[例2]稳态误差 试求单位反馈系统当输入信号为单位阶跃函数和单位斜坡函数时的稳态误差 20 G(s)= (0.5s+1)(0.04s+1) e=lim1+G(s)H(s) R(S) School of Mechanical Engineering ME369-lecture 6.3 Shanghai Jiao Tong University Fal12015 稳态误差系数一定义 e=lime(t)=lims- R(s) 1-+00 s→01+G(s)H(s) 单位阶跃输入Rs)=I 11 1 e=1+G(s)H(s)s1+G(0)H(0)1+K 稳态位置误差系数 单位斜坡输入风)-宁 11 1 1 e=lims +G(5)H(s)s2 limsG(s)H(s) 稳态速度误差系数 单位抛物线输入 RS)-了 1 1 1 .=吗'1+GsH95- ims2G(s)H(s)K。稳态加速度误差系数 +0 School of Mechanical Engineering ME369-lecture 6.3 Shanghai Jiao Tong University Fall 2015 44 ME369-lecture 6.3 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 20 ( ) (0.5 1)(0.04 1) G s s s    试求单位反馈系统当输入信号为单位阶跃函数和单位斜坡函数时的稳态误差 0 1 lim ( ) 1 ( ) ( ) ss s e s R s  G s H s   [例2]稳态误差 ME369-lecture 6.3 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 0 (0) ( 1 1 lim 1 ( ) ( ) 1 0) 1 ss s e s  G s H s s G H    0 1 lim ( ) lim ( ) 1 ( ) ( ) ss t s e e t s R s   G s H s    1 1 K p   1 R s( ) s 单位阶跃输入  稳态位置误差系数 0 0 2 1 1 lim 1 ( ) ( ) lim ( ) ( 1 ) ss s s e s G s H s s sG s H s      2 1 R s( ) s 单位斜坡输入  稳态速度误差系数 0 2 0 3 1 1 lim 1 ( ) ( ) lim 1 ( ) ( ) s ss s s G e s  G s H s s s H s     单位抛物线输入 3 1 R s( ) s  1 K v  1 K a  稳态误差系数 —定义 稳态加速度误差系数