Get transfer function from data and known input
9 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
Or Perez
el 31 de Mayo de 2022
Comentada: Star Strider
el 31 de Mayo de 2022
Hey there :)
So this is what I know about the system:
- The system is a second order system
- The input is u(t) = 2·1(t)
- A structure has been given to me with y(t) against t(sec)
When I plot it I get this graph:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1017175/image.png)
What I need:
I need to find the trasnfer function for the conditions above.
I know that I can find it analytically by finding Mp, Zeta, Wn and etc...
Is there a shortcut to find the transfer function?
I tried working with systemIdentification and tfest but both ways ask me to give the number of poles and zeros which I don't know + I can't tell the program that the data is for the input u(t) = 2·1(t).
This is what I get from systemIdentification tool, but I might be using it wrong:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1017180/image.png)
The code:
data = iddata(Struc.y, Struc.time, 1*10^(-4));
plot(Struc.time, Struc.y, '--r');
hold 'all'
step(tf1)
%tf1 is generated from the systemIdentification tool and data
tnx!
2 comentarios
Walter Roberson
el 31 de Mayo de 2022
Editada: Walter Roberson
el 31 de Mayo de 2022
number of poles is 0 unless there are some for negative or complex values.
number of zeros is possibly 1, unless there are more at negative or complex
That said, if you were to subtract approximately 15 you might get an infinite number of 0s.
Walter Roberson
el 31 de Mayo de 2022
Editada: Walter Roberson
el 31 de Mayo de 2022
What would you get for something like 12*sin(t)*exp(-t)+15 ?
Respuesta aceptada
Star Strider
el 31 de Mayo de 2022
4 comentarios
Star Strider
el 31 de Mayo de 2022
My pleasure!
If my Answer helped you solve your problem, please Accept it!
.
Más respuestas (0)
Ver también
Categorías
Más información sobre Transfer Function Models en Help Center y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!