用拉氏变换求取辘的ZS,r E(s) st e(le O R(S)=E(SH(S) r(t)=onj ojo H (SE(Seds elt E H(S H(SE(S)一 .用拉氏变换求取系统的z.s.r H s E s e ds j r t R s E s H s E s e t e dt j j s t s t   +  −  −  − = = =    ( ) ( ) 2 1 ( ) ( ) ( ) ( ) ( ) ( ) 0 L H(s) −1 L e(t) E(s) H(s)E(s) r(t)