幅值条件和相角条件的几何意义 例如,若S是根轨迹上的点,则s满足 ∠G(s)H(Sn) 0 =∠(-x,)∑∠(-p) p2 =B1-(a1+a2+ax3) =土80°(2k+1,k=0,l,2, Z p1 II(so-Pi K g 3 II(so i=l p3180 ( 2k 1 ), k 0,1,2, ( ) ( s z ) ( s p ) G( s )H( s ) s s 1 1 2 3 3 i 1 0 1 0 i 0 0 0 0 =   + = = − + + =  − −  −  = =     例如，若 是根轨迹上的点，则 满 足 幅值条件和相角条件的几何意义 1 1 2 3 m i 1 0 i n i 1 0 i g b a a a (s z ) (s p ) K = − − =   = = × p2 × p1 s0 × p3 O z1 1 1 3 2 1 a 2 a a3 1 b j