Simulink transfer function with sinusoidal parameters

Hi

I need to design a transfer function in the following form: 1 / (s^2 + K*s) where K is scalar and varies sinusoidal; the denominator should look like [1 K 0].

What would be the way to implement this behavior ?

Thanks

Answer 1

[Azzi Abdelmalek]

The corresponding equation is

d^2y(t)/dt^2+k.dy(t)/dt+y(t)=x(t)

where

• x(t) is the input of your system
• y(t) is its output

you have just to replace k by sin(t) using a clock and a sine wave block. and use derivative and integrator block instead of transfer function block to realize your model

or you can do this

from your transfer function

Y(p)(P^2+Kp+1)=X(p)

P^2 Y(p) + K p Y(p)+ 1=X(p)

Y(p)+K Y(p)/p+Y(p)/p^2=X(p)/p^2

this can be represented by

[Azzi Abdelmalek]

realize 1/p with continuous transfer function (not integrator)

Answer 2

[River Rock]

Thanks for your great response

I had to adapt the diagram for the denominator [1 K 0], as you use [1 K 1] in your example.

Why did you use the gain blocks?

[Azzi Abdelmalek]

This model is one of my own files. I 've adapted it for your question, I 've set the gain to 1. Then you can remove the two gain block

[Azzi Abdelmalek]

If you use D=[1 K], remove the first sum and 1/p blocks