[Ushiba, Takahashi]
We went to the health check of the MCi suspension.
I remeasured MCI mechanical transfer functions after fixing MCI.
Figure 1 to 3 show the TFs from Euler DoFs (L, P, and Y).
Figure 4 to 7 show the TF from Coil DoFs (H1, H2, H3, and H4).
Followings are what I noticed when checking TFs:
1. Coupling from L to angular motions increased, especially L2Y.
2. DC gain of P2P TF increases a little while high frequency seems the same, which implies resonant frequency is slightly shifted to low frequency.
3. P2Y coupling increases a lot.
4. H1 and H3 TF measurement have low coherence around 4 Hz and more. Does this imply that MCI suspension rubbing somewhere?
In the morning meeting, I said TF gain of yaw changes a lot but it is not ture (I misunderstood yaw TF and P2Y coupling).
I measured TFs of MCI again for health check after fixing the EQ stops of MCI (klog28379).
The low coherence around 4 Hz in H1 and H3 coil TF measurement was disappeared and they looks healthy.
I measured TFs of MCI after installation of new side stopper (it will be posted later, hopefully).
Figure 1 to 7 show the result.
All TFs seem healthy but have low coherence at low frequencies.
One possible reason is air flow due to the aluminum cover, which just closed MCF flange before but is an aluminum tube to connect MCF to MCE now.
Anyway, suspension TFs themselves seem fine, so we can proceed the closure process.
Result of final health check of MCI.
All TFs seem healthy.
