A new prototype of Unmanned Surface Vehicles to survey the coastal marine environment: design, modelling and control

Riassunto

In the recent years, Unmanned Surface Vehicles (USVs) have proved their usefulness in particular to collect data for marine research and environmental survey. The use of these controlled remotely platforms, without direct human control, have improved the capacity to image, and monitor the seabed and the costalmarine environment. Outfitted with different instruments (payload), the USVs are used for marine, river and lake activities, such as environmental monitoring, water quality sampling, hydrologic survey, target tracking and scientific survey [Bertram, 2008; Manley, 2008; Giordano et al., 2015]. Other fields of application include harbor surveillance, maritime search, rescue and natural disaster damage assessment [Steimle et al., 2009]. One of the first USV was ARTEMIS, designed in 1993 at MIT (Massachusetts Institute of Technology, Sea Grant Collage) [Manley, 1997] to collect bathymetric data and it was characterized by a propulsion system with two electric motors and a rudder servant-implemented. The USV was equipped by an automatic control of the heading and an autonomous navigation capacity through reference points (waypoints). Its small dimension (about 1.37m long) was the main shortcoming, limiting the endurance and the sea keeping. Following the development of ARTEMIS, to improve the transverse stability and to design more payload capacity and redundancy as regards the buoyancy, MIT adapted the catamaran shape for the hull and removed the rudder; the steering is based on a differential propeller revolution rate. After the MIT, several USVs were designed within many research projects. Among these, other USV were realized. The DELFIM, capable of working in close cooperation with an Autonomous Underwater Vehicles (AUV) [Pascoal et al., 2000] and the ROAZ, ROAZ II, that, set up for bathymetry survey, were designed to allow testing and validation of new developments in monitoring, coordinating multi-vehicle navigation, sampling and other research topics related to marine surface vehicles [Ferreira et al., 2006a, 2009]. Further developed concerned the SWORDFISH, MESSIN and SPRINGER...