1 / 2

动态误差

动态误差. 前面讲的是静态误差,是一个静态值 即当 t→∞ 时系统误差的极限值 E(S) 逆变换,是一个时间的函数 时间在 t→∞ 是一个有限的变化过程 实际控制系统的稳态误差往往表现为时间的函数, ----- 即动态误差。. 例:如图系统: 其误差传递函数为: Φxi(s)= E(s)/ Xi(s)=1/[1+G(s)H(s)]. 依据终值定理,时间 t→∞ 对应于 S=0 将上式在 S=0 处展开成泰勒级数形式: Φxi(s)= E(s)/ Xi(s)=1/k 0 +1/k 1 • s+1/k 2 • s2+ …

mariel
Télécharger la présentation

动态误差

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. 动态误差 前面讲的是静态误差,是一个静态值 即当t→∞时系统误差的极限值 E(S)逆变换,是一个时间的函数 时间在t→∞是一个有限的变化过程 实际控制系统的稳态误差往往表现为时间的函数,-----即动态误差。 例:如图系统: 其误差传递函数为: Φxi(s)= E(s)/ Xi(s)=1/[1+G(s)H(s)]

  2. 依据终值定理,时间t→∞对应于S=0 将上式在S=0处展开成泰勒级数形式: Φxi(s)= E(s)/ Xi(s)=1/k0+1/k1•s+1/k2•s2+… 式中ki=1/i! •d(i)Φxi(s)/ds(i)] s=0 k0,k1,k2,…---动态误差系数 E(s)= 1/k0 Xi(s)+1/k1•s Xi(s) +1/k2•s2 Xi(s) +… 此级数的收敛域是S=0的邻域。 则当初始条件为零时,求拉氏逆变换。 ε(t) = 1/k0 Xi(t)+1/k1•d Xi(t)/dt +1/k2•d2Xi(t)/dt2 +… 动态误差与静态误差的关系: εss=limε(t)

More Related