Over the past few days I optimized the damping filters for the HTTS suspensions (RMs, OMs) and the OMC SUS.  For the most part this was an exercise of copying the filters from L1 and making sure the gains were sensible.  (For the HTTS, I used the filters that Rana had set up at L1.)  I've changed the damping gains and filter settings for the DAMP loops on the following suspensions: RM1, RM2, OM1, OM2, OM3, and OMCS.  We should update the safe.snap files on Monday.

For each optic and each damping loop I set the gains using the impulse response to judge the Q of the fundamental modes.  The first image attached shows the OM1 response in L, P, and Y to impulses.  The Q in each case is about 5.  (I applied the impulses using the LOCK filter banks, and thanks to Koji's diagonlization of the LOCK inputs to the OMs there is very little DC coupling between the DOFs.)

The second plot is damped spectra for the OMs, compared to the damped spectra before I changed the filters.  The OMs were somewhat overdamped before the changes.

For some reason the RM1 damping loops are different by a sign from the other HTTS, I'm not sure where this sign flip is coming from.  For RM1 the damping gain is 1.0, for all the other HTTS it's -1.0.  The gains that are hard-coded into the 'gain' filter in each L,P,Y filter bank are the same for each optic.

Once I finished with the HTTS suspensions I worked on the OMC.  H1's OMCS hadn't been damped before; I tried to do some clever filter work but in the end I found the imported filters from L1 worked well (a zero at 0Hz, two poles at 30Hz, and a 4th-order elliptic rolloff at 50Hz.)  The one difference is the YAW loop, I added a boost filter at 0.54Hz.  The third plot attached shows the damped and undamped spectra of the OMCS in the six degrees of freedom.  The gains for each DAMP filter bank were set using the impulse response.  They are:

I also went through the OSEMINF filter banks for each optic and made sure each had a comb(60,30,-50,4).