ITMY is now oscillating a lot maybe in yaw at the level of 5urad at around 1 Hz.
This started from the last night gradually.
The damping control gain reduction might be necessary.
To supress ITMY oscillation, I turned on ITMY_NBDAMP_Y3 loop.
After turning on the filter, ITMY seems to be calm down.
I also engaged NBDAMP_Y4 loop to reduce the oscillation at 2.21 Hz.
I checked the spectram with switch ON/OFF the NBDAMP Y2 and Y3.
These Y2 and Y3 made noise around 1.1Hz and 2.5Hz at the LOCK_ACQUISITION state.
And there was not peaks even without Y2 and Y3 at the LOCK_ACQUISITION state.
So probably, we don't need there filters?
I turned OFF these filters.
(Work on 1/8)
We found that these oscillations grow over the course of several hours, so we turned on these two control loops (Y3, Y4).
Additionally, we modified the Guardian to enable turning them ON/OFF.
