The Real-time Distributed Control of the Virgo Interferometric Detector of Gravitational Waves

The VIRGO experiment for the detection of gravitational waves is a big challenge both for physics and for technology, in particular, to satisfy the stringent requirements on the alignment and position of its suspended optical components to keep the detector at its working point, a very complex distributed and supervised control system has been implemented. The current constraints are about 10^-10 m RMS for the longitudinal control ( "Locking" ) and 10^-9 rad RMS for the angular degrees of freedom ( " Alignment " ). These requirements are satisfied by means of a specially designed hierarchical architecture for the local control system, necessary for managing the hard task of filtering all the environments noises that limit the sensitivity of the interferometer, supervised by a distributed global control system to maintain the detector fully operational. In this paper we described the status of the real - time distributed control system of the Virgo interferometric detector of Gravitational waves, its performances and planned improvements.