Vibration Isolation GroupVibration Isolation Group

R. Takahashi (ICRR)R. Takahashi (ICRR) ChiefChiefT. Uchiyama (ICRR)T. Uchiyama (ICRR) Payload designPayload designH. Ishizaki (NAOJ)H. Ishizaki (NAOJ) Prototype test Prototype test R. DeSalvo (Caltech)R. DeSalvo (Caltech) SAS designSAS designA. Takamori (ERI)A. Takamori (ERI) SAS designSAS designE. Majorana (INFN)*E. Majorana (INFN)* Payload modelingPayload modelingT. Sekiguchi (ICRR)T. Sekiguchi (ICRR) System System modelingmodeling

* unofficial member

LCGTA-review of VIS(29 Nov., 2010)

R&DR&D

TAMA-SAS in TAMA2005-2009

One-leg IP in Kamioka2009-2010

Payload and

GASF prototype in NAOJ

2011

Disposition of vibration Disposition of vibration isolation systemisolation system

Vacuum chamberA) φ2m × (2.5m + 2.45m cryostat)B) φ2m × 4.3mC) φ2m × 3m

Vibration Isolation SystemA) IP + GASF (3→ 4 stage) + Payload (cryogenic)B) IP + GASF (2 stage) + Payload (room temp.)C) STACK + Double-pendulum

ConfiguratioConfigurationn

iLCGT bLCGT

ITMX, ITMY, ETMX, ETMY

Type-A IP-GASF + Type-B Payload(25cm, 10kg)

Type-A IP-GASF + Type-A Payload(25cm, 30kg)

BS, PRM, PR2, PR3, SRM, SR2, SR3

Stack + Type-B Payload(25cm, 10kg)

Type-B IP-GASF + Type-B Payload(25cm, 10kg)

MC2F, MC2E, PD Type-C(10cm, 1kg)

Type-C(10cm, 1kg)

ConfigurationConfiguration

Type-A(old)

Support structure of SAS tower is too weak.

Type-B

Type-C

Filter0 Filter1 Filter2 PF IM-MB TM-RM

Sensor ACC(H) x3ACC(V) x1LVDT(H) x3LVDT(V) x1

LVDT(V) x1

LVDT(V) x1OL x1

PS(H) x3PS(V) x3OL x1

PS(H) x3PS(V) x3

PS(H) x1PS(V) x1OL x1

Actuator

MC(H) x3MC(V) x1

MC(Y) x1 MC(H) x3MC(V) x3

MC(H) x3MC(V) x3

MC(H) x2MC(V) x2

Motor STEP(H) x3STEP(V) x1

PICO(Y) x1

STEP(H) x2STEP(V) x2

ACC: accelerometer, LVDT: linear variable differential transformer PS: position sensor, OL: optical lever, MC: magnet-coil, STEP: stepping motor, PICO: picomotor

For cryogenicStepping motor: tested in Rome, 4.8K ok!Position sensor: shadow sensor → fiber sensorActuator: design taking account of eddy current problem

Sensor and actuator

Point Mass Model by R. Takahashi

m Q f0 C[kg] [Hz] [kg・Hz]

Filter0 120 1 0.07 -Filter1 120 100 0.56 -Filter2 120 100 0.56PF 120 100 0.5 -IM 60 1000 0.7 530MB 60 1000 0.7 530TM 30 1000 0.8 -RM 30 6 0.8 -

xg

x1

x2

x3

x5 x4

x0 m0

m1

m2

m3

m5

m6

m4

m7

C

x6 x7

Filter0

Filter1

Filter2

PF

IM

TM RM

MB

Equation of motion of 8 material points model

8 ｘ 8 stiffness matrix Refer parameters of TAMA-SAS Calculated by MATLAB

Type-A (old)

m Q f0 C[kg] [Hz] [kg・Hz]

Filter0 60 1 0.07 -Filter1 60 100 0.34 -Filter2 60 100 0.34 -Filter3 60 100 0.34 -CB 60 100 0.35 376PF 60 100 0.5 376IM 60 1000 0.7 530MB 60 1000 0.7 530TM 30 1000 0.8 -RM 30 6 0.8 -

xg

x1

x2

x3

x5 x4

x0 m0

m1

m2

m3

m5

m6

m4

m7

C

x6 x7

Filter0

Filter1

Filter2

PF

IM

TM RM

MB

Equation of motion of 9 material points model

10 ｘ 10 stiffness matrix 2-layer structure Calculated by MATLAB

Type-A (new)

Filter3+ CB

m Q f0 C[kg] [Hz] [kg・Hz]

Filter0 40 1 0.07 -Filter1 40 100 0.56 -PF 40 100 0.5 -IM 20 1000 0.7 177MB 20 1000 0.7 177TM 10 1000 0.8 -RM 10 6 0.8 -

xg

x1

x2

x3

x5 x4

x0 m0

m1

m2

m3

m5

m6

m4

m7

C

x6 x7

Filter0

Filter1

Filter2

PF

IM

TM RM

MB

Equation of motion of 7 material points model

7 ｘ 7 stiffness matrix 10kg LIGO mirror Calculated by MATLAB

Type-B

m Q f0 C[kg] [Hz] [kg・Hz]

Stage0 200 3 5 -Stage1 200 3 4.5 -Stage2 200 3 4 -IM 1 1000 1 12.5MB 1 1000 3 12.5TM 1 1000 1 -

Equation of motion of 6 material points model

6 ｘ 6 stiffness matrix Model for Stack is simplified Calculated by MATLAB

Type-C xg

x1

x2

x4 x3

x0 m0

m1

m2

m4

m5

m3

C

x5

Stage0

Stage1

Stage2

IM

TM

MB

Displacement of test massThe horizontal isolation >3Hz is due to a heat link of 0.03Hz.The vertical isolation is better than the horizontal isolation around 1Hz because of 4 stage GAS filters.Since the final stage (TM) is suspended by 4 sapphire fibers of φ1.8mm, the vertical resonant frequency is about 100Hz.Heat links of 0.03Hz with 1% coupling from vertical mode satisfy demands at 10Hz.

Displacement of each systemThe isolation of Type-B is better than the isolation of Type-A with heat links >4Hz.When the part of IP-GASF of Type-B is fixed (iLCGT), the isolation of Type-A is worse than the isolation of Type-C with stack >20Hz.

RMS

Type-A,B vs. C0.1 → 2 [m] x200.1 → 2 [m/s] x20

Integration 0.01-4Hz(Integration 0.1-4Hz)

SimMechanics (The MathWorksTM)Based on multi body dynamicsI) If geometric/topological parameters are determined,

equations of motion/transfer functions are obtained almost automatically.

II) Direct integration into the Simulink environment.III) How it is calculated is in a black box.

Rigid Body Model by T. Sekiguchi

Test Simulation (2D SUS)Triple pendulum suspension system with y, yaw and roll suppressed.Calculated transfer functions (X-X, X-Pitch, X-Z) without geometric asymmetry

The parameters (mass, wire length, etc) may be changed easily.Geometric asymmetry may be taken into account. (Now Constructing)

OctopusOctopus is a non-official Virgo tool. The modeling will be used for AdV,

but it is not the only model that can be used. It provides (once completed):

I) Point-by-point 6x6 matrixes of Force/displacement TFs or displacement ratios.

II) Designing tool: several configurations or parameter tuning, within a given configuration can be explored.

III) Some add-ons as fitting a dataset of experimental TF and extracting a fit which can be used to extract actual mechanical parameters (…).

Rigid Body Model by E. Majorana

This presentation/practical cases.- Often it is useful to show longitudinal/pitch and transversal/yaw sub-matrixes - In the case of LCGT, the Vertical might be more crucial and should be included.

Example of outputs of OctopusX Y Z Tx Ty Tz

Fx

Fy

Fz

Ftx

Fty

Ftz

ScheduleSchedule

Procedure of installation for ITM/ETM

1. Set IP/GASF （ Tower ）2. Connection of Dummy mass (200kg+100kg)3. Embed accelerometers (geophones) 4. Wiring 5. Release Tower6. Control test (diagonization) 2 month for 2

sets7. Fix Tower8. Dismount Dummy mass (100kg)9. Connection of Payload 10. Wiring 11. Release Payload12. Control test 1 month for 2

sets13. Release Tower / Fix Dummy mass (200kg)