After the large earthquake at 12:26 JST, IFO becomes unstable.
After several investigation,it seems that PR3 yaw motion after it moves to LOW_NOISE state.
Figure 1 shows the guardian state number and PR3 yaw signals.
PR3 yaw motion becomes large after PR3 reaches LOW_NOISE state.
In the LOW_NOISE state, filters to reduce te gain of BF control and IMY controls are engaged.
So if we skip the engagement of these gain reduction filters for YAW controls, the stability would be recovered.
Since this modification changes the SDFs, I wil negotiate with Miyoki-san and Miyakawa-san according to the SDF management procedure.
