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Entry  Sat Nov 5 01:10:29 2011, Suresh, Update, IOO, WFS output matrix measured (open loop) 
    Reply  Mon Nov 7 15:49:26 2011, jamie, Update, IOO, WFS output matrix measured (open loop) 
       Reply  Tue Nov 15 19:59:41 2011, Suresh, Update, IOO, WFS output matrix measured (open loop) 
Message ID: 5819     Entry time: Sat Nov 5 01:10:29 2011     Reply to this: 5834
Author: Suresh 
Type: Update 
Category: IOO 
Subject: WFS output matrix measured (open loop) 

 

The scripts and screens needed to make the MC WFS ouput matrix are once again functional

I corrected the WFS lockins' phases to ensure that the Q outputs are minimised.  Since all the lockins have the same relative phase with respect to the oscillator I found that the same phase works for all of them.  About 90 deg in this case.

The scripts used to make the WFS outmatrix measurement live in /cvs/cds/rtcds/caltech/c1/scripts/MC/WFS

1) setupWFSlockins:   This script makes sure that all the ASC, WFS_ LKIN and WFS_servo filter banks used in this measurement are set up properly.  It also sets the WFS_lockin oscillator to 10 Hz.  There are filter modules in the SIG filter bank of the WFS demodulators. 

2) senseWFSoutMATRX:  This script cycles through the various MC actuators ( MC 1 2 3 : PIT and YAW ) and measures the response of the various ASC sensors (WFS and MC2_TRANS QPD).

3) The data collected by the sensWFSoutMATRX can be analysed with a matlab file called " wfsmatrix3.m " located in a subdirectory under WFS called 'matlab'.   I have added some comments in this file to make it easier to follow.   The output of this file, at the moment, gives only the " Actuation Vectors " for WFS1P, WFS2P, WFS1Y and WFS2Y.  It ignores the MC2TransQPD for now. 

4)  The lockin outputs are given below ( the 'reduceddata' )

             wfs1p      wfs2p      mc2tp      wfs1y      wfs2y     mc2ty

mc1p    0.2926   -0.4086    0.2926    0.0340    0.0064    0.0001
mc2p   -0.2830   -1.3060   -0.2833    0.0628    0.1171   -0.0003
mc3p   -0.3283   -0.3455   -0.3288   -0.0456    0.0275    0.0000
mc1y    0.0440    0.0261    0.0429    0.7204    0.9351   -0.0008
mc2y   -0.1006    0.0850   -0.1036   -1.5509   -0.3882    0.0165
mc3y     0.0150   -0.0832    0.0144    0.1114   -1.0573    0.0006

5) The actuation vectors are given below

Pitch WFS1P WFS2P
MC1 1.00 -0.86
MC2 -0.12 -1
MC3 -0.72 0.09

 

Yaw WFS1Y WFS2Y
MC1 0.16 0.59
MC2 -1.00 0.20
MC3 0.51 -1

6) This measurement was performed with the WFS servo loops open. I will try to close the loops with this matrix and run the script again to measure the output matrix in closed loop.

7) This a.vectors obtained above are significantly different from that obtained a while ago (elog 5668) before the lockin demod phases (relative to each other) were fixed.  This could also be because both are open loop measurements and we might have wandered into the nonlinear regime of the WFS sensors.

 

 

 

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