Reducing fast dynamic poles in a transfer function.

1 view (last 30 days)
Imagine I have a tf that looks something like this: G(s) = 1/((s+70)*(s+5))
Is there some sort of command that can return a transfer fucntion that get's rid of the fastest dynamic pole?
In the example given above my output would be something like this: G(s)=1/(s+5).
Thanks in advance.

Accepted Answer

Paul on 27 Feb 2021
Edited: Paul on 27 Feb 2021
Maybe freqsep() is what you want:
>> G=tf(1,conv([1 5],[1 70]))
G =
s^2 + 75 s + 350
Continuous-time transfer function.
>> [Gs,Gf]=freqsep(G,10)
Gs =
s + 5
Continuous-time transfer function.
Gf =
s + 70
Continuous-time transfer function.
>> bode(Gs,h);
The dc gain of Gs will need to be adjusted to match the dc gain of G if you intend to use Gs as a low frequency approximation to G. This doc page is a good source for starters. There are also additional pages in Robust Control Toolbox for model reduction.
Edward Simpson Songel
Edward Simpson Songel on 28 Feb 2021
P.S. Thanks for the further resources on the subject too.

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by