一、什么是隨動系統
隨動系統servo system，是一種(zhong)反饋控制(zhi)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。在(zai)這種(zhong)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)中(zhong)(zhong)，輸出(chu)(chu)量是機械位移、速度(du)或(huo)者加(jia)速度(du)。因(yin)此隨(sui)(sui)(sui)動(dong)(dong)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)這一術語，與位置(zhi)或(huo)速度(du)，或(huo)加(jia)速度(du)控制(zhi)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)是同義語。在(zai)隨(sui)(sui)(sui)動(dong)(dong)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)中(zhong)(zhong)，有一類，它的(de)(de)參(can)考輸入(ru)不(bu)是時間的(de)(de)解(jie)析函數，如何變化(hua)(hua)(hua)(hua)事先并不(bu)知道（隨(sui)(sui)(sui)著時間任意變化(hua)(hua)(hua)(hua)）。控制(zhi)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)的(de)(de)任務是在(zai)各種(zhong)情況下保證輸出(chu)(chu)以(yi)一定(ding)精度(du)跟(gen)隨(sui)(sui)(sui)著參(can)考輸入(ru)的(de)(de)變化(hua)(hua)(hua)(hua)而(er)(er)變化(hua)(hua)(hua)(hua)。微機位置(zhi)伺服系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)概述在(zai)自動(dong)(dong)控制(zhi)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)中(zhong)(zhong)，把(ba)輸出(chu)(chu)量能夠(gou)以(yi)一定(ding)準確度(du)跟(gen)隨(sui)(sui)(sui)輸入(ru)量的(de)(de)變化(hua)(hua)(hua)(hua)而(er)(er)變化(hua)(hua)(hua)(hua)的(de)(de)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)稱為隨(sui)(sui)(sui)動(dong)(dong)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)，亦稱伺服系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。在(zai)控制(zhi)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)中(zhong)(zhong)若(ruo)給(gei)定(ding)的(de)(de)輸入(ru)信號是預(yu)先未知且隨(sui)(sui)(sui)時間變化(hua)(hua)(hua)(hua)的(de)(de)并且系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)的(de)(de)輸出(chu)(chu)量隨(sui)(sui)(sui)輸入(ru)量的(de)(de)變化(hua)(hua)(hua)(hua)而(er)(er)變化(hua)(hua)(hua)(hua)這種(zhong)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)就稱為隨(sui)(sui)(sui)動(dong)(dong)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。快(kuai)速跟(gen)蹤和(he)準確定(ding)位是隨(sui)(sui)(sui)動(dong)(dong)系(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)的(de)(de)兩個重要(yao)技術指(zhi)標(biao)。
二、隨動系統的特點
改變(bian)電(dian)(dian)動(dong)機(ji)電(dian)(dian)樞(shu)回(hui)路(lu)總電(dian)(dian)阻調(diao)速(su)(su)方法(fa)最早被采(cai)(cai)用(yong)。該(gai)調(diao)速(su)(su)系(xi)統的特點是：設計、安(an)裝、調(diao)試方便、設備線路(lu)簡單，投(tou)資小；缺點是：電(dian)(dian)動(dong)機(ji)的機(ji)械特性(xing)變(bian)軟，耗(hao)能(neng)多；調(diao)速(su)(su)范圍(wei)小，不平(ping)滑。減弱電(dian)(dian)動(dong)機(ji)勵磁磁通調(diao)速(su)(su)方法(fa)調(diao)速(su)(su)范圍(wei)不大，電(dian)(dian)動(dong)機(ji)的機(ji)械特性(xing)變(bian)軟，只(zhi)要求在額定轉速(su)(su)以上升速(su)(su)時采(cai)(cai)用(yong)。
改變電(dian)動(dong)機的(de)端(duan)電(dian)壓(ya)的(de)調速(su)(su)方法(fa)調速(su)(su)系統(tong)調速(su)(su)范圍大、平滑(hua)性好。常采(cai)用(yong)的(de)調壓(ya)調速(su)(su)方法(fa)是(shi)：采(cai)用(yong)晶閘管可控(kong)整流裝置供電(dian)給直流電(dian)動(dong)機的(de)調速(su)(su)系統(tong)。
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
由直流電(dian)(dian)(dian)動(dong)(dong)機(ji)的特性方程可知，電(dian)(dian)(dian)動(dong)(dong)機(ji)轉速(su)隨著負載增(zeng)加而下降(jiang)的原因是由于電(dian)(dian)(dian)樞回路(lu)電(dian)(dian)(dian)壓降(jiang)增(zeng)大之(zhi)故。如果能夠做(zuo)到隨著負載增(zeng)加轉速(su)有(you)所下降(jiang)時(shi)及時(shi)調整晶閘管的控(kong)制角，提(ti)高整流電(dian)(dian)(dian)源的輸出電(dian)(dian)(dian)壓，電(dian)(dian)(dian)動(dong)(dong)機(ji)的轉速(su)就會有(you)一定的回升。這就必須依靠轉速(su)的閉環(huan)控(kong)制。
2、調速系統的靜特性
分析系(xi)統(tong)穩(wen)態(tai)特性的(de)(de)目的(de)(de)，就是要找出減少靜態(tai)速降，擴大(da)調速范圍的(de)(de)途徑，改善(shan)系(xi)統(tong)的(de)(de)調速性能。
