Reports 1-1 of 1 Clear search Modify search
VIS (IY)
koki.okutomi - 19:40 Wednesday 31 July 2019 (9732) Print this report
ITMY motor inspections

* (Work log on July 30 and 31)

[Okutomi, Fujii, Sato]

TL;DR

  • F0 yaw motor ---> became available
  • Stepper motors of IP H1, H2, H3, and F0 yaw: calibrated
  • IP and BF LVDT polarities: confirmed
  • BF LVDT vertical positions: slightly improved
  • Cable tensions below the BF: slightly relaxed
  • BF yaw picomotor: quickly inspected but still not working
  • ITMY tower current status: IP and BF are mechanically fixed

What we did

  • We found that the F0 yaw motor was actually stuck.
    • This malfunction was resolved by rotating the bellows by hand so that it has the nominal expansion.
      • cf. JGW-D1809225: Yaw stepper motor drive unit for Type-A and Type-B TF
      • https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=9225
    • Now the motor driving became available again.
    • We added a threaded PEEK part to the motor unit of the ITMY to reduce the friction in the motor driving.
  • We calibrated the accessible motors around the IP.
    • The calibration results will be posted soon.
    • It seems that the IP stepper motors have limit detectors at both ends of the slider. (Shamefully enough, WE DID'NT KNOW THAT!!)
    • The limit flag is not utilized yet. We need to analize the stepper motor driver to implement the limit detection.
  • The polarities of the LVDT on the IP and BF were confirmed.
    • We found that the existing signs in LVDTINF are correct.
  • The vertical positions of the BF LVDT secondary coils were adjusted.
    • Due to the height adjustment of the ITMs in May, the primary coils (suspension side) were close to the upper end of the movable range.
    • But the situation was not much improved because most of the secondary coils (frame side) were already set at the highest position.
    • We'll confirm the narrowest gap between them after the TM OpLev alignment.
  • The tension of the cables just below the BF was slightly relaxed by re-tying them with a PEEK tie.
  • We inspected the BF yaw picomotor visually with a fiber scope.
    • The motor shaft looked not rotating with the driving inputs even when the sound of motor driving could be heard clearly.
    • We could not localize the cause of malfunction yet.
      • But we suspect there's some mechanical problem in the motor since we could not find any problem in the electric part so far.
    • We stoped here today. For further inspection, we need to open the cup of the BF which takes much time.

Next step

  • Releasing IP and BF and their DC position adjustment for TM OpLev alignment
  • Health check of the suspension by measuring transfer functions
Comments to this report:
yoshinori.fujii - 20:37 Wednesday 31 July 2019 (9734) Print this report

Supplementary notes for VIS folks:

  • > Stepper motors of IP H1, H2, H3, and F0 yaw: calibrated
    • The details of the calibration curves are posted soon.
    • The results are stored here.
  • > IP and BF LVDT polarities: confirmed
    • All of them were consistent with the design. No mistakes were found in the sensor polarities.
  • > Cable tensions below the BF: slightly relaxed
    • We wanted to relax it since we were doubting this is the one of the reason of the issue in klog#9172. This is t be checked with transfer function measurement.
  • > BF yaw picomotor: quickly inspected but still not working
    • We sent steps to the pico-driver and saw if the motor works with a fiber-scope. Then it seemed that the motor did not work, even though the sound was there.
  • > ITMY tower current status: IP and BF are mechanically fixed
    • After the payload was released, the tower-part releasing buisiness is to be started.

 

  • The photos are stored here.
  • For a TEMPORARY use, I have prepared a dir for the health check measurement files (only for IP-L/T/Y, BF-L/T/Y):
    • /users/VISsvn/TypeAtower/ITMY/Measurements/TF/template/
    • /users/VISsvn/TypeAtower/ITMY/Measurements/TF/reference/
    • Please start from them and PLEASE DO NOT SET LARGE AMPLITUDE. The default amplitude are roughly tuned but it is roughly.
Search Help
×

Warning

×