how to plot frequency domain response in simulink ?

Hello,

I am giving continuous time signal and i am plotting time domain response on scope in siulink, but i want to analyse frequency response of same continuous time signal.

how should i analyse frequency response of continuous time signal in simulink ?

Answer 1

[Azzi Abdelmalek]

You can use Spectrum Analyzer if you have a DSP system toolbox

[Aniket]

means i can directly connect spectrum analyzer instaed of time scope ?

[Aniket]

and other question is how should i plot output sensitivity in simulink ?

[Azzi Abdelmalek]

When you said time domain response, do you mean you need to analyse a system or just a signal?

[Aniket]

analyse a system , i am working on LQG design controller

[Azzi Abdelmalek]

Then connect the system input and output to the spectrum Analyser

[Aniket]

Thank you,

Do you have any idea about how to plot bode diagram from simulink

[Pruthveeraj Mali]

Can you send me LQG model? so that ease to help you

Answer 2

[Arkadiy Turevskiy]

You can also use the tool called Simulink Control Design. It lets you linearize your model analytically, so you can compute and plot a transfer function from any input to any output. It also has the functionality called frequency response estimation, which is exactly what you are trying to do: it lets you inject a time signal into any input, and calculates and plots the frequency response from that input to any output. Does all the signal logging, fft calculations for you.

For exact linearization, see more on this page we put together for linearization. For frequency-response estimation, see the section of the page that says "frequency response estimation".

Arkadiy

[Aniket]

Thank you

and can i plot output sensitivity, complimentry sensitivity using this tool ?

[Arkadiy Turevskiy]

sensitivity and complementary sensitivity are just two specific transfer functions, so yes, you can caclulate and plot them - you'll just need to setup linearization input and output points correctly.

[Aniket]

hello Here is my simulink model , i am not getting where i have to put linearization input , output points points for to plot sensitivity and output sensitivity function , could please tell where should i put points ?

like output sensitivity in equation is So = 1 / (1 + G * C) G is plant and C is controller

[Arkadiy Turevskiy]

explained here.