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Reports until 22:38, Friday 01 January 2016
H1 SUS (ISC)
brett.shapiro@LIGO.ORG - posted 22:38, Friday 01 January 2016 - last comment - 19:36, Tuesday 05 January 2016(24625)
Additional Updates to the quad Matlab model

svn up at .../SusSVN/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production

All current model features are summarized in a table in G1401132.

Update to existing features

The main change in existing features is that the top mass damping now sees both the suspension and the cage, as in real life because we use OSEMs. Consequently, if you input seismic noise to a damped suspension it will enter both mechanically as usual, as well as through the damping loops. See Seismic_Noise_Propagation_2016_01_01.pdf. Page 1 shows longitudinal transfer functions from seismic noise to the test mass with and without the OSEMs seeing the cage. The second page shows the ratio of these transfer functions. Note that the ratio is greater than a factor of 2 at 4.5 Hz. Beyond 10 Hz the maximum is about 20% at about 10.5 Hz.

 

Two new features 

1. Additional inputs and outputs added to reflect the relative nature of the OSEMs - i.e. they measure relative displacements and actuate between two points

2. Suspension point reaction forces

The discussion above is one consequence of the first new feature. Another is that you can now make transfer functions between seismic noise and the top mass OSEMs, which is dramatically different from the seismic noise to top mass transfer function. See Seismic_to_Top_OSEMs_2016_01_01-2.pdf. These are obtainable in the model with the new 'toposem' field in the 'out' structure given by the generate_QUAD_Model_Production function.

The second new feature is that there are now outputs for the suspension point reaction forces on the ISI. These are obtainable in the model with the new 'suspoint' field in the 'out' structure given by the generate_QUAD_Model_Production function. These reaction forces allow us to dynamically couple the quad model to the ISI model. Thus, if we wanted, we can make one big ISI-SUS model.

 

Under-the-hood updates

This update includes significant under-the-hood modifications to how the pieces of the model are put together. Essentially, Simulink files now define the connections and signal flow, where previously this was all done with append/connect commands in the generate script. The motivation for this change is to make the model more extensible and maintanable by humans. The append/connect commands had become virtually unreadable with the dozens of inputs and outputs now in the model. Now someone can look at a more intuitive graphical representation in a simulink file to read or modify how the model is layed out.

There are 4 simulink files defining the 4 possible layouts of the quad model:

1) A single undamped chain - generate_QUAD_SingleChainUndamped_Simulink.slx
2) A single damped chain - generate_QUAD_SingleChainDamped_Simulink.slx
3) Two undamped chains - generate_QUAD_BothChainsUndamped_Simulink.slx
4) Two damped chains - generate_QUAD_BothChainsDamped_Simulink.slx

 

For reference, this is a summary of the history of model revisions in the svn:

generate_QUAD_Model_Production.m

rev 7359: now reads foton files for main chain and reaction damping

rev 7436: Changed hard coded DAMP gains to get the correct values for LHO ETMX specifically.

rev 7508: Restored damping filter choice for P to level 2.1 filters as opposed to Keita's modification. Cleaned up error checking code on foton filter files, and allowed handling of filter archive files and files with the full path.

rev 7639: renaming lho etmy parameter file

rev 7642: Adding custom parameter file for each quad. Each one is a copy of h1etmy at this point, since that one has the most available data.

rev 7646: added ability to read live filters from sites, and ability to load custom parameter files for each suspension

rev 7652: updated to allow damping filters from sites from a specific gps time (in addition to the live reading option)

planned future revision - seismic noise will progate through the damping filters as in real life. i.e the OSEMs are relative sensors and measure the displacement between the cage and the suspension.

rev 7920: big update - added sus point reaction forces, top OSEMs act between cage and sus, replaced append/connect command with simulink files

ssmake4pv2eMB5f_fiber.m

no recent (at least 4 years) functional changes have been made to this file.

* quadopt_fiber.m

- rev 2731: name of file changed to quadopt_fiber.m, removing the date to avoid confusion with Mark Barton's Mathametica files.

- rev 6374: updated based on H1ETM fit in 10089.

- rev 7392: updated pend.ln to provide as-built CM heights according to T1500046

- rev 7912: the update described in this log, where the solidworks values for the inertias of the test mass and pum were put into the model, and the model was then refit.  Same as h1etmy.m.

* h1etmy.m

- rev 7640: created the H1ETMY parameter file based on the fit discussed in 10089.

- rev 7911: the update described in this log, where the solidworks values for the inertias of the test mass and pum were put into the model, and the model was then refit. Same as quadopt_fiber.m.

Non-image files attached to this report
Comments related to this report
brett.shapiro@LIGO.ORG - 10:37, Saturday 02 January 2016 (24638)

The quad model was tagged on the SVN both before and after this update. The tagged models are at 

before this update:
/ligo/svncommon/SusSVN/sus/trunk/Common/SusModelTags/Matlab/quadmodelproduction-rev7652_ssmake4pv2eMB5f_fiber-rev3601_fiber-rev7913_released-2016-01-01.mat
This version reflects the model after the previous recent update discussed in log 24456, which updated the test mass and PUM inertias with solidworks values. No model features were changed in this update.

After this update
/ligo/svncommon/SusSVN/sus/trunk/Common/SusModelTags/Matlab/quadmodelproduction-rev7920_ssmake4pv2eMB5f_fiber-rev3601_fiber-rev7913_released-2016-01-01.mat

The tags were created using the following script:

/ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/tagsusdynamicalmodel.m    rev 7923

jenne.driggers@LIGO.ORG - 16:32, Monday 04 January 2016 (24694)

Just as an FYI, I have done this svn update.

brett.shapiro@LIGO.ORG - 19:36, Tuesday 05 January 2016 (24717)

MInor updates and fixes:

1) The simulink files were generating warnings in Matlab 2012b because they were saved in 2013a. I resaved them in 2012b, recommited, and the problem has gone away. Matlab versions 2013a and 2015b are fine as well. No promises for versions earlier than 2012b.

2) While fixing the simulink diagrams, I added some extra inputs based on a disucssion with Brian Lantz. These are 'osem like' force inputs acting between the top mass and the cage for the purpose of testing the reaction force outputs on the ISI. These will not impact any prior features of the model.

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