0 R (t 0 L R图 R=3.L=1.C=1/2 MODERN CONTROL SYSTEMMODERN CONTROL SYSTEM 8 (t) 0 1 1 1 0 C u L R L C                   − ＋ － x＝ x y = 0 Rx R = 3, L = 1,C = 1/ 2