步進(jìn)電機(jī)應(yīng)用和控制外文翻譯

1、<p>　　畢業(yè)設(shè)計(jì)(論文)外文資料翻譯</p><p>　　題 目: 步進(jìn)電機(jī)應(yīng)用和控制 </p><p>　　院系名稱(chēng)： 信息學(xué)院 專(zhuān)業(yè)班級(jí)： 電科0802班 </p><p>　　學(xué)生姓名： xxx 學(xué) 號(hào)： xxxxxxxxxxxxxxx </p><p>　　指

2、導(dǎo)教師： xxx 教師職稱(chēng)： xxxxxxxxxxxx </p><p>　　地 點(diǎn): xxxxxxxxxxxxx </p><p>　　附 件： 1.外文資料翻譯譯文；2.外文原文。 </p><p>　　附件1：外文資料翻譯譯文</p><p><b&

3、gt;　　步進(jìn)電機(jī)應(yīng)用和控制</b></p><p>　　步進(jìn)電機(jī)是將電脈沖轉(zhuǎn)換成角位移的執(zhí)行機(jī)構(gòu)。通俗的講：當(dāng)步進(jìn)電機(jī)驅(qū)動(dòng)器接收到脈沖信號(hào)，它就驅(qū)動(dòng)步進(jìn)電機(jī)按設(shè)定的方向轉(zhuǎn)動(dòng)一個(gè)固定的角即步進(jìn)角。你可以控制脈沖的個(gè)數(shù)來(lái)控制角位移量，從而能準(zhǔn)確定位；同時(shí)你可以通過(guò)控制脈沖頻率來(lái)控制電機(jī)轉(zhuǎn)動(dòng)的速度和加速度，從而達(dá)到改變速度的目的。 </p><p>　　步進(jìn)電機(jī)不能直接用交直

4、流電源供電，而必須使用專(zhuān)用設(shè)備即步進(jìn)電機(jī)驅(qū)動(dòng)器。步進(jìn)電機(jī)驅(qū)動(dòng)系統(tǒng)的性能，除與電機(jī)自身性能有關(guān)外，在很大程度上取決于驅(qū)動(dòng)器上的好壞。一個(gè)典型的步進(jìn)電機(jī)驅(qū)動(dòng)系統(tǒng)是由步進(jìn)電機(jī)控制器，步進(jìn)電機(jī)驅(qū)動(dòng)器和步進(jìn)電機(jī)三部分組成。步進(jìn)電機(jī)控制器發(fā)出步進(jìn)脈沖和方向信號(hào)，每一個(gè)脈沖，步進(jìn)電機(jī)驅(qū)動(dòng)器驅(qū)動(dòng)步進(jìn)電機(jī)轉(zhuǎn)子旋轉(zhuǎn)一個(gè)步距角，就是一步。步進(jìn)電機(jī)轉(zhuǎn)速的高低，加速和減速，啟動(dòng)或停止完全取決脈沖的有無(wú)和頻率的高低?？刂破鞯姆较蛐盘?hào)決定步進(jìn)電機(jī)的正轉(zhuǎn)或者反轉(zhuǎn)。通常

5、，步進(jìn)電機(jī)驅(qū)動(dòng)器由邏輯控制電路、保護(hù)電路、功率驅(qū)動(dòng)電路和電源組成。當(dāng)步進(jìn)電機(jī)驅(qū)動(dòng)器接收到來(lái)自控制器的方向信號(hào)和步進(jìn)脈沖，控制電路就按照預(yù)先設(shè)定的電機(jī)通電方式產(chǎn)生步進(jìn)電機(jī)各相勵(lì)磁繞組導(dǎo)通或截止信號(hào)。由于控制電路輸出的信號(hào)功率很低，不能提供步進(jìn)電機(jī)所需的輸出功率，所以必須進(jìn)行功率放大，這就是步進(jìn)電機(jī)驅(qū)動(dòng)器的功率驅(qū)動(dòng)部分。功率驅(qū)動(dòng)電路向步進(jìn)電機(jī)控制繞組輸入電流，使其勵(lì)磁形成空間旋轉(zhuǎn)磁場(chǎng)，驅(qū)動(dòng)轉(zhuǎn)子運(yùn)動(dòng)。保護(hù)電路在出現(xiàn)短路、過(guò)載、等故障時(shí)迅速停止

6、驅(qū)動(dòng)器和電機(jī)的運(yùn)行。 </p><p>　　電機(jī)轉(zhuǎn)子通常是永磁轉(zhuǎn)子，通過(guò)定子繞組的電流流時(shí)，定子繞組產(chǎn)生的磁場(chǎng)矢量。磁場(chǎng)會(huì)導(dǎo)致轉(zhuǎn)子的旋轉(zhuǎn)角度，使一對(duì)轉(zhuǎn)子和定子的磁場(chǎng)方向的磁場(chǎng)方向。當(dāng)定子旋轉(zhuǎn)磁場(chǎng)矢量，從不同的角度。另外，作為一種觀(guān)點(diǎn)的轉(zhuǎn)子磁場(chǎng)。為每個(gè)輸入的電脈沖，電機(jī)的旋轉(zhuǎn)角度一步。它的輸出和輸入的角位移是成正比的脈沖，與速度成正比的脈沖頻率。權(quán)力改變繞組的順序，電氣將得到扭轉(zhuǎn)。因此，我們可以控制每個(gè)階段的

7、脈沖數(shù)，頻率和電源繞組來(lái)控制步進(jìn)電機(jī)旋轉(zhuǎn)的順序。</p><p><b>　　步進(jìn)電機(jī)類(lèi)型： </b></p><p>　　永磁式（PM）。磁性一般兩相步進(jìn)電機(jī)，轉(zhuǎn)矩和體積較小，一般步進(jìn)角度為7.5度或15度，多用于空調(diào)上。 </p><p>　　反應(yīng)式（VR），國(guó)內(nèi)一般稱(chēng)為BF，常見(jiàn)的是三相反應(yīng)式，步進(jìn)角度為1.5度，也有五相反應(yīng)式。

8、</p><p>　　混合式（HB），普通的兩相混合式，五相混合式，三相混合，四相混合式，兩相和四相可以通用驅(qū)動(dòng)器。五相和三相只能用自己的驅(qū)動(dòng)器。兩相，四相混合式步進(jìn)角為1.8度，具有小體積，大力距，低噪。</p><p>　　五相混合式步進(jìn)電機(jī)一般為0.72，電機(jī)步距角小，分辨率高，但驅(qū)動(dòng)電路接線(xiàn)復(fù)雜。</p><p>　　三相混合式步進(jìn)電機(jī)步距角為1.2度，但根

9、據(jù)使用1.8度，三相混合式步進(jìn)電機(jī)有兩相混合比五相混合式多極將有助于電動(dòng)夾對(duì)稱(chēng)角，可以比兩相，五相精度高，誤差更小，運(yùn)行更平穩(wěn)。步進(jìn)電機(jī)保持扭矩：步進(jìn)電機(jī)功率是指沒(méi)有旋轉(zhuǎn)，定子鎖住轉(zhuǎn)子的力矩。它是步進(jìn)電機(jī)，通常在低速步進(jìn)電機(jī)的力矩接近保持轉(zhuǎn)矩的時(shí)間，最重要的參數(shù)之一。由于步進(jìn)電機(jī)的輸出轉(zhuǎn)矩與不斷衰減的速度增加，輸出功率也增加了變化的速度，從而保持對(duì)步進(jìn)電機(jī)的扭矩來(lái)衡量，最重要的一個(gè)參數(shù)。例如，當(dāng)人們說(shuō)步進(jìn)電機(jī)2N.m的，在特殊情況下，這

10、意味著保持的步進(jìn)電機(jī)2N.m.的扭矩 精密步進(jìn)電機(jī)：步進(jìn)電機(jī)步距角精度為3-5％，不累計(jì)。 </p><p>　　空載啟動(dòng)頻率：步進(jìn)電機(jī)在無(wú)負(fù)載的正常啟動(dòng)的脈沖頻率的情況下，如果脈沖頻率高于電機(jī)的價(jià)值沒(méi)有啟動(dòng)，可能丟步或堵。在負(fù)載的情況下，啟動(dòng)頻率應(yīng)更低。如果你想實(shí)現(xiàn)高速旋轉(zhuǎn)的電機(jī)，脈沖頻率應(yīng)該加快進(jìn)程，也就是說(shuō)，在較低的頻率開(kāi)始，然后上升到所需的頻率一定的加速度（電機(jī)轉(zhuǎn)速?gòu)牡偷礁撸?</

11、p><p>　　步距角：即發(fā)送一個(gè)脈沖，相應(yīng)的電角度旋轉(zhuǎn)。 </p><p>　　扭矩定位：定位力矩步進(jìn)電機(jī)沒(méi)有電的情況下，鎖住轉(zhuǎn)子的力矩定子。 </p><p>　　工作頻率：步進(jìn)電機(jī)一步步運(yùn)行的最高頻率。細(xì)分驅(qū)動(dòng)器： 步進(jìn)電機(jī)細(xì)分驅(qū)動(dòng)器的主要目的是減弱或消除步進(jìn)電機(jī)的低頻振動(dòng)，提高電機(jī)的運(yùn)轉(zhuǎn)精度。減少噪音。如對(duì)于步距角為1.8°（整步）兩相混合

12、式步進(jìn)電機(jī)，如果細(xì)分驅(qū)動(dòng)器的細(xì)分?jǐn)?shù)為8，那么電機(jī)的運(yùn)轉(zhuǎn)分辨率為每個(gè)脈沖0.072°，電機(jī)的精度能否達(dá)到或接近0.225°，還取決于細(xì)分驅(qū)動(dòng)器的細(xì)分電流控制精度等其他因素，細(xì)分?jǐn)?shù)越大精度越難控制。</p><p>　　步進(jìn)電機(jī)有以下好處：（1）成本低廉（2）堅(jiān)固耐用（3）結(jié)構(gòu)簡(jiǎn)單（4）高可靠性（5）無(wú)維修（6） 適用廣泛（7）穩(wěn)定性很高（8）無(wú)需反饋元件（8）適應(yīng)多種工作環(huán)境因此，幾乎沒(méi)有任何可

13、以想象的失敗使步進(jìn)驅(qū)動(dòng)模塊出錯(cuò)。 </p><p>　　步進(jìn)電機(jī)驅(qū)動(dòng)簡(jiǎn)單，并且驅(qū)動(dòng)和控制在一個(gè)開(kāi)放的閉環(huán)系統(tǒng)內(nèi)。他們只需要4個(gè)驅(qū)動(dòng)器。低速時(shí)，驅(qū)動(dòng)器提供良好的扭矩，是有刷電機(jī)同一幀大小5 倍連續(xù)力距，或相當(dāng)于無(wú)刷電機(jī)一倍扭矩。這往往不再需要變速箱。步進(jìn)驅(qū)動(dòng)系統(tǒng)遲緩，在限定的范圍內(nèi)，可以更好的 減少動(dòng)態(tài)位置誤差。 </p><p>　　步進(jìn)電機(jī)有下列缺點(diǎn)：（1）共振效應(yīng)和相對(duì)長(zhǎng)的適應(yīng)性。（2

14、）在低速表現(xiàn)粗糙，除非微驅(qū)動(dòng)器來(lái)驅(qū)動(dòng)。（3）開(kāi)環(huán)系統(tǒng)可能導(dǎo)致未被查覺(jué)的損失。（4）由于過(guò)載，他們消耗過(guò)多電流。因此傾向于過(guò)熱運(yùn)行。（5）虧損速度比較高，并可產(chǎn)生過(guò)多熱量因此，他們?cè)胍艉艽螅ㄓ绕涫窃诟咚傧拢?。?）他們的滯后現(xiàn)象導(dǎo)致振蕩，這是很難抑制的。對(duì)他們的可行性，這兒有一個(gè)限度，而他們的大小，定位精度主要依靠的是機(jī)器（例如，滾珠絲杠的精確度）。這些缺點(diǎn)是可以克服的，通過(guò)使用一個(gè)閉環(huán)控制方案。 </p><p>

15、;　　當(dāng)電動(dòng)機(jī)驅(qū)動(dòng)，在其全步模式，給兩個(gè)繞組通電時(shí)即"2 相"通電的時(shí)候（見(jiàn)圖 1.8 ），每一步的扭矩是相同的（除極少數(shù)的變異和傳動(dòng)特性）,在半步模式下，我們交替改變兩相電流，如圖 1.9 所示。假設(shè)該驅(qū)動(dòng)器在每種情況下提供了相同的繞組電流，再通電時(shí)，這將導(dǎo)致更大的轉(zhuǎn)矩。換句話(huà)說(shuō)，交替的步進(jìn)距將時(shí)強(qiáng)時(shí)弱。對(duì)電動(dòng)機(jī)表現(xiàn)來(lái)說(shuō)，這并不代表著一個(gè)重大的危險(xiǎn)。扭矩明顯受制于較弱的一步，但在全步模式時(shí)，低速平滑有一個(gè)顯著的改善

16、。顯然，我們想在每一個(gè)步驟實(shí)現(xiàn)約相等扭矩對(duì)時(shí)，這扭矩應(yīng)該在水平較強(qiáng)的一步。當(dāng)只有一個(gè)繞組通電時(shí)，通過(guò)用高電平來(lái)實(shí)現(xiàn)。這并不過(guò)度消耗電機(jī)，因?yàn)樵撾姍C(jī)的額定電流假定兩個(gè)階段被激活（目前的評(píng)級(jí)是基于許可的溫度）。只有一相通電，如果目前是增加了40 ％的功率，同樣的總功率將會(huì)消散。利用這種更高的電流在一相中產(chǎn)生大致相等的扭矩，在交替的步進(jìn)距中。（見(jiàn)圖1.10 ）。</p><p>　　我們已經(jīng)看到，給兩相都通與平等電流產(chǎn)

17、生的一個(gè)中間步進(jìn)，居于每一相的中間位置。如果兩相電流是不平等的， 轉(zhuǎn)子位置將轉(zhuǎn)向更強(qiáng)的一極。這種作用是利用細(xì)分驅(qū)動(dòng)，其中細(xì)分的大小基于兩個(gè)繞組中的電流的大小。以這種方式，步長(zhǎng)是減少了，而低速平滑度得到大幅度提高。高細(xì)分驅(qū)動(dòng)電動(dòng)機(jī)細(xì)分整步步進(jìn)到多達(dá)500 個(gè)細(xì)分步，轉(zhuǎn)一圈可細(xì)分十萬(wàn)步。在這種情況下，繞組中的電流極為相似的兩個(gè)正弦波有90°相移。圖1.11 電機(jī)被驅(qū)動(dòng)好像轉(zhuǎn)換成了交流同步電機(jī)。事實(shí)上，步進(jìn)電機(jī)可被驅(qū) 動(dòng)，從60赫茲

18、美（50赫茲-歐洲）正弦波源頭起，包括電容器系列的一相。它將旋轉(zhuǎn) 72轉(zhuǎn)。 </p><p>　　圖 1.11 步進(jìn)電機(jī)的相電流 </p><p>　　標(biāo)準(zhǔn)步進(jìn)電機(jī)運(yùn)行在同就如同我們的簡(jiǎn)單模式，但有一個(gè)更大的數(shù)目齒數(shù)在轉(zhuǎn) 子和定子中，從而有了一個(gè)較小的基本步長(zhǎng)。轉(zhuǎn)子有2部分，但每部分有50個(gè)齒。 該半齒位于兩部分之間。定子每5個(gè)齒有 8個(gè)極，完整的共有40個(gè)齒（見(jiàn)圖1.12 ） </

19、p><p>　　圖 1.12 200步混合標(biāo)準(zhǔn)電機(jī)</p><p>　　如果我們想象一個(gè)齒，是擺在2個(gè)定子極點(diǎn)每一齒隙中， 假設(shè)定子共有48個(gè)齒， 少于轉(zhuǎn)子齒數(shù)兩個(gè)。因此，如果轉(zhuǎn)子和定子的齒排列一整圈，他們同樣也可以排列 半圈。1/4和3/4圈也同樣可以排列。 然而，由于轉(zhuǎn)子齒排列位置，在另一端的轉(zhuǎn) 子，排列將發(fā)生在1/4和3/4位置處。 繞組4個(gè)一組，并對(duì)角線(xiàn)方向的極性相反。如圖1.12所

20、示 ，北極在轉(zhuǎn)子前面 的12點(diǎn)和 6點(diǎn)位置，吸引著在在背面 3時(shí)和 9 時(shí)的南極。通過(guò)開(kāi)關(guān)第二組線(xiàn)圈的電 流，定子場(chǎng)模式旋轉(zhuǎn)45 °。不過(guò)，要配合這個(gè)新的領(lǐng)域，轉(zhuǎn)子只轉(zhuǎn)過(guò)1.8 °。相當(dāng) 于轉(zhuǎn)子，這只轉(zhuǎn)過(guò)了四分之一齒間距，每一次旋轉(zhuǎn)要200個(gè)全步。注意到，每一次旋轉(zhuǎn)全部時(shí)這兒有很多定位點(diǎn)位置，通常是200個(gè) 。該定位點(diǎn) 的位置與轉(zhuǎn)子齒全面接軌定子齒時(shí)相對(duì)應(yīng)。當(dāng)通電給步進(jìn)驅(qū)動(dòng)器時(shí)， 它通常是"零 階段&quo

21、t;狀態(tài)時(shí)最活躍，也就是兩套繞組都通電。因此產(chǎn)生的轉(zhuǎn)子位置并不符合轉(zhuǎn)子自 然定位點(diǎn)的位置。因此，空載時(shí)，一旦通電電機(jī)將至少步進(jìn)半步。當(dāng)然，如果系統(tǒng)關(guān)機(jī)，或在零相位位置，電機(jī)一旦通電將步進(jìn)一大步。 </p><p>　　另一點(diǎn)要注意的是，對(duì)于一個(gè)給定電流的繞組，有很多穩(wěn)定的位置，正如轉(zhuǎn)子 齒（200步進(jìn)電機(jī)有50個(gè)齒）。如果電機(jī)是同步電機(jī)，導(dǎo)致位置誤差將永遠(yuǎn)是一個(gè) 整體倍轉(zhuǎn)子齒或能被7.2 °整除 。電機(jī)

22、不能"細(xì)分"，如個(gè)別一個(gè)或兩個(gè)位置誤差，是 由于噪聲，錯(cuò)誤脈沖或控制器故障造成的。</p><p>　　步進(jìn)電機(jī)驅(qū)動(dòng)方法：步進(jìn)電動(dòng)機(jī)不能直接接到工頻交流或直流電源上工作，而必須使用專(zhuān)用的步進(jìn)電動(dòng)機(jī)驅(qū)動(dòng)器，它由脈沖發(fā)生控制單元、功率驅(qū)動(dòng)單元、保護(hù)單元等組成。圖中點(diǎn)劃線(xiàn)所包圍的二個(gè)單元可以用微機(jī)控制來(lái)實(shí)現(xiàn)。驅(qū)動(dòng)單元與步進(jìn)電動(dòng)機(jī)直接耦合，也可理解成步進(jìn)電動(dòng)機(jī)微機(jī)控制器的功率接口，這里予以簡(jiǎn)單介紹。

23、</p><p>　　最新技術(shù)發(fā)展：國(guó)內(nèi)外對(duì)細(xì)分驅(qū)動(dòng)技術(shù)的研究十分活躍，高性能的細(xì)分驅(qū)動(dòng)電路，可以細(xì)分到上千甚至任意細(xì)分。目前已經(jīng)能夠做到通過(guò)復(fù)雜的計(jì)算使細(xì)分后的步距角均勻一致，大大提高了步進(jìn)電機(jī)的脈沖分辨率，減小或消除了震蕩、噪聲和轉(zhuǎn)矩波動(dòng)，使步進(jìn)電機(jī)更具有“類(lèi)伺服”特性。 </p><p>　　對(duì)實(shí)際步距角的作用：在沒(méi)有細(xì)分驅(qū)動(dòng)器時(shí)，用戶(hù)主要靠選擇不同相數(shù)的步進(jìn)電機(jī)來(lái)滿(mǎn)足自己對(duì)步距角的

24、要求。如果使用細(xì)分驅(qū)動(dòng)器，則用戶(hù)只需在驅(qū)動(dòng)器上改變細(xì)分?jǐn)?shù)，就可以大幅度改變實(shí)際步距角，步進(jìn)電機(jī)的‘相數(shù)’對(duì)改變實(shí)際步距角的作用幾乎可以忽略不計(jì)。</p><p><b>　　附件2：外文原文</b></p><p>　　References: Stepping motor application and control[J]. Mechanical and Elect

25、ricalEngineering Technology, 2004，33（1）：69-70</p><p>　　Stepping motor application and control</p><p>　　stepper motor is an electrical pulse will be converted into angular displacement of the imp

26、lementing agencies. Put it in simple language-speaking: When the stepper drive pulse signal to a receiver, it drives stepper motor rotation direction by setting a fixed point of view (and the step angle). You can control

27、 the number of pulses to control the amount of angular displacement, so as to achieve the purpose of accurate positioning; At the same time, you can by controlling the pulse frequency to co</p><p>　　Stepper

28、motor directly from the AC-DC power supply, and must use special equipment - stepper motor drive. Stepper motor drive system performance, in addition to their own performance with the motor on the outside, but also to a

29、large extent depend on the drive is good or bad. A typical stepper motor drive system is operated by the stepper motor controller, stepper motor drives and stepper motor body is composed of three parts. Stepper motor con

30、troller stepper pulse and direction signal, each mad</p><p>　　Motor is usually for the permanent magnet rotor, when the current flows through the stator windings, the stator windings produce a magnetic field

31、 vector. The magnetic field will lead to a rotor angle of rotation, making a pair of rotor and stator magnetic field direction of the magnetic field direction. When the stator rotating magnetic field vector from a differ

32、ent angle. Also as the rotor magnetic field to a point of view. An electrical pulse for each input, the motor rotation angle step. Its </p><p>　　Stepper motor types: </p><p>　　Permanent magnet (

33、PM). Magnetic generally two-phase stepper, torque and are smaller and generally stepping angle of 7.5 degrees or 15 degrees; put more wind for air-conditioning. </p><p>　　Reactive (VR), the domestic general

34、called BF, have a common three-phase reaction, step angle of 1.5 degrees; also have five-phase reaction. Noise, no torque has been set at a large number of out. </p><p>　　Hybrid (HB), common two-phase hybri

35、d, five-phase hybrid, three-phase hybrid, four-phase hybrid, two-phase can be common with the four-phase drive, five-phase three-phase must be used with their drives; </p><p>　　Two-phase, four-phase hybrid s

36、tep angle is 1.8 degrees more than a small size, great distance, and low noise; </p><p>　　Five-phase hybrid stepping motor is generally 0.72, the motor step angle small, high resolution, but the complexity o

37、f drive circuits, wiring problems, such as the 5-phase system of 10 lines. </p><p>　　Three-phase hybrid stepping motor step angle of 1.2 degrees, but according to the use of 1.8 degrees, the three-phase hybr

38、id stepping motor has a two-phase mixed than the five-phase hybrid more pole will help electric folder symmetric angle, it can be more than two-phase, five-phase high accuracy, the error even smaller, run more smoothly.

39、</p><p>　　Stepper motor to maintain torque: stepper motor power means no rotation, the stator locked rotor torque. It is a stepper motor, one of the most important parameters, usually in the low-speed steppe

40、r motor torque at the time of close to maintain the torque. As the stepper motor output torque increases with the speed of constant attenuation, the output power also increases with the speed of change, so as to maintain

41、 torque on the stepper motor to measure the parameters of one of the most important</p><p>　　Precision stepper motors: stepper motor step angle accuracy of 3-5%, not cumulative. </p><p>　　Start

42、frequency of no-load: the stepper motor in case of no-load to the normal start of the pulse frequency, if the pulse frequency is higher than the value of motor does not start, possible to lose steps or blocking. In the c

43、ase of the load, start frequency should be lower. If you want to achieve high-speed rotation motor, pulse frequency should be to accelerate the process, that is, the lower frequency to start, and then rose to a certain

44、acceleration of the desired frequency (motor speed fro</p><p>　　Step angle: that is to send a pulse, the electrical angle corresponding to rotation. </p><p>　　Torque positioning: positioning tor

45、que stepper motor does not refer to the case of electricity, locked rotor torque stator. </p><p>　　Operating frequency: step-by-step stepper motor can run without losing the highest frequency. </p>&l

46、t;p>　　Subdivision Drive: stepper motor drives the main aim is to weaken or eliminate low-frequency vibration of the stepper motor to improve the accuracy of the motor running. Reduce noise. If the step angle is 1.8 &#

47、176; (full step) the two-phase hybrid stepping motor, if the breakdown of the breakdown of the number of drives for the 8, then the operation of the electrical pulse for each resolution of 0.072 °, the precision of

48、motor can reach or close to 0.225 °, also depends on the breakdown of the break</p><p>　　Stepper motors have the following benefits: </p><p>　　? Low cost </p><p>　　? Ruggedness

49、 </p><p>　　? Simplicity in construction </p><p>　　? High reliability </p><p>　　? No maintenance </p><p>　　? Wide acceptance </p><p>　　? No tweaking to stab

50、ilize </p><p>　　? No feedback components are needed </p><p>　　? They work in just about any environment Inherently more failsafe than servo motors. There isvirtually no conceivable failure withi

51、n the stepper drive module that could cause the motor to run away. Stepper motors are simple to drive and control in an open-loop configuration. They only require four leads. They provide excellent torque at low speeds,

52、up to 5 times the continuous torque of a brush motor of the same frame size or double the torque of the equivalent brushless motor. This often elimi</p><p>　　Stepper motors have the following disadvantages:

53、? Resonance effects and relatively long settling times ? Rough performance at low speed unless a microstep drive is used ? Liability to undetected position loss as a result of operating open-loop ? They consume current r

54、egardless of load conditions and therefore tend to run hot ? Losses at speed are relatively high and can cause excessive heating, and they are frequently noisy (especially at high speeds). ? They can exhibit lag-lead osc

55、illation, w</p><p>　　When the motor is driven in its full-step mode, energizing two windings or “phases” at atime (see Fig. 1.8), the torque available on each step will be the same (subject to very small var

56、iations in the motor and drive characteristics). In the half-step mode, we are alternately energizing two phases and then only one as shown in Fig. 1.9. Assuming the drive delivers the same winding current in eachcase, t

57、his will cause greater torque to be produced when there are two windings energized. In other w</p><p>　　torque should be at the level of the stronger step. We can achieve this by using a higher current level

58、 when there is only one winding energized. This does not over dissipate the motor because the manufacturer’s current rating assumes two phases to be energized the current rating is based on the allowable case temperature

59、). With only one phase energized, the same total power will be dissipated if the current is increased by 40%. Using this higher current in the one-phase-on state produces approx</p><p>　　Fig. 1.8 Full step c

60、urrent, 2-phase on</p><p>　　Fig. 1.9 Half step currentFig. 1.10 Half step current, profiled</p><p>　　We have seen that energizing both phases with equal currents produces an intermediate step po

61、sition half-way between the one-phase-on positions. If the two phase currents are unequal, the rotor position will be shifted towards the stronger pole. This effect is utilized in the microstepping drive, which subdivide

62、s the basic motor step by proportioning the </p><p>　　current in the two windings. In this way, the step size is reduced and the low-speed smoothness is dramatically improved. High-resolution microstep drive

63、s divide the full motor step into as many as 500 microsteps, giving 100,000 steps per revolution. In this situation, the current pattern in the windings closely resembles two sine waves with a 90° </p><p&

64、gt;　　phase shift between them (see Fig. 1.11). The motor is now being driven very much as though it is a conventional AC synchronous motor. In fact, the stepper motor can be driven in this way from a 60 Hz-US (50Hz-Europ

65、e) sine wave source by including a capacitor in series with one phase. It will rotate at 72 rpm.</p><p>　　Fig. 1.11 Phase currents in microstep mode</p><p>　　Standard 200-Step Hybrid Motor The s

66、tandard stepper motor operates in the same way as our simple model, but has a greater number of teeth on the rotor and stator, giving a smaller basic step size. The rotor is in two sections as before, but has 50 teeth on

67、 each section. The half-tooth displacement between the two sections is retained. The stator has 8 poles each with 5 teeth, making a total of 40 teeth (see Fig. 1.12). </p><p>　　Fig. 1.12 200-step hybrid moto

68、r</p><p>　　If we imagine that a tooth is placed in each of the gaps between the stator poles, there would be a total of 48 teeth, two less than the number of rotor teeth. So if rotor and stator teeth are ali

69、gned at 12 o’clock, they will also be aligned at 6 o’clock. At 3 o’clock and 9 o’clock the teeth will be misaligned. However, due to the displacement between the sets of rotor teeth, alignment will occur at 3 o’clock and

70、 9 o’clock at the other end of the rotor. The windings are arranged in sets of four,</p><p>　　Another point to remember is that for a given current pattern in the windings, there are as many stable positions

71、 as there are rotor teeth (50 for a 200-step motor). If a motor is de-synchronized, the resulting positional error will always be a whole number of rotor teeth or a multiple of 7.2°. A motor cannot “miss” individual

72、 steps – position errors of </p><p>　　one or two steps must be due to noise, spurious step pulses or a controller fault. Stepper motor drive method ：Stepper motor can not be directly connected to AC or

73、DC power supply frequency on the work, and must use a dedicated stepper motor driver, as shown in Figure 2, which consists of pulse control units, power drive unit, protection unit and other components. Fig crossed the m

74、idpoint of the two units can be surrounded by computer control to achieve. Stepper motor drive unit and the dir</p><p>　　"class server" feature.：The actual role of step angle: in the absence of sub

75、-drive, the user select a different number of phases depends mainly on the stepper motor to meet their own requirements on the step angle. If you use the sub-drive, the user can change the drive number of segments, can d