一、什么是隨動系統
隨動系統servo system，是一種反饋控制(zhi)系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)。在這種系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)中，輸(shu)(shu)(shu)出(chu)量(liang)是機械位移、速(su)度(du)或者加(jia)速(su)度(du)。因此隨(sui)(sui)動系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)這一術語，與位置(zhi)或速(su)度(du)，或加(jia)速(su)度(du)控制(zhi)系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)是同義語。在隨(sui)(sui)動系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)中，有(you)一類(lei)，它的(de)(de)參(can)考(kao)輸(shu)(shu)(shu)入(ru)不是時(shi)間(jian)的(de)(de)解(jie)析函數，如(ru)何(he)變化(hua)(hua)事先并不知道（隨(sui)(sui)著(zhu)時(shi)間(jian)任(ren)(ren)意變化(hua)(hua)）。控制(zhi)系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)任(ren)(ren)務是在各種情況下保證輸(shu)(shu)(shu)出(chu)以一定(ding)精度(du)跟(gen)隨(sui)(sui)著(zhu)參(can)考(kao)輸(shu)(shu)(shu)入(ru)的(de)(de)變化(hua)(hua)而(er)變化(hua)(hua)。微機位置(zhi)伺(si)服(fu)系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)概述(shu)在自動控制(zhi)系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)中，把輸(shu)(shu)(shu)出(chu)量(liang)能(neng)夠以一定(ding)準確(que)(que)度(du)跟(gen)隨(sui)(sui)輸(shu)(shu)(shu)入(ru)量(liang)的(de)(de)變化(hua)(hua)而(er)變化(hua)(hua)的(de)(de)系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)稱(cheng)(cheng)為隨(sui)(sui)動系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)，亦稱(cheng)(cheng)伺(si)服(fu)系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)。在控制(zhi)系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)中若(ruo)給定(ding)的(de)(de)輸(shu)(shu)(shu)入(ru)信號是預先未知且隨(sui)(sui)時(shi)間(jian)變化(hua)(hua)的(de)(de)并且系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)輸(shu)(shu)(shu)出(chu)量(liang)隨(sui)(sui)輸(shu)(shu)(shu)入(ru)量(liang)的(de)(de)變化(hua)(hua)而(er)變化(hua)(hua)這種系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)就稱(cheng)(cheng)為隨(sui)(sui)動系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)。快速(su)跟(gen)蹤和(he)準確(que)(que)定(ding)位是隨(sui)(sui)動系(xi)(xi)(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)兩個重(zhong)要技術指(zhi)標。
二、隨動系統的特點
改變電(dian)(dian)動機(ji)電(dian)(dian)樞回路總電(dian)(dian)阻調(diao)速(su)(su)方法最早被(bei)采(cai)用。該調(diao)速(su)(su)系統的特(te)點(dian)(dian)是(shi)：設計、安裝、調(diao)試方便、設備線路簡單，投資小；缺點(dian)(dian)是(shi)：電(dian)(dian)動機(ji)的機(ji)械特(te)性(xing)(xing)變軟，耗能(neng)多；調(diao)速(su)(su)范圍小，不(bu)平滑(hua)。減弱電(dian)(dian)動機(ji)勵磁磁通調(diao)速(su)(su)方法調(diao)速(su)(su)范圍不(bu)大，電(dian)(dian)動機(ji)的機(ji)械特(te)性(xing)(xing)變軟，只(zhi)要求在(zai)額定(ding)轉(zhuan)速(su)(su)以上(shang)升速(su)(su)時采(cai)用。
改變電(dian)動機的端(duan)電(dian)壓(ya)的調(diao)(diao)(diao)(diao)速方法(fa)調(diao)(diao)(diao)(diao)速系(xi)統(tong)調(diao)(diao)(diao)(diao)速范圍(wei)大、平滑性好。常采(cai)用(yong)的調(diao)(diao)(diao)(diao)壓(ya)調(diao)(diao)(diao)(diao)速方法(fa)是：采(cai)用(yong)晶(jing)閘(zha)管可控整流裝置供電(dian)給(gei)直流電(dian)動機的調(diao)(diao)(diao)(diao)速系(xi)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(you)直(zhi)流(liu)電動(dong)機(ji)的(de)特性(xing)方程可知，電動(dong)機(ji)轉速(su)(su)隨著負載增(zeng)(zeng)加而下降(jiang)(jiang)的(de)原因是由(you)于電樞回路電壓降(jiang)(jiang)增(zeng)(zeng)大之故。如果能夠做到隨著負載增(zeng)(zeng)加轉速(su)(su)有(you)所下降(jiang)(jiang)時及時調整晶閘管的(de)控制角，提高整流(liu)電源的(de)輸出(chu)電壓，電動(dong)機(ji)的(de)轉速(su)(su)就會有(you)一定的(de)回升。這就必(bi)須(xu)依靠轉速(su)(su)的(de)閉環控制。
2、調速系統的靜特性
分(fen)析系統(tong)穩態特(te)性的(de)目的(de)，就是要找出(chu)減少靜態速降(jiang)，擴大調速范圍的(de)途徑，改(gai)善系統(tong)的(de)調速性能。
