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Entry  Tue Oct 12 12:49:42 2021, Jiri Smetana, General, General, Damping Loop (Point-Mass Pendulums) servo.pngopen_loop.pngclosed_loop.pngnoise.pnglength_change.png
    Reply  Thu Oct 14 04:17:36 2021, Jiri Smetana, General, General, Damping Loop (Point-Mass Pendulums) 8x
Message ID: 41     Entry time: Thu Oct 14 04:17:36 2021     In reply to: 40
Author: Jiri Smetana 
Type: General 
Category: General 
Subject: Damping Loop (Point-Mass Pendulums) 

Here are the DAC and residual displacement spectra for different suspension heights ranging from 450 mm to 600 mm. I aimed to get the Q of the lower resonance close to 5 and the DAC output RMS close to 0.5 V but as this was just tweaking values by hand I didn't get to exactly these values so I'm adding the actual values for reference. The parameters are as follows:

Height [mm] Displacement RMS [nm] DAC Output RMS [V] Q Lower Resonance Q Higher Resonance Driver Resistor {Ohm]
600 560 0.51 5.3 1.5 175
550 580 0.54 5.1 1.4 175
500 610 0.49 5.0 1.4 150
450 630 0.54 5.0 1.4 150
Quote:

Now that I have correct phase and amplitude behaviour for my MIMO state space model of the suspension and the system is being correctly evaluated as stable, I'm uploading the useful plots from my analysis. File names should be fairly self-explanatory. The noise plots are for a total height of 550 mm, or wire lengths of 100 mm per stage. I've also attached a model showing the ground motion for different lengths of the suspension.

 

Attachment 1: disp_600.png  24 kB  Uploaded Thu Oct 14 05:40:16 2021  | Hide | Hide all
disp_600.png
Attachment 2: DAC_600.png  23 kB  Uploaded Thu Oct 14 05:40:24 2021  | Hide | Hide all
DAC_600.png
Attachment 3: disp_550.png  24 kB  Uploaded Thu Oct 14 05:40:33 2021  | Hide | Hide all
disp_550.png
Attachment 4: DAC_550.png  23 kB  Uploaded Thu Oct 14 05:40:46 2021  | Hide | Hide all
DAC_550.png
Attachment 5: disp_500.png  24 kB  Uploaded Thu Oct 14 05:41:16 2021  | Hide | Hide all
disp_500.png
Attachment 6: DAC_500.png  23 kB  Uploaded Thu Oct 14 05:41:30 2021  | Hide | Hide all
DAC_500.png
Attachment 7: disp_450.png  24 kB  Uploaded Thu Oct 14 05:41:43 2021  | Hide | Hide all
disp_450.png
Attachment 8: DAC_450.png  23 kB  Uploaded Thu Oct 14 05:41:50 2021  | Hide | Hide all
DAC_450.png
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