将式(1),(2),(3),(4)联立得: a+Ri()+E() do (t) d+m()=M()-M()(2) E(t=Co(t) M (t=Cmi(t) (4) 消去中间变量(t),E(),M()得电动机输入输出方程为: , do (t) do(t) +OL,fm+rm)-m dt +(Rf+C Ce)om(t) =Cu(t)- aM RM(t) 如果电动机的输出轴配有滚珠轴承并涂高效润滑油,则粘 性摩擦系数f可忽略不计,如果电动机输出轴不带负载,即 M(t=0将式(1),(2),(3),(4)联立得: 消去中间变量          = = + = − + + = ( ) ( ) (4) ( ) ( ) (3) ( ) ( ) ( ) (2) ( ) ( ) ( ) ( ) (1) ( ) M t C i t E t C t f t M t M t d t d t J R i t E t u t d t d i t L m m a a e m m m m C m m a a a a a a    i (t), E (t), M (t) a a m 得电动机输入输出方程为: ( ) (5) ( ) ( ) ( ) ( ) ( ) ( ) ( ) 2 2 R M t d t d M t C u t L R f C C t d t d t L f R J d t d t L J a C C m a a a m m e m m a m a m m a m = − − + + + +    如果电动机的输出轴配有滚珠轴承并涂高效润滑油, 则粘 性摩擦系数 m f 可忽略不计, 如果电动机输出轴不带负载, 即 M (t) = 0 C