ANALYSIS, DESIGN AND PROTOTYPING OF AN INNOVATIVE HIGH-SPEED MARINE VEHICLE

This thesis concerns the development, prototyping and design of a new concept of a high speed sea drone. The basis of this invention is the fact that it was introduced a smart suspension system that can somehow alleviate the stresses caused by wave action and improve the sea keeping at high speed in rough seas. The High Speed Marine Vehicle (HSMV) designed in this work is therefore able to surf on the waves by means of planing skid with an active trim control, connected to the hull through a sophisticated suspension system composed by semi-active elements, innovative architectures and associated new control logic in order to achieve a desired attitude of high speed vehicle while mitigating the impacts of the shocks produced by the water re-entry. We have analyzed some important analytical aspects concerning an innovative new style of navigation called "wave jumping" and, thanks to the development of a simulator, it has been possible to verify and test the dynamic behavior of the drone. A strong emphasis has been given to the development of innovative suspension architectures that, through appropriate control strategies developed in this thesis, was able to obtain good results with regard to maintaining the trim and achieving high speed (150 km/h) in the presence of wind of about 20 knots. In this work have been introduced new control logics based on the calculus of variations and direct control of the energy that better exploit the innovative suspension architectures, patent protected, based on semi-active systems suitable to change not only the damping, but also the stiffness of the system through use of two or more variable dampers.