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Entry  Fri Apr 3 15:21:38 2020, Ian MacMillan, Computing, Simulation, Moderinger Simulation 
    Reply  Mon Apr 13 17:30:35 2020, rana, Computing, Simulation, Moderinger Simulation 
    Reply  Wed Apr 22 15:03:59 2020, Ian MacMillan, Computing, Simulation, Moderinger Simulation Moderinger.pdfsimplemoderinger.slx
       Reply  Wed Apr 22 16:41:31 2020, rana, HowTo, Simulation, Moderinger Simulation 
          Reply  Thu Apr 23 13:30:51 2020, Ian MacMillan, HowTo, Simulation, Moderinger Simulation simplemoderinger.slx
             Reply  Fri May 1 03:22:05 2020, Ian MacMillan, HowTo, Simulation, Moderinger Simulation ModeringerSimV2Layout.pdfsimplemoderinger.slx
                Reply  Sun May 3 20:51:14 2020, Ian MacMillan, Computing, Simulation, Moderinger Simulation Moderinger_V2.zip
                   Reply  Tue May 5 13:04:23 2020, aaron, Computing, Simulation, Moderinger Simulation 
                      Reply  Tue Sep 29 02:02:54 2020, Ian MacMillan, Computing, Simulation, Moderinger Simulation ModeRingerLoop.pdfStepPlot.pdfPowerSpectrum.pdfModeRingerSim.zip
                         Reply  Tue Sep 29 11:00:53 2020, aaron, Computing, Simulation, Moderinger Simulation 
                            Reply  Thu Oct 8 00:31:11 2020, Ian MacMillan, Computing, Simulation, Moderinger Simulation ModeRingerLoopDig.pdfModeRingerSim.zip
                               Reply  Thu Oct 15 22:15:11 2020, Ian MacMillan, Computing, Simulation, Moderinger Simulation ModeRingerSpec.pdf
                   Reply  Tue May 5 13:05:36 2020, Ian MacMillan, Computing, Simulation, Moderinger Simulation ModeringerNotebook.ipynb
Message ID: 2571     Entry time: Tue Sep 29 02:02:54 2020     In reply to: 2530     Reply to this: 2572
Author: Ian MacMillan 
Type: Computing 
Category: Simulation 
Subject: Moderinger Simulation 

Working with Aaron's suggestions (In the previous post) we got the mode ringer to converge. Previously the loop would continue to excite the sample to infinity but by fixing the following things we were able to get the step function to converge.

  • Added a discrete zero-pole transfer function after the 100 gain
  • Included the RMS block
  • Disabled zero-crossing detection in the saturation
  • Fixed the sign of the s^2 in the bottom of the plant TF (the i^2 included in s cancels the negative)

The step function represents the excitation of the sample. Ideally, it would excite to the setpoint and stay there but for some reason, it is jumping way past the point before returning. By messing with the gain and the frequency of the low pass filter I could get a variety of results the best is shown below at 50 gain and 40 rad/s.

The power spectrum shown is taken from the spectrum analyzer shown in the loop. It shows what I would expect with a peak around our mode frequency of 1038 Hz.

Next Steps:

  • Figure out how to run the model entirely from a script. (I got this partially working but it is not fully functional)
  • Fix the step function it still seems to be wild and we NEED to fix that before making meaningful progress on this project.
  • Add some sort of error estimation: quantify how good this loop is at measuring what we want.
    • How can we optimize our loop parameters to minimize this error?
  • Make it look pretty (black and white is gross)
Attachment 1: ModeRingerLoop.pdf  35 kB  Uploaded Tue Sep 29 03:08:18 2020  | Hide | Hide all
ModeRingerLoop.pdf
Attachment 2: StepPlot.pdf  68 kB  Uploaded Tue Sep 29 03:08:25 2020  | Hide | Hide all
StepPlot.pdf
Attachment 3: PowerSpectrum.pdf  72 kB  Uploaded Tue Sep 29 03:08:33 2020  | Hide | Hide all
PowerSpectrum.pdf
Attachment 4: ModeRingerSim.zip  511 kB  Uploaded Tue Sep 29 03:19:13 2020
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