Where Can I Find Open Loop Dynamic Process Data?

[Greg Bernhardt]

This is from my sister:

I have an assignment due very soon that requires open loop dynamic process data (at least 75 observations long). I am having a horrible time finding some. Can anyone help?

 

[enigma]

Do you have any other information on what she's looking for?

 

[Greg Bernhardt]

Here is some more info she gave me, possibly the assignment

Data set requisites:
1. Must be discrete-time;
2. Should provide the measured inputs (“Xt”, the controllable factor values)
and output values (“Yt”, the values of the observed quality characteristic
thought to be affected by Xt);
3. Should be at least 75 time units long, where the time unit is defined by
the context of the data.
4. The data must not have been obtained while a (linear) feedback controller
was operating on the process, i.e., this must be “open loop” data. To check
whether you have met this requisite, use Minitab to determine the
cross-correlation function (CCF) between the input series and the output
series. If the CCF at lag zero, lag one, or lag two is significant, you
probably have linear feedback.
5. I prefer data sets for which there is a “story” related about what the
process is, about what are the inputs and outputs, about how they were
measured, etc. Please include this information in your report.
6. Be sure you provide time series data from a dynamic process; not data
from a responsive process.

Thanks all, this is urgent!

 

[enigma]

And this can be on any system at all? No other constraints?

Tell her to contact a local wind tunnel.

I'm pretty certain that velocity tests using pitot tubes are all done on feed forward observations. Velocity as a function of distance along the test airfoil.

Is that sort of like what she's looking for?

EDIT: I'm not sure... from the language, it sounds like she's looking for a control system type application, not a data aquisition type application. Am I wrong?

 

[Andre]

Right, I googled with +"open-loop" +"data set". Thousands of hits but no specific data sets yet

A few more possibilities:
Find a freshman physics. He must have done a few practical tests with open loop systems.
Generate a test of an open loop system yourself perhaps by measuring system response on a jump input on a simple band filter or something like that.