How to convert symbolic expressions to transfer functions
169 次查看(过去 30 天)
显示 更早的评论
I am encountering the problem of converting a symbolic expression to become a transfer function. Specifically, the linear system I am dealing with contains a non-constant distributed delay term which requires performing an integration to obtain the corresponding transfer function. However, it seems that the integration operator int cannot be applied with tf variables directly.
On the other hand, if there is a way to convert symbolic expressions to transfer functions, then this problem can be easily handled in symbolic setting first.
Thanks a lot
3 个评论
采纳的回答
Walter Roberson
2016-11-2
12 个评论
Paul
2021-2-27
Cool code. Siight mod to also handle the case when symExp is a constant.
syms s
symExp(s) = 5;
ExpFun = matlabFunction(symExp);
ExpFun = str2func(regexprep(func2str(ExpFun), '\.([/^\\*])', '$1'));
TF = tf(ExpFun(tf('s')));
TF
TF =
5
Static gain.
更多回答(2 个)
HyunSang Park
2018-5-28
If you're just trying to find the peak value of the bode magnitude plot, might I suggest avoid using tf altogether? the peak value is when d(G(jw))/dw = 0. You can easily find the derivative with syms, and the plug in the w to the original tf.
0 个评论
Murugan venkatesan
2023-8-7
In order to analyze the bifurcation, the input impedance expression how to plot the bode graph..
1 个评论
Walter Roberson
2023-8-7
I do not understand how people can use your answer to convert symbolic expressions to transfer functions? Could you show how your solution could be used for the example symExp = (s+2)/(s^2+5*s+9); ?
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Assumptions 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!