机械控制工程课后习题解答(7)

祝守新,邢英杰,韩连英主编 清华大学出版社

图2-39 题2-8图

解

（1）G1 s

G1 s G2 s Y s

Xs1 G1sG2sHsY cs E s G1 s B s Y1 s G2 s H s

E s X s B s X s Y1 s G2 s H s

Y1 s X s Y1 s G2 s H s G1 s G2 s

故

Y1 s G1 s

X1s1 G1sG2sHsG1 s G2 s H s B s

Xs1 G1sG2sHs

G3 s G4 s

E s 1

Xs1 G1sG2sHsG2 s Y s G1 s

Ns1 G1sG2sHsG2 s

Y1 s G1 s G2 s H s

Ns1 G1sG2sHs（2）

G2 s H s B s G3 s

Ns1 G1sG2sHsG4 s

G2 s H s E s

Ns1 G1sG2sHs

2-9 化简如图2-40所示各系统方块图，并求其传递函数。