LIGO Document T1800077-v4

Optimal control of the ARM alignment with digital compensation of the Sidles-Sigg radiation torque

Document #:
Document type:
T - Technical notes
Other Versions:
We apply the optimal control techniques (H-infinity and mu-syntheses) to align the aLIGO arm cavity. For the soft mode, it can be further combined with the digital subtraction of the Sidles-Sigg torque so only one set of filters is needed for different input power levels.

We show that our scheme can simultaneously improve the low-frequency rms motion and the high-frequency sensing noise. Moreover, the controller is robust under typical fluctuations in the arm power and/or sensing gain.

Files in Document:
Other Files:
Associated with Events:
GWADW 2018 held from 12 May 2018 to 17 May 2018

DCC Version 3.4.1, contact Document Database Administrators