The VST telescope optomechatronic control system

The VST (VLT Survey Telescope) is a 2.6m optical ground-based telescope to be installed in the Cerro Paranal (Chile) observational station of the European Southern Observatory (ESO). It is a joint project of INAF-Osservatorio Astronomico di Capodimonte, responsible of the telescope design and realization, and ESO, responsible for the civil infrastructures and the daily operation of the instrument. The control system of the telescope is by definition an opto-mechatronic system. It combines mechatronic and optical disciplines together with the final aim to produce sharp images of star objects. Feedback control systems are partially based on mechatronic conventional sensors like position transducers, but also optical feedbacks coming from two separate technical CCD sensors are used to implement outer control loops for the compensation of optical aberrations e.g. introduced by the gravity, by shape imperfections or flexures in the mirrors, by thermal effects, by a not perfect alignment of the telescope axes.}