机械工程测试技术基础答案(第三版)(14)

给需要的朋友!

wd = 2p/td = 1rad/s

wn=

=

»1.024rad/s

3wn23.15

所以H(s)=2 =22

s+2zwns+wns+0.44s+1.05

3wn23.15

H(w)=2=22

wn-w+j2zwnw1.05-w+j0.44w

A(w)=

2z

j(w)=-arctan

w

wn

2

æwö1-ç÷èwnø

当w = wn时，

A(wn)=

»6.82

j(wn)=-90°