Accadia, TAcernese, FAntonucci, FAstone, PBallardin, GBarone, FBarsuglia, MBasti, ABauer, T.S.Beker, M GRabeling, David2015-12-102015-12-100927-6505http://hdl.handle.net/1885/61980In this paper the performances of the Automatic Alignment sensing and control system in the Virgo gravitational wave detector, during the second scientific run from July 7th 2009 to January 8th 2010, are described. The accuracy of the angular control loops fulfills the original Virgo requirements, reaching the accuracy of a few nano-radians for the most critical angular degrees of freedom, and the control noise is below the Virgo design sensitivity in the whole detection band.Keywords: Angular control; Automatic alignment; Degrees of freedom; Design sensitivity; Gravitational wave detectors; Sensing and control system; Control theory; Detectors; Gravitational effects; Gravity waves; Interferometry; Remote control; Alignment Alignment; Angular control; Control systems; Gravitational wave detectors; Interferometry201110.1016/j.astropartphys.2010.10.0052016-02-24