1+G(s)H(s)=0 、根轨迹方程 II(s-E G(s)H(s)=K”. ∏I II(s-=,) ISPIIIs-p (1)模值条件x*1 K s∏-P) (2)相角条件 2∠s-=)-9012s-p=2k+1元k=0三、根轨迹方程 即 (1)模值条件 (2)相角条件 1 G(s)H(s) 0 1 ( ) ( ) ( ) ( ) 1 * 1 n j j m i i s s p s z G s H s K K s z s s p m i i n j j 1 1 | | | | | | m i n j i j s z s p k k 1 1 ( ) 90 (2 1) 0, 1, 1 ( ) ( ) 1 * 1 n j j m i i s s p s z K