Efficient motion planning of multiple unmanned surface vehicles (USVs) in a dynamic maritime environment is an important requirement for increasing mission efficiency and achieving motion goals. The current study integrates two approaches of intelligent path planning and virtual target path following guidance for multi-agent USV framework to perform a coordinated and cooperative navigation of USVs in a constrained maritime environment. In the current study, a safety distance constrained A* approach produces an optimal, computationally efficient and collision free path which is later smoothed using a spline to provide an optimal trajectory as input for virtual target based multi-agent guidance framework to navigate multiple USVs. The virtual target approach provides a robust methodology of global and local collision avoidance based on known positions of vehicles. The combined approach is evaluated with the different number of USVs and in different environmental scenarios to understand the effectiveness of approach from the perspective of practicality, safety and robustness. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

This paper describes U-SWATH an innovative Unmanned Surface Vehicle (USV), based on a Small Waterplane Area Twin Hulls (SWATH) design, developed by CNR INSEAN and ISSIA for institutional research purposes. The vehicles is composed of a wide flat deck covered with solar panels which connects two torpedo hulls. The hulls are composed of modular and interchangeable sections that can be outfitted with different payloads, equipments, propulsive or manoeuvring elements. The propulsion system is based on ad hoc electrical azimuthal thrusters. The solar panels covering the wide U-SWATH bridge are used for recharging the batteries supplying power to the vehicle. U-SWATH is multitasking and the goal of the designers was to develop a cutting-edge autonomous multi-purpose platform for carrying out research in the marine and the maritime fields.

This technical report describes an innovative and integrated prototype system of Unmanned Surface Vehicles (USVs) for advanced environmental monitoring; the water platform's is developed at the Coastal Marine Environmental Institute - National Research Council (Italy), within the Project: Integrated Systems and Technologies for Geophysical and Environmental Monitoring in coastal-marine areas (STIGEAC), in the framework of the National Operational Programs 2007-2013. The project concerns in the research of new technologies and the design of vehicles, for the surveys of the coastal marine environment, understood as a "multipurpose" laboratory for sea research with characteristics of modularity and portability. The goal involves not only the execution of scientific and technological research but also for the valorization of marine cultural heritage, for industrial activity and for emergency interventions related to environmental crises. Major innovations concern the design of a new architecture of the control system and/or to allow the cooperation between heterogeneous unmanned vehicles, the integration of distributed sensing techniques and real-time image processing capabilities [Marsella et al., 2015].