In this paper, we discuss the design aspects and the development of the MARES AUV, a 1.5 m long vehicle, weighting 32 kg, designed and built at the University of Porto, Portugal. This vehicle is highly maneuverable, with the ability to move in the vertical plane, controlling pitch and vertical velocity; forward velocity can also be determined, anywhere between 0 and 2 m/s. MARES can easily integrate any new payload within reason, finding applications in a wide range of areas, such as pollution monitoring, scientific data collection, sonar mapping, underwater video or mine countermeasures.

The ocean and the Blue Economy are increasingly top priorities worldwide. The immense ocean territory in the planet and its huge associated economical potential is envisioned to increase the activity at the ocean in the forthcoming years. The support of these activities, and the convergence to the Internet of Things paradigm, will demand wireless and mobile communications to connect humans and systems at remote ocean areas. Currently, there is no communications solution enabling cost-effective broadband Internet access at remote ocean areas in alternative to expensive, narrowband satellite communications. This paper presents the maritime communications solution being developed in the BLUECOM+ project. The BLUE-COM+ solution enables cost-effective broadband Internet access at remote ocean areas using standard wireless access technologies, e.g., GPRS/UMTS/LTE and Wi-Fi. Its novelty lies on the joint use of TV white spaces for long range radio communications, tethered balloons for lifting communications nodes high above the ocean surface, multi-hop relaying techniques for radio range extension, and standard access networks at the ocean. Simulation results prove it is possible to reach radio ranges beyond 100 km and bitrates in excess of 3 Mbit/s using a two-hop land-sea communications chain.

Autonomous sailboats are robotic vessels that use wind energy for propulsion and control the sails and rudders without human intervention. The use of autonomous sailboats for ocean sampling has been tentatively proposed before, but there have been minor efforts towards the development and deployment of actual prototypes, due to a number of technical limitations and significant risks of operation. Currently, most of the limitations have been surpassed, with the availability of extremely low power electronics, flexible computational systems, reliable communication devices and high performance renewable power sources. At the same time, some of the major risks have been mitigated, allowing this emerging technology to become an effective tool for a wide range of applications in real scenarios. We illustrate some of these scenarios and we describe the status of the current efforts being made to develop operational prototypes.

Sailing has been for long times the only means of ship propulsion at sea. Although the performance of a sailing vessel is well below the present power driven ships, either in terms of navigation speed and predictability, wind energy is absolutely renewable, clean and free. Unmanned autonomous sailing boats may exhibit a virtually unlimited autonomy and be able to perform unassisted missions at sea for long periods of time. Promising applications include oceanographic and weather data collecting, surveillance and even military applications. The Microtransat competition, launched in Europe in 2006, has been a key initiative to promote the development of robotic unmanned sailing boats. Various regattas have taken place across Europe and the ultimate challenge will be a transatlantic race. This paper presents an autonomous sailing boat developed at the University of Porto, Portugal, with emphasis on the hardware and software computing infrastructure. This platform is capable of carrying a few kilograms of sensing equipment that can be hooked to the boat's main computer, also providing support for short and long range data communications.

In this work, we address the modeling and control problems in the domain of underwater vehicles. We focus on a prototype of an autonomous underwater vehicle. Although the work presented here is applied to a particular vehicle with four controllable degrees of freedom, the method may be easily extended to several submerged bodies. In the engineering area, modeling of systems is done frequently, as it yields a mathematical translation of their behavior. Since models can become an important tool to solve problems related to its motion or even to the design of controllers, we obtain a model with six degrees of freedom for such a vehicle.Robust control of underwater vehicles is an area in which many efforts were applied over the last two decades. However, due to nonlinear dynamics, it may be hard to design robust controllers that yield the expected behavior, and there is no general procedure to develop them. Here, we propose an approach that combines nonlinear controllers based on the deduced model and on the Lyapunov theory to control the velocities of the vehicle with linear controllers that control the vehicle’s position. We derive control laws to perform several maneuvers, both in the vertical and the horizontal planes, in a decoupled way, which is made possible through the configuration of thrusters. Finally, we present realistic simulations and experimental results that validate the proposed approach in the definition of the control laws.