②两业x大 §5.6开环对数频率特性和时域指标(5) y:180+P(0)=90-arctan arctan 250 250 On S(s+25 +1-22·On 25 y=arctan G(S) VV45+1-252y5分o% s(+25on) 16 3.5 100 3.5 45+1-25 =,.42+1-2=7 10 25 tan 00.20.40.60.8 203040506070S0 y(o§5.6 开环对数频率特性和时域指标(5) wc wn 4 2 4 1 2 180 ( ) j wc n c w w 2 90 arctan c n w 2w arctan 4 2 4 1 2 2 arctan ( 2 ) ( ) 2 n n s s G s w w 2 % / 1 s e s% n s t w 3.5 4 2 4 1 2 3.5 t swc tan 7 2 4 1 2 7 4 2