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Entry  Mon Mar 8 12:01:02 2021, Paco, Anchal, Summary, training, Investigate how-to XARM locking 
    Reply  Mon Mar 8 12:40:35 2021, gautam, Summary, training, Investigate how-to XARM locking 
    Reply  Mon Mar 8 19:22:56 2021, rana, Summary, SUS, IMC suspension characterization 
       Reply  Thu Mar 11 08:13:24 2021, Paco, Anchal, Update, SUS, IMC First Free Swing Test failed due to typo, restarting now 
          Reply  Tue Mar 16 19:13:09 2021, Paco, Anchal, Update, SUS, First success in Input Matric Diagonalization IMC_InputMatrixDiagonalization.pdfInMatCalcScripts.zip
             Reply  Wed Mar 17 11:57:54 2021, Paco, Anchal, Update, SUS, Tested New Input Matrix for MC1 20210317_MC1_InMATtest.pdfMC1_Input_Matrix_Test.tar.gz
                Reply  Wed Mar 17 16:30:46 2021, Anchal, Update, SUS, Normalized Input Matrices plotted better than SURF students IMC_InputMatrixDiagonalization.pdfNewAndOldMatrices.zip
                   Reply  Thu Mar 18 09:18:49 2021, Paco, Anchal, Update, SUS, Testing of new input matrices with new data MC_Optics_Kicked_Time_Series_1.pdfTEST_Input_Matrix_Diagonalization.pdf
                      Reply  Thu Mar 18 12:46:53 2021, rana, Update, SUS, Testing of new input matrices with new data 
                         Reply  Fri Mar 19 10:49:44 2021, Paco, Anchal, Update, SUS, Trying coil actuation balance 
                            Reply  Mon Mar 22 11:57:21 2021, Paco, Anchal, Update, SUS, Trying coil actuation balance 210322_MC1_ASCY.pdfNewandOldMatrices.tar.gz
                               Reply  Mon Mar 22 15:10:00 2021, rana, Update, SUS, Trying coil actuation balance 
                                  Reply  Mon Mar 22 19:07:50 2021, Paco, Anchal, Update, SUS, Trying coil actuation balance 8x
                                     Reply  Tue Mar 23 09:16:42 2021, Paco, Anchal, Update, Computers, Power cycled C1PSL; restored C1PSL MCWFS1and2PITYAW.pdfMCWFS1and2PITYAW_Zoomed.pdf
                                        Reply  Wed Mar 24 09:23:49 2021, Paco, Update, SUS, MC3 new Input Matrix 
                                           Reply  Thu Mar 25 11:46:31 2021, Paco, Anchal, Update, SUS, MC2 Coil Balancing updates CoilActuationBalancing.ipynb.tar.gzMC2_CoilBalancePITnorm_excSamePIT.pdfMC2_CoilBalanceYAWnorm_excSameYAW.pdf20210325_IMC_CoilBalance.tar.gz
                                              Reply  Thu Mar 25 15:31:24 2021, gautam, Update, IOO, WFS servos 
                                              Reply  Fri Mar 26 11:54:37 2021, Paco, Anchal, Update, SUS, MC2 Coil Balancing updates 
                                                 Reply  Mon Mar 29 10:44:51 2021, Paco, Anchal, Update, SUS, MC2 Coil Balancing updates MC2OutMatCrossCouple_Old-to-It3.pdf20210329_MC2_CrossCoupleTest.tar.gz
                                                    Reply  Mon Mar 29 17:11:54 2021, gautam, Update, SUS, MC2 Coil Balancing updates 
                                                       Reply  Mon Mar 29 17:34:52 2021, rana, Update, SUS, MC2 Coil Balancing updates 
                                                          Reply  Wed Mar 31 22:58:32 2021, Anchal, Paco, Update, SUS, MC2 Coil Balancing Test 
                                                             Reply  Thu Apr 1 13:56:49 2021, Anchal, Paco, Update, SUS, MC2 Coil Balancing Test Results SDistanceFromIdentity.pdfSmatIterations.pdfTestingExcitationAlongYAW.pdf
                                                                Reply  Thu Apr 1 18:01:06 2021, Anchal, Paco, Update, SUS, MC2 Coil Balancing Test Results Success?? SDistanceFromIdentity.pdfSmatIterations.pdfMC2CoilCrossCoupling_opt.png
                                                                   Reply  Thu Apr 1 18:48:45 2021, gautam, Update, SUS, MC2 Coil Balancing Test Results Success?? 
                                                                      Reply  Thu Apr 1 21:13:54 2021, Anchal, Update, SUS, Matrix results, new measurement set to trigger 
                                                                         Reply  Fri Apr 2 14:51:20 2021, Anchal, Update, SUS, Bug found, need to redo the balancing 
                                                                            Reply  Tue Apr 6 18:46:36 2021, Anchal, Paco, Update, SUS, Updates on recent efforts FirstMeasurementPlots.pdf
                                                                               Reply  Wed Apr 7 17:38:51 2021, Anchal, Update, SUS, Trying to uncouple only PIT and YAW first SDistanceFromIdentity.pdfSmatIterations.pdfTimeSeriesPlots.pdfCSDPlots.pdfSmatrixPlots.pdf
                                                                                  Reply  Thu Apr 8 17:04:43 2021, Anchal, Paco, Update, SUS, First Successful Coil Balancing SDistanceFromIdentity.pdfSmatIterations.pdfSmatrixPlots.pdf
                                                                                     Reply  Fri Apr 9 13:13:00 2021, Anchal, Paco, Update, SUS, Faster coil balancing SmatIterations.pdfMC2AllOutmat.txt
                                                                                        Reply  Fri Apr 9 17:41:12 2021, rana, Update, SUS, Faster coil balancing 
                                                                                           Reply  Mon Apr 12 10:07:35 2021, Anchal, Update, SUS, What's F2A?? 
                                                                                              Reply  Tue Apr 13 09:51:22 2021, rana, Update, SUS, What's F2A?? 
                                                                                                 Reply  Wed Apr 14 17:53:38 2021, Anchal, Update, SUS, Plan for calculating filter banks for output matrix aka F2A aka F2P MC2propF2A_UL.pdf
                                                                                                    Reply  Thu Apr 15 11:41:43 2021, Anchal, Update, SUS, Proposed filters for output matrix aka F2A aka F2P MC2propPOSfb.pdf
                                                                                                       Reply  Fri Apr 16 11:36:36 2021, Anchal, Paco, Update, SUS, Tested proposed filters for POS colum in MC2 output matrix 20210416_MC2DCcoilBalancingNoFilters.pdfuncFilters.pdf20210416_MC2DCcoilBalancingWithFilters.pdfuncFilters_v2.pdf20210416_MC2DCcoilBalancingWithFilters_v2.pdf
                                                                                                          Reply  Fri Apr 16 15:47:58 2021, rana, Update, SUS, Tested proposed filters for POS colum in MC2 output matrix 
                                                                                                             Reply  Mon Apr 19 12:18:19 2021, Anchal, Paco, Update, SUS, Tested proposed filters for POS colum in MC2 output matrix CrossCoupleTestForEgToCtFilters.pdfuncFilters.pdfuncFilters_v2.pdf
                                                                                                                Reply  Tue Apr 20 10:52:49 2021, Anchal, Paco, Update, SUS, AC gain coil output balancing for IMC POS2PYuncoupled.pdfPIT2PYuncoupled.pdfMC1YAWexc.pdfMC1PITexc.pdf
                                                                                                                   Reply  Tue Apr 20 18:19:30 2021, Anchal, Update, SUS, MC2 coil balanced at DC MC2_DC_Coil_Balanced_St.pngIMC_F2A_Params_MC2.pdfUploadedPOS_F2A_Filters.pdf
                                                                                                                      Reply  Wed Apr 21 11:38:27 2021, Anchal, Paco, Update, SUS, MC2 Damping Gains Optimized MC2_DampGainStepTestWithNewGains.pngMC2_DampGainStepTestWithOldGains.png
                                                                                                                         Reply  Wed Apr 21 15:50:01 2021, Anchal, Paco, Update, SUS, MC2 Suspension Optimization summary 
                                                                                                                            Reply  Wed Apr 21 18:49:29 2021, rana, Update, SUS, MC2 Suspension Optimization summary 
                                                                                                                               Reply  Thu Apr 22 08:50:21 2021, Anchal, Update, SUS, MC2 Suspension Optimization summary 
                                                                                                                            Reply  Mon Apr 26 18:55:39 2021, Anchal, Paco, Update, SUS, MC2 F2A Filters Tested f2a.pdfIMC_F2A_Params_MC2.pdfMC2_F2A_FilterChar_POS2Ang.pdf
                                                                                                                               Reply  Tue Apr 27 10:05:28 2021, Anchal, Paco, Update, SUS, MC1 and MC3 F2A Filters Tested IMC_F2A_Params_MC1.pdfMC1_POStoAng_CrossCoupling.pdfIMC_F2A_Params_MC3.pdfMC3_POStoAng_CrossCoupling.pdf
                                                                                                                                  Reply  Wed Apr 28 10:56:10 2021, Anchal, Paco, Update, SUS, IMC Filters diagnosed 7x
                                                                                                                                     Reply  Wed Apr 28 17:09:11 2021, Anchal, Update, SUS, Tuned Suspension Parameters uploaded for long term behavior monitoring 
                                                                                                                                     Reply  Thu Apr 29 10:52:56 2021, Anchal, Update, SUS, IMC Trans QPD and WFS loops step response test PIT_OFFSET_ON_MC2.pngYAW_STEP_ON_MC2_complete.png
                                                                                                                                        Reply  Thu Apr 29 18:53:33 2021, Anchal, Update, SUS, IMC Suspension Damping Gains Test MC1_SUSDampGainTest.pdfMC2_SUSDampGainTest.pdfMC3_SUSDampGainTest.pdf
                                                                                                                                           Reply  Mon May 3 16:24:14 2021, Anchal, Update, SUS, IMC Suspension Damping Gains Test Repeated with IMC unlocked MC1_SusDampGainTest.pdfMC2_SusDampGainTest.pdfMC3_SusDampGainTest.pdf
                                                                                                                                              Reply  Wed May 5 09:04:47 2021, Anchal, Update, SUS, New IMC Suspension Damping Gains uploaded for long term testing 
                                                                                                                                                 Reply  Wed May 12 11:45:13 2021, Anchal, Paco, Summary, SUS, New IMC Settings are miserable MC_F_Comparison.pdfMC_TRANS_QPD_Comparison.pdfIMC_REFL_DC_Comparison.pdf
                                                                                                                                                    Reply  Wed Jun 2 09:43:30 2021, Anchal, Paco, Summary, SUS, IMC Settings characterization seismicX.pdfseismicXtoMC_F_TFest.pdfseismicXtoMC_TRANS_PIT_TFest.pdfseismicXtoMC_TRANS_YAW_TFest.pdf
                                                                                                                                                       Reply  Wed Jun 2 16:20:59 2021, Anchal, Paco, Summary, SUS, IMC Suspension gains reverted to old values 
                                                                                                                                                 Reply  Sat May 15 14:54:24 2021, gautam, Update, SUS, IMC settings reverted MC2coilOut.png
                                                                                                                                                    Reply  Thu May 20 10:35:57 2021, Anchal, Update, SUS, IMC settings reverted 
                                                                                                                         Reply  Thu Apr 22 12:17:23 2021, Anchal, Paco, Update, SUS, MC1 and MC3 Suspension Optimization Summary 
                                                                                                                            Reply  Thu Apr 22 14:22:39 2021, gautam, Update, SUS, Settings restored MCdamping.png
                                                                                                                               Reply  Thu Apr 22 15:36:54 2021, Anchal, Update, SUS, Settings restored 
                                                                                                                                  Reply  Thu Apr 22 17:04:17 2021, gautam, Update, SUS, Settings restored 
                                                                                        Reply  Sat Apr 10 10:07:47 2021, rana, Update, SUS, Faster coil balancing 
                                                                         Reply  Fri Apr 2 15:22:54 2021, gautam, Update, SUS, Matrix results, new measurement set to trigger 
                                           Reply  Sun Mar 28 14:16:25 2021, Anchal, Summary, SUS, MC3 new Input Matrix not providing stable loop MC3_Input_Matrix_Diagonalization.pdf
                                              Reply  Mon Mar 29 17:07:17 2021, gautam, Summary, SUS, MC3 new Input Matrix not providing stable loop 
                      Reply  Thu Mar 18 13:12:39 2021, gautam, Update, Computer Scripts / Programs, Omnigraffle vs draw.io 
Message ID: 16007     Entry time: Thu Apr 8 17:04:43 2021     In reply to: 16005     Reply to this: 16009
Author: Anchal, Paco 
Type: Update 
Category: SUS 
Subject: First Successful Coil Balancing 

Today, we finally crossed the last hurdle and got a successful converging coil balancing run. laugh


What was the issue with POS?

  • Position of the MC2 mirror is being sensed using C1:IOO-MC_F_DQ channel which is proportional to the resonant frequency of the locked IMC.
  • However, this sensor is always 180 degrees out of phase of our actuator, the coils.
  • When the coils push the mirror forward, the length of the cavity actually decreases.
  • We added an extra option of providing a sign to the sensors such that -1 will be multiplied to sensed values for sensors which measure in opposite direction to the actuation.
  • This is important, because the feedback is applied to the coil output matrix assuming a particular direction of acctuation.
  • When we gave negative sign for the position sensor, it all started making sense and the algorithm started converging.

First run parameters:

  • We used binwidth of 0.25 Hz and duration of excitation as 41s. This would give welch and csd averaging of 19. We used median averaging to ignore outliers.
  • This iteration was run after PIT and YAW were separetly uncoupled before. We'll post a clean start to end run results in near future.
  • The iteration works in following manner:
    • Define a constant coil matrix C = [[1, 1, 1], [1, 1, -1], [1, -1, 1], [1, -1, -1]] which is ideal coil output matrix.
    • In each iteration, the output matrix Ok is defined as (note @ is the matmul operator):
      Ok = C @ Ak
      where Ak is a 3x3 matrix. A-1 is identity matrix.
    • At the end of each iteration, a sensing matrix is calculated in dimensions sensedDOF x excitedDOF, Sk
    • For next iteration, Ak+1 is calcualted by:
      Ak+1 = Ak - b * (Sk - I)
      where I is the identity matrix.
    • At convergence, the sensing matrix would become same as identity and matrix A will stop updating.
  • For this run, we kept the parameter b to be 0.05. This is similar to the KP parameter in PID loops. It should be between 0 and 1.
  • Since b value was small enough to allow for convergence from the inital point, but later it slowed down the process a lot.
  • Ideally, we should figure out a way to increase this paramter when the coil has been balanced somewhat, to increase the speed of the algorithm.
  • Secondly, we have a code which excites all DOFs at different frequencies directly using excitation channels in coil output matrix using awg.py. But for some reason, the excitation channel for 4th row in the output matrix column only connects intermittantly. Because of this, we can't use this method reliably yet. We can investigate more into it if suggested.

Balancing characteristics:

  • Attachment 1 shows how the distance of sensing matrix falls as iterations increase. We only ran for 50 iterations.
  • Attachment 2 shows how different off-diagonal terms of sensing matrix decreased.
    • Note that POS -> PIT, POS -> YAW and PIT-YAW have settled down to the noise floor.
    • The noise floor can be improved by increasing the excitation amplitude and/or increasing the duration of measurement.
  • Attachment 3 shows the evolution of sensing matrix as iterations move.

Final balanced output matrix:

Final balanced output coil matrix for MC2
POS PIT YAW COILS
1.02956 1.13053 1.19116 UL
1.01210 1.09188 -0.74832 UR
0.98737 -0.85502 0.70485 LR
0.96991 -0.89366 -1.23463 LR
Final Sensing Matrix
  Exc POS Exc PIT Exc YAW
Sens POS 1 -2.96e-2 8.00e-3
Sens PIT 8.58e-4 1 -4.84e-3
Sens YAW 5.97e-4 -1.15e-3 1

Code features and next:

  • Majority of the code is in two files: scripts/SUS/OutMatCalc/MC2crossCoupleTest.py and scripts/SUS/OutMatCalc/crossCoupleTest.py .
  • The code runs from start to end without human involevement and restores the state of channels in any case (error, kyboard interrupt, end of code) using finally statement.
  • Currently, each excitation is done one at a time through LockIn1. As mentioned above, this can be sped up 3 times if we get the awg.py to work reliably.
  • The complete code is in python3 and currently is run through native python3 on allegra (a new debian10 workstation with latest cds-workstation installed).
  • The code can be easily generalized for balancing any optic. Please let us know if we should work on making the generalized optic.
  • We're also working on thinking about increasing b as iterations move forward and the error signal becomes smaller.
  • We can also include the uncertainty in the Sensing matrix measurement to provide a weighted feedback. That way, we can probably increase b more.
Attachment 1: SDistanceFromIdentity.pdf  12 kB  Uploaded Thu Apr 8 18:32:00 2021  | Hide | Hide all
SDistanceFromIdentity.pdf
Attachment 2: SmatIterations.pdf  16 kB  Uploaded Thu Apr 8 18:32:54 2021  | Hide | Hide all
SmatIterations.pdf
Attachment 3: SmatrixPlots.pdf  50 kB  Uploaded Thu Apr 8 18:51:48 2021  | Hide | Hide all
SmatrixPlots.pdf SmatrixPlots.pdf SmatrixPlots.pdf SmatrixPlots.pdf SmatrixPlots.pdf SmatrixPlots.pdf SmatrixPlots.pdf SmatrixPlots.pdf
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