Unit23,AutomaticControlSystem,自动控制系统,AutomaticControlSystem,AutomaticControlSystem,Anautomaticcontrolsystemisapresetclosed-loopcontrolsystem.Anautomaticcontrolsystemhastwoprocessvariablesassociatedwithit;acontrolledvariableandamanipulatedvariable.Acontrolledvariableistheprocessvariablethatismaintainedataspecifiedvalueorwithinaspecifiedrange.Forexample,inthewatertanklevercontrolsystem,thestoragetanklevelisthecontrolledvariable.Amanipulatedvariableistheprocessvariablethatisactedonbythecontrolsyste
