K,→0 乃(K,=0) [s] 0P3 ←-Kr Z1(K,=o)乃 /K,O)P(K,=0) 02 a OPA P4(K,=0) 图6-17非最小相位系统的根轨迹 1313 j  [s] ( ) Z1 Kr =  ( 0) P2 Kr = ( 0) P3 Kr = 2 -1 0 1 Kr →    Kr 1 ( 0) P4 Kr = P3  P4  Kr →  ( 0) P1 Kr = 图6-17 非最小相位系统的根轨迹