Unify the IP-L/T loops for all four suspensions

[YoshinoriFujii]

Background

• ITMY-IPがうるさい -> the difference from the others are:

  • the shape of the IP-L/T filter

• For getting close to the ideal goal: realizing same 4 suspension, it would be better to use same shape filters.

• The monitored spectra are:

  • Assuming this plot is true, only ITMY is oscillating larger than the other suspensions in L, at TM-stage
  • Anyway ETMX-BF-Y sensor much couples to BF-L motion, this is to be diagonalized.
  • [ ] open new issue for this.

[YoshinoriFujii]

2019.10.4

• The currently implemented one:
  • IP-L
  • IP-T

• red: ITMY-IP-L
• blue: ITMY-IP-T

• green: ETMX-IP-L

  • IP-Y

  -red: ITMY-IP-Y

• blue: ETMX-IP-Y

[YoshinoriFujii]

modification plan

Filter bank information

---

• IP-L, The following was removed:
  • FM3: zpk([],[0.001],1,"n")gain(600)
  • name:dc

  • blue: Before
  • red: After

---

• IP-T, The following was removed:

  • FM3: zpk([0.07],[0.001],1,"n")gain(600)

  • name:dc

  • blue: Before

  • red: After

---

• IP-Y, The following was removed:
  • FM4: zpk([0.3;0.3],[3;3],1,"n")butter("LowPass",4,2.5)gain(10000)
  • dame: damp2

- blue: Before
- red: After