A state observer for the Virgo inverted pendulum

T. Accadia, F. Acernese, P. Astone, G. Ballardin, F. Barone, M. Barsuglia, A. Basti, T.S. Bauer, M. Bebronne, M.G. Beker, A. Belletoile, M. Bitossi, M.A. Bizouard, M. Blom, F. Bondu, L. Bonelli, R. Bonnand, V. Boschi*, L. Bosi, B. BouhouS. Braccini, C. Bradaschia, M. Branchesi, T. Briant, A. Brillet, V. Brisson, T. Bulik, H.J. Bulten, D. Buskulic, C. Buy, G. Cagnoli, E. Calloni, B. Canuel, F. Carbognani, F. Cavalier, R. Cavalieri, G. Cella, E. Cesarini, O. Chaibi, E. Chassande-Mottin, A. Chincarini, A. Chiummo, F. Cleva, E. Coccia, P.F. Cohadon, C.N. Colacino, J. Colas, A. Colla, M. Colombini, A. Conte, J.F.J. van den Brand

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


We report an application of Kalman filtering to the inverted pendulum (IP) of the Virgo gravitational wave interferometer. Using subspace method system identification techniques, we calculated a linear mechanical model of Virgo IP from experimental transfer functions. We then developed a Kalman filter, based on the obtained state space representation, that estimates from open loop time domain data, the state variables of the system. This allows the observation (and eventually control) of every resonance mode of the IP mechanical structure independently. (C) 2011 American Institute of Physics. [doi:10.1063/1.3637466]
Original languageEnglish
Article number094502
Number of pages9
JournalReview of Scientific Instruments
Issue number9
Publication statusPublished - 1 Sept 2011
Externally publishedYes


  • gravitational wave detectors
  • interferometers
  • Kalman filters
  • nonlinear systems
  • pendulums

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