化經(jīng)編機，核心技術(shù)是需要經(jīng)編機梳櫛橫移精度高，因為高精度的橫移機構(gòu)在回復運動過程中，可以保證織針回擺過相應的導紗針時，一個橫移時間就完成。因此開發(fā)和研制出智能化的高精度經(jīng)編機意義深遠。2 當前的經(jīng)編機橫移機構(gòu)控制系統(tǒng)21機械式經(jīng)編機橫移機構(gòu) 機械式多梳櫛提花經(jīng)編機是由高低尺寸不一的鏈塊縱橫排列成鏈帶，編織花型時該鏈帶循環(huán)走動，按照花型的要求控制著梳櫛的行程以達到編織花型的目的。這種橫移機構(gòu)的缺點是一種花型就要一種凸輪(或花紋鏈條)，凸輪(

11、或花紋鏈條)加工成本高，花型變化品種有限，且代價昂貴。另外，由于人們對花型要求越來越高，梳櫛數(shù)進一步增加，生產(chǎn)和改變花型已經(jīng)變得越來越困難。在多品種、小批量的買方市場下，用鏈條來進行花型生產(chǎn)非常費事、費時，且成本很高。22新型電子橫移機構(gòu)新型的el(electronic guide baf control system)橫移機構(gòu)、su(summe blech)橫移機構(gòu)、鋼絲花梳橫移機構(gòu)、地梳和賈卡梳橫移機構(gòu)均采用伺服電機控制。el適用于連續(xù)的、快速的花型變換。機器速度受到限制。su橫移機構(gòu)借助滑動組件來控制花梳，通過電磁元件來控制滑動組件，從而可按照確定的路徑來形成橫移路徑距離。但是它的極限是

12、最大47針的橫移距離和每分鐘450轉(zhuǎn)的最大轉(zhuǎn)速。新型的鋼絲花梳、地梳和賈卡梳橫移機構(gòu)都采用了伺服電機控制。每個鋼絲花梳連接一個伺服電機，由伺服電機執(zhí)行橫移運動，鋼絲梳通過空氣壓縮機進行回復。另一端的反向平衡裝置(氣動張力調(diào)整器)保證鋼絲梳在整個橫移區(qū)間的張力均勻一致。導紗針按照花型進行運動，一個方向借助壓縮空氣，另一個方向通過機械動力，大小由伺服電機控制(如圖2)。另外，karl mayer公司新近研制出了匹艾州壓電式賈卡裝置。它是由壓電陶瓷及賈卡導紗針組成。壓電式賈卡導紗技術(shù)徹底改變了賈卡裝置，無需通絲、移位針等繁雜部件，使賈卡經(jīng)編機提花部分的機構(gòu)大大簡化，有助提高速度。但是橫移距離較小。3

13、 系統(tǒng)總體結(jié)構(gòu)設(shè)計31系統(tǒng)方案的選取針對上面所闡述的當前幾種經(jīng)編機橫移機構(gòu)，本文采用基于直線電機的橫移控制系統(tǒng)，利用直線電機取代花紋鏈塊直接驅(qū)動導紗梳(如圖3)。由直線電機驅(qū)動的傳動裝置，不需要任何轉(zhuǎn)換裝置而直接產(chǎn)生推力，因此，它可以省去中間轉(zhuǎn)換機構(gòu)，簡化了整個裝置或系統(tǒng)，保證了運行的可靠性，提高了傳遞效率，降低了制造成本。另外，由dsp構(gòu)成的電機控制系統(tǒng)相對于單片機或微機具有更高的精度和速度，而且存儲量大，具有邏輯控制功能和各種中斷處理能力，豐富的數(shù)輸入輸出口、通信口、專用電機控制pwm輸出口，各種硬件集成在同一芯片中，從而簡化硬件設(shè)計，提高軟件編程的靈活性。整個系統(tǒng)結(jié)構(gòu)簡單、體積小、可靠性

14、高，實現(xiàn)真正意義上的機電一體化新型高精度經(jīng)編機橫移機構(gòu)控制系統(tǒng)。32系統(tǒng)總體結(jié)構(gòu)框圖本系統(tǒng)采用直線電機型號為深圳大族精密機電有限公司生產(chǎn)的lmcum20420，其最大行程為300mm，連續(xù)推力可達73n，最大電流18a?？梢院芎玫臐M足經(jīng)編機橫移的要求?？刂破鞑捎貌捎胻i公司生產(chǎn)專用于電機控制的tms320lf2407a。基于dsp的直流直線電機控制系統(tǒng)的系統(tǒng)框圖如圖4所示，dsp負責處理采集到的數(shù)據(jù)和發(fā)送控制命令并通過捕獲單元捕捉電動機動子位置傳感器上的脈沖信號，判斷動子位置，輸出合適的驅(qū)動邏輯電平至星型全橋mosfet電路，再由mosfet功率驅(qū)動電路驅(qū)動電機做直線運動；dsp的捕獲單元根據(jù)

15、捕獲的位置傳感器脈沖信號的寬度，計算出電機的當前轉(zhuǎn)速，與電機的設(shè)定轉(zhuǎn)速比較后，利用pid算法產(chǎn)生合適的脈寬調(diào)制信號(pwm)控制電機的轉(zhuǎn)速跟隨轉(zhuǎn)速的設(shè)定值；驅(qū)動保護電路可完成電機的過載、欠壓、過壓等異常故障保護。4系統(tǒng)硬件電路實現(xiàn)41直線電機驅(qū)動電路驅(qū)動電路設(shè)計采用三相星型全橋電路。全橋逆變電路采用六個irf640搭建，在每個管子的基極和發(fā)射極之間并接一個嵌位電阻。電機前置功率管驅(qū)動電路采用ir2130，ir2130芯片的每6路輸出控制驅(qū)動電路的上半橋和下半橋?qū)P(guān)斷，從而控制控制電機的轉(zhuǎn)速和正反方向橫移，同時起到過載、欠壓、過壓等異常故薛保護。由ir2130和mosfet組成的電機驅(qū)動電路如

16、圖5所示。圖5三相星型全橋式電機驅(qū)動電路圖42位置檢測電路在直線電機的控制系統(tǒng)中，要實現(xiàn)對直線位移的精確控制，就必須通過高精度的檢測裝置對它進行檢測，將檢測結(jié)果轉(zhuǎn)換成數(shù)字量反饋給dsp，由dsp對這些數(shù)據(jù)進行處理。系統(tǒng)使用直線光柵傳感器進行電機位置檢測。光柵位置檢測裝置由光源、兩塊光柵(長光柵、短光柵)和光敏元件等組成。如果將指示光柵在其自身的平面內(nèi)轉(zhuǎn)過一個很小的角度0，這樣兩光柵的刻線相交，則在相交處出現(xiàn)黑色條紋，稱為莫爾條紋。由于兩塊光柵的刻線密度相等，即柵距w相等，而產(chǎn)生的莫爾條紋的方向和光柵刻線方向大致垂直，所以當o很小時，其條紋間b和光柵柵距w及2條光柵刻線夾角關(guān)系為：當光柵相對移動

17、時，莫爾條紋將沿著刻線方向移動。光柵移動一個柵距，莫爾條紋也移動一個間距b，同時；在指示光柵上的光敏元件接收到一次光脈沖的照射，并相應輸出1個電脈沖。通過計數(shù)電脈沖的數(shù)目，就可以測量標尺光柵的位移x，即： x=iw （2）43電流檢測電路采用wbl414電流傳感器作為電流檢測裝置，由于三相繞組采用的是星形連接，中點懸空，也就是說，電流的3個變量不完全獨立，只要知道其中兩個，設(shè)為ia和ib，另一個變量ic就可以算出：因而實現(xiàn)電動機相電流的精確檢測，只需兩路檢測電路，將ia和ib的電流值經(jīng)轉(zhuǎn)換后分別送往dsp的adcino和adcinl。電流檢測原理圖如圖6所示。位置檢測不但用于換向控制，而且還用

18、于產(chǎn)生速度控制量。每個周期內(nèi)有6次換相，電機的動子每走過一塊磁鐵都有一次換相(每塊磁鐵的長度15mm)，這樣測得兩次換相的時間間隔為t，就可以根據(jù)式(31)計算出兩次換相間隔期間的平均角速度。兩次換相的時間間隔t可以通過捕捉中斷發(fā)生時讀出定時器2的值來獲得。圖6 電流檢測電路圖5 dsp控制系統(tǒng)軟件實現(xiàn)主程序的主要功能足完成系統(tǒng)的初始化，如系統(tǒng)ram的映射(存儲空間的分配)、看門狗初始化、中斷初始化、i0引腳功能初始化、事件管理器eva的pwm，adc初始化、事件管理器evb的cap初始化、異步串行口初始化等。初始化完成后，主程序在ram中建立基準正弦函數(shù)表，該正弦釃數(shù)表是對幅值為l正弦函數(shù)正

19、半周期采樣900個點得到的。圖7主程序流程框圖6 結(jié)論本文以tms320lf2407a作為控制器。對紡織機械電子橫移系統(tǒng)的電子凸輪機構(gòu)進行了實用設(shè)計。系統(tǒng)充分利用直線電機的優(yōu)點，采用電流環(huán)、速度環(huán)的雙閉環(huán)控制電極的位置和速度，pid算法對參數(shù)進行反復優(yōu)化，使系統(tǒng)達到預期的位移控制精度和頻率響應，并且在經(jīng)編機電子橫移系統(tǒng)上運行可靠。patterning servo-mechanism for a circular warp knitting machineabstractwarp knitting is always performed on flat (linear) knitting mac

20、hines. a circular warp-knitting machine is recently made possible by using a novel concept of a conical needle bed and patterning cams with enclosed cam followers to drive the patterning rings. this also requires a mechanical linkage to transmit the motion from the patterning cam to the patterning r

21、ings, which is prone to vibration at undesirable levels. a new generation design replaces the mechanical cam and linkage with high-speed ac brushless servomotors enabling limitless precision patterning possibilities. a method of selecting servomotors based on minimising the power required to perform

22、 the fastest motion required for a given application is reported. this method ensures cost minimising by selecting the smallest servomotor suitable for a given application. a circular warp-knitting machine using servomotor to drives selected using the method reported is designed, built and successfu

23、lly tested.2001 elsevier science ltd. all rights reserved.introduction: patterning mechanism overviewflat warp knitting machines employ three main mechanisms to produce stitches.namely, a knitting mechanism that reciprocates the needles vertically, a swingingmechanism to move the yarns from the fron

24、t to the back of the needles and ashogging mechanism to produce the overlaps and underlaps parallel to the plane on which the needles are laid.a pattern consists of a chain of dierent length underlaps and hence theexibilityof the machine patterning depends on the ease of modifying the movements per-

25、formed by its shogging mechanism and the length of the pattern chain.the warp knitting needle cycle for a at knitting machine can be described ascomprising six stages (see fig. 1). starting with the needles at their highest position and having the previous loops round their stem, in stage (1) the ya

26、rns are swung from the back to the front of the needles. at stage (2), the overlap, a thread is laid under the hook of the needle by performing a sideways shog from one needle space to the next. the yarns are then swung to the back of the needle in stage (3). the needles then start to move downwards

27、, the old loops are caught under each needle latch and cause the latches to close. the needles continue moving down until the old loops reach the top of the needle, are cast-o (stage (4) and pulled by fabric tension. at stage (5), theunderlap, the threads are shogged again, this time behind the need

28、les.as the needles rise again (stage (6), the threads in the hooks open the latches and become the next loops.on a circular machine, the yarns are threaded through radially perforated rings.the shogging movement becomes a rotation of these rings and a pattern chain comprises a number of rotational m

29、ovements of the rings in synchronisation with the main mechanism responsible for reciprocating the needles vertically (see fig. 2).the rings must perform two distinct rotations and two dwells during a machine cycle. the direction and amplitude of the rotations will depend upon the fabric structure b

30、eing created. however, an overlap will always be carried out over one needle only, while an underlap can be under several needles and could therefore require a larger rotation of the ring.the larger the number of rings, the greater the patterning possibilities. however,the amount of space to place t

31、hem and the complexity of the yarn paths generally restricts the number of patterning rings present in a machine.system requirementsthe first design prototype was used as an industrial knitting machine to produce packaging fabrics, stockings bandage materials and other technical textiles. a product

32、design specification for a machine to cover all these markets was carried out in order to establish the end products requirements. it was found that most applications would not require more than a 4-needle underlap. in addition, the minimum gauge (number of needles per inch) in the relevant applicat

33、ions was 4. the cylinder diameter is not critical for the netting applications; this varies in the range of 75100mm for the stockings application and it varies widely for medical applications. for the first prototype, a 75-mm diameter cylinder was used. for this size cylinder, four needle spaces at

34、four needles per inch are equivalent to 38 of the cylinder. a 4-needle underlap will probably require a rotation of 8 needle spaces, which is equivalent to 76.it was therefore decided to set as system requirement that the patterning mechanism must be able to perform a rotation of up to 80 in a singl

35、e underlap.the fabric designer can alter the portion of the knitting cycle allocated to the patterning ring movements (underlap and overlap). in the initial design of the circular warp-knitting machine, one-third of the machine cycle was deemed to be sucient for the needles movement. this leaves two

36、 thirds of the knitting cycle to perform the underlap and overlap; 120 each.assuming that the maximum speed of the machine is 1000 rpm, a single knitting cycle takes place in 60 ms. this leaves only 20 ms to perform the underlap and 20 ms for the overlap rotation.mechanical solutionthe patented patt

37、erning mechanisms 2,5 are all mechanically controlled, use two patterning rings controlled by open face cams and have a maximum pattern length of 12 machine cycles. the restriction on the number of cycles is due to space limitation.a larger number of machine cycles in a pattern would require a large

38、r cam, but the space in which the cam ts in is limited.the main progress achieved with the mechanical solution built as part of this research was: (1) the use of enclosed cam followers in the patterning cams, reducing shock and vibration eects created when using open face cams, (2) improvements of t

39、he manufacturing process of the patterning cams by developing a tailor-made tool to create the milling programs of the patterning cam, and (3) enhancement of the cam performance by using cycloidal proles for each segment. cycloidal profiles are known to give the best results for high-speed applicati

40、ons 3when compared to other basic displacement curves, because they provide three finite derivatives of displacement. the cycloidal displacement is given by:the only drawback to using this type of prole for the current application is the non-continuous jerk curve at the end points of each motion. th

41、at is, at the point where the rise (or return) period ends and the dwell period begins. this is because the third derivative of the displacement is not zero at the end point, whereas that of a dwell is. if necessary, the motion curves could be further optimised by using poly-nomial profiles to ensur

42、e that the displacement and its three derivatives are continuous throughout.a tailor-made computer application was developed to create the cam profile program, which is then downloaded into a nc milling machine. once on the knitting machine, the cam in motion was lmed using a high-speed video record

43、er (200 frames per second). there was no excessive vibration of the follower in the cam-track; even when viewed frame by frame it was seen that the follower did not leave the side of the track on which it was rolling.the mechanical system converts a translational motion created by the patterning cam

44、 into a rotation of the patterning ring by means of a number of pivots and mechanical linkages (see fig. 2). the conguration and length of the linkage components depend on the physical space available and the dimensions of the machine elements. for example, in order to create a longer pattern by cir

45、cular motion of the ring, while maintaining appropriate pressure angles in the cam, the baseline radius of the cam must increase.although the cam-follower mechanism ran smoothly, the high-speed video showed excessive vibration of the patterning rings. the contrast between the smooth running of the c

46、am follower and irregular motion of the rings suggests that the latter is created by the elasticity of the mechanical linkages. the speed of the machine would therefore always be constrained by the mechanical properties and the dimensions of the linkages.this mechanical design proved the circular wa

47、rp knitting mechanism concept to be feasible (see fig. 3). however, a design that allowed for more patterning exibility and ultimately higher operational speed was required in order to manufacture the more complex fabric designs used in the medical and stockings industries.servo-controlledsolutionan

48、 entirely new approach to the patterning mechanism problem was to control the rings using servomotors. although a more costly solution, it has the potential of creating pattern chains that are only restricted by the size of the memory of the hardware used (i.e.hundreds of machines cycles rather than

49、 12) and reducing the time and parts required to change from one pattern to another.in addition, a servomotor would produce a rotational motion, when coupled viatiming belts and pulleys could drive the patterning rings directly. there is no need for the mechanical transformation of translational mot

50、ion to a rotational one that would have been required if other electronically controlled linearly actuated mechanical devices were used, such as linear pneumatic actuators.servomotors were selected over stepper motors because of the speed of reaction and position control requirements given by the kn

51、itting application.this paper relates to the servo control of the patterning mechanism only. however, the main knitting mechanism, that is, the one responsible for the needle motion could also be servo-controlled giving further control over the synchronisation between needles and yarns. yao et al. 6

52、 propose a method to improve the motion characteristics of a cam follower by controlling the cam speed using servodrives.the design for warp knitting machine traversing control system based on dspabstract on the basis of studying warp knitting machine traversing control system in-depth,this paper de

53、signed a warp knitting machine traversing electronic control system based on digital signal processor (dsp). this system take a three-phase permanent magnet blushless linear dc motor (lpmbdcm) as main studying object and use dsp as the control center. thereby, it designed a practical electronic guid

54、e bar shogging mechanism. the emphases of this paper are explaining the hardware circuit and the system software, including linear motor driver, position detection, and speed current closed-loop detection and so on.keywords: warp knitting machine; traversing motion;linear motor; dsp; pwm; 1. introdu

55、ctionthe warp knitting industry is an important component of the textile industry, which is promoting the technology of manufacturing equipment of the warp knitting machine renovate. developing and researching a top grade intelligent warp knitting machine of high technology, high productivity, and h

56、igh reliability, the core technology needs a high precision shogging system of guide bar. because the shogging system of high precision could guarantee that guide needle can finish traversing during a shogging motion. accordingly, developing and studying an intelligent warp knitting machine of high

57、precision has extremely important practical significance.2 the existing control system of shogging motion of warp knitting machines2.1 the mechanical warp knitting machine shogging systemnowadays, the most using warp knitting machine is mechanical warp knitting machine in home. it made by different

58、dimension chain block arranged in vertical and horizontal chain belt, which control the patternitinerary to meet chlamys weaving pattern purposes when linked with the walking cycle. however, this machines disadvantage is every kind of pattern needing corresponding cam (or chain belt), which is high-cost. otherwise, producing and changing the patterns have become more and more difficult as the people requires patterns more and more high, and the number of