I updated the reference plots to the recent healthy ones (2024/03/22, after oplev centering, klog28942 ).

The PIT resonance frequecy around 3.5 Hz seems to shift lower, and DC gain slightly increased. The others seem to fine (H2 and H4 measurements seem to be performed at a noisy timing?)

With Ohshino-san, Ushiba-san

The latast measurements look healthly.

The difference from the reference data and the reason we think.
At first, we checked the actuator gain (COILOUTF gain) for each coil. The values changed from the reference measurement time.
We think this caused the difference we found.

• L->Y:
  • Because of the diagonalization after the reference measurement time, 2Hz peak which is the Y resonance went lower.
  • The low frequency region diff should be also caused by this.
• P->P
  • The overall gain change should be caused by the COILOUTF gain change.
• P->Y
  • The latest measurement result is much lower than the ref, which means the diagonalization works well.
• H1->P, H1->P, H4->P
  • These diff are also caused by the COILOUTF gain changes

With Oshino-san

We performed the off-load work for MCE.

Procedure

1. Request `SAFE` to the suspension guardian.
2. Monitor oplev signal P, Y, Sum
3. Turn On pico of MCE
4. Change the pico to make P, Y to be around 0.
5. Remove offset value during the control
   1. `OPTICALIGN` and `ISCINF` need to be managed.
   2. Remove "offset" of `OPTICALIGN`
   3. Check ASC signal and remove the offset: MEDM -> IMC -> ASC
      1. Check the output matrix of P and Y to see which signal is sent to the suspension.
      2. At this case, DOF_1 is the signal
      3. Open the filter window and click `CLEAR HISTORY`

After this work, we requested LOCK_AQUISITION to check. It works.
Then, we kicked health check script.