jeffrey.garcia@LIGO.ORG - posted 19:56, Wednesday 09 November 2011 - last comment - 14:28, Thursday 10 November 2011(1691)
H2 FMY M1 Transfer Functions
The attached plots are the results of open-loop transfer function measurements for the M1 stage of H2 FMY. The measurements are open-loop from the "H2:SUS-FMY_M1_TEST_*DOF*_EXC" channels to the "H2:SUS-FMY_M1_DAMP_*DOF*_IN1_DQ" channels. Results agree quite nicely with the model. There might be a lower signal-to-noise ration for the really low frequencies (See "L","P",Y" below 0.5Hz), so further measurements with higher drive amplitude in this band might be desirable. Scripts, data, and plots are in the SUS SVN. Excitation and Data retrieval script:'~/SusSVN/sus/trunk/BSFM/H2/FMY/SAGM1/Scripts/collect_TF_H2FMY_M1_allDoFs_0p05to50Hz.m'Data .mat file:'~/SusSVN/sus/trunk/BSFM/H2/FMY/SAGM1/Data/111108_H2FMY_0p01to50hz_all_DoFs_5Kcts_highres.mat'Plotting script:'~/SusSVN/sus/trunk/BSFM/Common/MatlabTools/plotBSFM_matlabtfs.m'Plots (individual and combined):'~/SusSVN/sus/trunk/BSFM/H2/FMY/SAGM1/Results/'
Non-image files attached to this report
Comments related to this report
Here's the remaining degrees of freedom, and I've fixed a big in the x ticks, such that they're on powers of 10 (instead of 0.5, 5, 50, etc). Initial investigation comments: We don't understand the blip at 0.65 Hz in Longitudinal. It doesn't appear in any other degree of freedom, and especially not in the likely suspect of Pitch. (Though there is some evidence for excess coupling in the L to P transfer function -- see page 10). The higher Vert, Trans, and Roll modes are lower in frequency than the model. Not really a point for concern just yet, we'll need to compare against (i.e. put on the same plot) the 110823 measuremnt (in progress). The lowest modes in the Pitch TF are not as "Q"-ey as we've seen. The highest Yaw mode is also not as "Q"-ey as has been seen. My guess is there's something rubbing, 'causing the reduced Q's of the P and Y modes, and also cause the weird blip in L. More analysis to come!!
Non-image files attached to this comment
Also, I've commited and updated the changes toplotBSFM_matlabtfs.mthat merge all plots produced, and fixed the axes bugs. Update to rev 1548