Edgard, Brian.
Following up on the fits for the SR3 estimator. I ran the plotall scripts on the transfer functions we took last Friday [see 84003]. Then ran the attached code to fit the transfer functions.
Figure 1 shows the ISI-M1 fitted transfer function. The Q-factors for the fit were tweaked by hand so I could get a decent fit. The exported M1 to M1 transfer function is shown in the second attachment. I decided it should have the same poles as the ISI one, and the gain was fit so the estimator matches the high-frequency behavior of the measured transfer function. The choice to share poles is because the math indicates that it will lead to some potential modeling errors cancelling out.
The pole information for the two filters is:
Pole Damping Frequency Time Constant
(rad/seconds) (seconds)
-4.38e-02 + 6.38e+00i 6.86e-03 6.38e+00 2.28e+01
-4.38e-02 - 6.38e+00i 6.86e-03 6.38e+00 2.28e+01
-7.64e-02 + 1.44e+01i 5.30e-03 1.44e+01 1.31e+01
-7.64e-02 - 1.44e+01i 5.30e-03 1.44e+01 1.31e+01
-2.97e-02 + 2.13e+01i 1.39e-03 2.13e+01 3.37e+01
-2.97e-02 - 2.13e+01i 1.39e-03 2.13e+01 3.37e+01
And the zpk strings (in MATLAB format) are:
ISI to M1:
zpk([-0.068+20.398i,-0.068-20.398i,-0.099+11.454i,-0.099-11.454i,0,0],[-0.03+21.271i,-0.03-21.271i,-0.076+14.435i,-0.076-14.435i,-0.044+6.384i,-0.044-6.384i],-0.75)'
M1 to M1:
zpk([4745.079,-0.089+8.28i,-0.089-8.28i,-0.113+19.058i,-0.113-19.058i],[-0.03+21.271i,-0.03-21.271i,-0.076+14.435i,-0.076-14.435i,-0.044+6.384i,-0.044-6.384i],-0.015)
I did the fits by using the spectrumest function in MATLAB (which is sadly not available in 2019a). The long term plan is to switch to one of the many python fitting tools that people like for the fits. The code is attached to this logpost for bookkeeping
I added a script to
... SusSVN/sus/trunk/HLTS/Common/FilterDesign/Estimator/
that uses autoquack to add the fits to the Foton file for H1 SR3.
The script is named
make_SR3_yaw_model.m
and it uses the fits mentioned in the logpost above, which are contained in the same folder, as
fits_H1SR3_2025-04-21.mat
The changes are current to the sus svn under revision 12277.
These filters have been loaded into the SR3_M1_YAW_EST_MODL_SUSP_Y_2GAP and SR3_M1_YAW_EST_MODL_DRV_Y_2GAP.
Attached are the plots that came up when I ran the matlab script that loaded them in, along with the log message that was created and the coeff diffs.
Small modification that will not affect the estimator test, so it is here for bookeeping.
I didn't clean up the zpk for the M1 to M1 transfer function, so it has a high frequency zero that is due to floating point errors in my fit.
the real zpks should be:
ST1 to M1
'zpk([-0.068+20.398i,-0.068-20.398i,-0.099+11.454i,-0.099-11.454i,0,0],[-0.03+21.271i,-0.03-21.271i,-0.076+14.435i,-0.076-14.435i,-0.044+6.384i,-0.044-6.384i],-0.75)'
and M1 to M1
'zpk([-0.089+8.28i,-0.089-8.28i,-0.113+19.058i,-0.113-19.058i],[-0.03+21.271i,-0.03-21.271i,-0.076+14.435i,-0.076-14.435i,-0.044+6.384i,-0.044-6.384i],71.17)'
I have uploaded the correct ones to the HLTS/Common/FilterDesign/Estimator with today's date (2025-04-23), svn revision 12279.
That filter change has been loaded in
