一、什么是隨動系統
隨動系統servo system，是一(yi)種反饋(kui)控(kong)制系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。在(zai)(zai)這種系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)中，輸(shu)出(chu)(chu)量(liang)是機(ji)械(xie)位(wei)移(yi)、速(su)度或者加速(su)度。因此隨(sui)動(dong)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)這一(yi)術語，與位(wei)置或速(su)度，或加速(su)度控(kong)制系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)是同(tong)義語。在(zai)(zai)隨(sui)動(dong)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)中，有一(yi)類，它的(de)(de)(de)(de)參考(kao)輸(shu)入(ru)不(bu)是時(shi)間的(de)(de)(de)(de)解析函數，如(ru)何變(bian)化事(shi)先(xian)并不(bu)知道（隨(sui)著(zhu)時(shi)間任意(yi)變(bian)化）。控(kong)制系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)任務是在(zai)(zai)各種情況下(xia)保證輸(shu)出(chu)(chu)以(yi)(yi)一(yi)定(ding)精度跟(gen)隨(sui)著(zhu)參考(kao)輸(shu)入(ru)的(de)(de)(de)(de)變(bian)化而變(bian)化。微機(ji)位(wei)置伺服系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)概述在(zai)(zai)自動(dong)控(kong)制系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)中，把輸(shu)出(chu)(chu)量(liang)能夠以(yi)(yi)一(yi)定(ding)準(zhun)確度跟(gen)隨(sui)輸(shu)入(ru)量(liang)的(de)(de)(de)(de)變(bian)化而變(bian)化的(de)(de)(de)(de)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)稱為(wei)隨(sui)動(dong)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)，亦稱伺服系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。在(zai)(zai)控(kong)制系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)中若給定(ding)的(de)(de)(de)(de)輸(shu)入(ru)信號是預(yu)先(xian)未(wei)知且隨(sui)時(shi)間變(bian)化的(de)(de)(de)(de)并且系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)輸(shu)出(chu)(chu)量(liang)隨(sui)輸(shu)入(ru)量(liang)的(de)(de)(de)(de)變(bian)化而變(bian)化這種系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)就稱為(wei)隨(sui)動(dong)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。快速(su)跟(gen)蹤和(he)準(zhun)確定(ding)位(wei)是隨(sui)動(dong)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)兩個重(zhong)要技術指(zhi)標(biao)。
二、隨動系統的特點
改變(bian)電(dian)動機(ji)(ji)電(dian)樞回路總(zong)電(dian)阻(zu)調(diao)速方法(fa)最早被(bei)采用(yong)。該調(diao)速系統(tong)的特點是(shi)：設計、安裝、調(diao)試方便、設備線路簡單，投(tou)資小(xiao)；缺點是(shi)：電(dian)動機(ji)(ji)的機(ji)(ji)械(xie)(xie)特性變(bian)軟(ruan)(ruan)，耗能多；調(diao)速范(fan)圍小(xiao)，不平滑。減弱電(dian)動機(ji)(ji)勵磁(ci)磁(ci)通(tong)調(diao)速方法(fa)調(diao)速范(fan)圍不大，電(dian)動機(ji)(ji)的機(ji)(ji)械(xie)(xie)特性變(bian)軟(ruan)(ruan)，只(zhi)要求在(zai)額定轉速以上升速時采用(yong)。
改變電(dian)動機的端電(dian)壓的調(diao)(diao)(diao)速(su)(su)方(fang)法(fa)調(diao)(diao)(diao)速(su)(su)系(xi)統調(diao)(diao)(diao)速(su)(su)范圍大、平滑性好。常采(cai)用的調(diao)(diao)(diao)壓調(diao)(diao)(diao)速(su)(su)方(fang)法(fa)是：采(cai)用晶閘管(guan)可控整流裝置(zhi)供電(dian)給直流電(dian)動機的調(diao)(diao)(diao)速(su)(su)系(xi)統。
三、隨動系統的基本形式
1、轉速負反饋調速系統的組成、原理及其靜特性
由(you)直流(liu)(liu)電(dian)動(dong)機(ji)的(de)(de)特性方程(cheng)可知，電(dian)動(dong)機(ji)轉速(su)隨(sui)著(zhu)負(fu)載(zai)增(zeng)(zeng)加而下(xia)降(jiang)的(de)(de)原因是由(you)于電(dian)樞回路電(dian)壓降(jiang)增(zeng)(zeng)大(da)之故。如果能夠做到隨(sui)著(zhu)負(fu)載(zai)增(zeng)(zeng)加轉速(su)有(you)(you)所下(xia)降(jiang)時(shi)及(ji)時(shi)調(diao)整晶閘管的(de)(de)控制角，提高整流(liu)(liu)電(dian)源的(de)(de)輸出電(dian)壓，電(dian)動(dong)機(ji)的(de)(de)轉速(su)就(jiu)會有(you)(you)一定的(de)(de)回升。這就(jiu)必須(xu)依(yi)靠轉速(su)的(de)(de)閉環控制。
2、調速系統的靜特性
分(fen)析系(xi)統(tong)(tong)穩態特(te)性(xing)的目的，就是(shi)要找出減少(shao)靜(jing)態速降，擴大(da)調(diao)速范圍的途徑，改(gai)善系(xi)統(tong)(tong)的調(diao)速性(xing)能。
