Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

New to MATLAB?

Problems with idnlgrey object simulation

Asked by Pierangelo

Pierangelo

on 15 Feb 2013

Hi everyone,

I am trying to identify the parameters of a system using a non-linear greyBox object. My system is defined as a state-space and the estimation, run by means of 'pem' command, seems to give good results.

After the estimation process, I use the command 'compare' to have a look on the results with respect to the measured data, and this results good as well.

The problem appears when I simulate the greyBox object on Simulink. The outputs it gives are completely different from the ones given by 'compare', altough I use the same input data.

Why does it happen? Which outputs should I trust more?

Thank you very much.

0 Comments

Pierangelo

Pierangelo

1 Answer

Answer by Arkadiy Turevskiy

Arkadiy Turevskiy

on 15 Feb 2013
Edited by Arkadiy Turevskiy

Arkadiy Turevskiy

on 15 Feb 2013
Accepted answer

This issue was addressed several times previously, here is a link to the question that was answered alerady. You need to set the initial states correctly. Take a look at function for doing that.

HTH.

Arkadiy

1 Comment

Pierangelo

Pierangelo

on 17 Feb 2013

Thank you very much Mr. Turevskiy. You were correct.

Arkadiy Turevskiy

Arkadiy Turevskiy

Contact us