传递函数定义（续） x,(t)=6(t) 一X(s)=L[6(t)]=1 x.(t) X(s) G(s)= X（⑤=X.(s)=[g】 X,(s) 系统的脉冲响应函数(Impulse--Response Function) School of Mechanical Engineering ME369-Lecture 4.1 Shanghai Jiao Tong University Fall 2015 例1]求传递函数 0 0 M+B d0_血， dr +K[玉)-=f) d在0，) K()x+)=0 ● School of Mechanical Engineering ME369-Lecture 4.1 Shanghai Jiao Tong University Fall 2015 33 ME369-Lecture 4.1 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University ( ) ( ) ( ) [ ] ( ) ( ) c c r X s G s X s L s g t X    x (t) (t) r   x (t) c Xr (s)  L[ (t)] 1 X (s) c 系统的脉冲响应函数（Impulse-Response Function） 传递函数定义（续） ME369-Lecture 4.1 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University [例1]求传递函数   2 1 1 2 1 1 1 2 2 ( ) ( ) ( ) ( ) ( ) ( ) d x t dx t dx t M B K x t x t f t dt dt dt              2 2 1 2 2 1 1 2 2 2 2 ( ) ( ) ( ) ( ) ( ) ( ) 0 d x t dx t dx t M B K x t x t K x t dt dt dt            