CDS 110b: Robust Stability: Difference between revisions

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'''Q: Is there any way to bode plot (exp(-ts)-1) in MATLAB?'''
'''Q: Is there any way to bode plot (exp(-ts)-1) in MATLAB?'''
<blockquote>
<blockquote>
You can't use the 'bode' command, since the exponential makes that expression not a polynomial transfer function.  If all you're interested in is the magnitude though, (as in this week's homework set) you can plot that explicitly, as follows.  (This should look familiar for those of you who took 110A, since we had you do a bode plot without using the bode command a long time ago.)
<p>You can't use the 'bode' command, since the exponential makes that expression not a polynomial transfer function.  If all you're interested in is the magnitude though, (as in this week's homework set) you can plot that explicitly, as follows.  (This should look familiar for those of you who took 110A, since we had you do a bode plot without using the bode command a long time ago.)</p>


<pre>
omega = logspace(some_start, some_end, some_num);
omega = logspace(some_start, some_end, some_num);
loglog(omega, abs(exp(-t*i*omega)-1));
loglog(omega, abs(exp(-t*i*omega)-1));
</pre>


I recommend doing help logspace and help loglog to understand what those functions do -- they're not too tricky.
<p>I recommend doing help logspace and help loglog to understand what those functions do -- they're not too tricky.</p>
</blockquote>
</blockquote>

Revision as of 19:26, 28 February 2006

WARNING: This page is for a previous year.
See current course homepage to find most recent page available.
Course Home L7-2: Sensitivity L8-1: Robust Stability L9-1: Robust Perf Schedule

This lecture describes how to model uncertainty in control and provides conditions for checking robust stability in this framework.

Lecture Outline

  1. Modeling uncertainty
  2. Robust stability
  3. Preview: robust performance

Lecture Materials

References and Further Reading

Frequently Asked Questions

Q: Is there any way to bode plot (exp(-ts)-1) in MATLAB?

You can't use the 'bode' command, since the exponential makes that expression not a polynomial transfer function. If all you're interested in is the magnitude though, (as in this week's homework set) you can plot that explicitly, as follows. (This should look familiar for those of you who took 110A, since we had you do a bode plot without using the bode command a long time ago.)

omega = logspace(some_start, some_end, some_num);
loglog(omega, abs(exp(-t*i*omega)-1));

I recommend doing help logspace and help loglog to understand what those functions do -- they're not too tricky.