In this paper the architecture developed for the automatic tuning of the control loops of Unmanned Aerial Vehicles is presented. In order to validate this architecture, the VOLCAN UAV has been used as test platform. The simplified control system of the VOLCAN UAV, based on cascade controls of PIDs, is introduced, together with the automatic procedure that has been implemented. A Human Machine Interface allows the rapid automatic tuning of the system by means of Åström and Hägglund's method. Finally, the Hardware in the Loop architecture used to test both the control algorithms and the tuning procedure is presented.