Design and simulation of an autonomous underwater vehicle

The Mechatronics and Dynamic Modelling Lab of the University of Florence (MDM Lab) is developing an AUV (Autonomous Underwater Vehicle), called "Tifone", for the monitoring of underwater archaeological sites. This research is a part of the Thesaurus project, funded by Regione Toscana. The vehicle is designed in order to carry out a customizable payload according to different mission profiles. The main technical requirements of the vehicle are a maximum operative depth of 300 m, a maximum speed of 5 knots and an autonomy of more than 8 hours; a torpedo-like design allows to achieve benefits from a fluidodynamic point of view. A high manoeuvrability and hovering capacities are required to perform complex explorations and monitoring tasks: that is why a motion control based on lateral and vertical thrusters has been preferred with respect to the typical use of control surfaces, also in order to have a more reliable system as concerns component failures. The control system has to ensure a good trade-off between manoeuvrability and stability at cruise speed, too. The paper focuses on two different control strategies, corresponding to the different mission profiles the vehicle is able to perform.