Agenda/Minutes of the VIS Meeting on 2019/6/28

2019/6/21 13:00 - 15:20

Zoom Meeting

Participants: Mark, Takahashi, Hirata, Shoda, Terrence, Akutsu, Fabian, Enomoto, Okutomi, Fujii, Sato, Tanaka

BS baffle review

• slides

• The design seems OK

Progress report

Type-A (Takahashi)

Past week report

[Okutomi]

• Monitored the drift of the IP and GAS displacements of the ETMY during the air injection.
• Tried to offload the DC output to the F3 GAS actuator with the FR, but it resulted that the stepper motor seems stuck.
• The ETMY chamber is in air pressure.

Plan for coming weeks

• CRY team will recover the problem of the ETMY payload in 28-30th.

Type B (Mark)

Report for the week 6/24 (Written by Terrence and Fabian)

• Type B watchdog/DACKILL is split for tower and payload. Now, tripping the payload watchdog will only trigger the payload DACKILL while tripping the tower watchdog will trigger both watchdogs and DACKILL. The MEDM screen is updated to accommodate the changes. The screen is also modified so the reset buttons for watchdogs and DACKILL are all available on the same screen. In the middle of this work, a bug is discovered in the ModerateWD.c where setting 0 to the ramp down time would cause the WD to loop in an endless ramp down cycle.
• The Guardian is updated to recognize if the payload is tripped and decide which tripped state it should go to, "TRIPPED" or "PAYLOAD_TRIPPED". So, if both tower and payload controls are on while the payload watchdog tripped, the guardian will jump to the "PAYLOAD_TRIPPED" state and shutdown payload controls only. When the WD and DACKILL are reset, the "TRIPPED" state will dump you out to the safe state where all controls are disengaged, while the "PAYLOAD_TRIPPED" state will dump you out to the "ENGAGING_IM_DAMPING" state where the tower controls are still on.
• VIS monitor is updated. It will monitor the raw sensor input and actuator output and check if they are within the operation range. The indicator will turn orange when it is 50% out of range and will turn red if it is 90% out of range. The indicator for actuators will turn blue if they are not in use. The limits of the operating range can be set in userapps/vis/k1/guardian/VIS_DICT.py. The range for OL_PIT and OL_YAW are default to be [-1,1], the lower limit of the OL_SUMs are default to be 1000 counts while those for the other are default to be [-32768,32768].

• If you know the range of certain sensors and actuators, you are strongly encouraged to tweak the thresholds in the file. Otherwise, the function of the monitor will be very limited.

• Fabian checked again the GAS filter control noise:
  • My previous calculation considered damping filters and those injected too much noise in the observation frequency band. Rolling the filters off with (high order) Butterworth filters rendered the system unstable.
  • I then considered DC control filters only and I was able reduce the injectetd noise to acceptable levels while keeping the loop stable. As pointed out by Shoda-san, this was the strategy devised for the Type B prototype.
  • This has only been tested in software, not in the actual system. I aim to do implement it next week.
  • This strategy will work only if the resonant motion of the system is not excited after disabling the payload and GAS chain damping control. On the 23rd of May Terrence measured the residual motion with the control system (including IP) on and off. There was no subtantial difference between the two. I aim to take more measurements.
• Terrence and Fabian are currently going through the oplev diagonalization procedure and will write down the procedure.
• Hirata-san worked in the design of the baffles for the BS.

Plan for the week 7/1

• Terrence and Fabian will continue writing the oplev diagonalization procedure.
• Fabian will install the rolled-off the DC control filters.

Type-Bp (Shoda)

Past week report

• Auto-offload for GAS script is available from medm.
• Summarizing information in wiki page.
• Checking PR3 and PRM Traverser drivers
  • Actually PR3 driver is healthy according to Enomoto-kun, but R2 motor connection is found to be dead last week.
  • For PRM driver, PLC is working at least. We need 5-phase motors for the test. (I have only 2-phase one now.)
    • PRM Traverser driver was dead once but it was fixed by Uraguchi-san. But I heard Enomoto-kun and Miyo-kun found that it was not working recently.

Plan for coming weeks

OMMT & OSTM (Takahashi)

Past week report

• Modification parts are under manufacturing.
• Making the overall 3D model around OMC.

Plan for coming weeks

• Considering the delivery time of OSTM itself, the installation work at the site will be available in September.

• Schedule was updated (PDF/MPP).

VIS electronics (Tanaka)

Past week report

Plan for coming weeks

Other site works

Safety

• Incidents: no incident
• Foreseen risks
  • Type-A:
  • Type-B:

Discussion

PRM removal

• Schedule
  • Preparation: 2 days
  • Unhook the optical bench: 1 day
  • Remove the suspension: 1 day
  • Remove the IM for the optical bench: 1day
  • Total 1.5 weeks ?
• Necessary items/preparation
  • Assembly frame: sitting next to PRM
  • Clean up the work space
  • Clean cover
  • Jacks
  • Small tools
  • Big Allen keys
• How to keep the cleanliness during storage
  • Apply first contact to the mirror
    • Need to decide who will do this
  • Cover the entire suspension with the clean bag
  • Then wrap the entire system with cling wrap
• Other notes
  • When disconnecting in-vac cables, put labels so that the re-connection work is easy

SRM mirror exchange

• Change the mirror from 70% to 0% reflectivity
• The SRM-W (R=0%) must be stored somewhere near SRM
• It is in a holder but the spacer thickness may be non-optimal
• We need to make sure that the wedge direction is correct.
  • The current wedge direction is the opposite of the original design

Travel Plans

• Travel (Week of 7/1):
  • Takahashi: 1-2
  • Sato:
  • Hirata:
  • Shoda:
  • Fujii: 1-3
  • Tanaka:
  • Terrence:
• Travel (Week of 7/8):
  • Takahashi:
  • Sato:
  • Hirata:
  • Shoda:
  • Fujii: Amaldi
  • Tanaka:
  • Terrence:

Next meeting

On 2019/7/5(Fri)