Abstract
Cellular Genetic Algorithms (cGAs) exhibit a natural parallelism that makes them interesting candidates for hardware implementation, as several processing elements can operate simultaneously on subpopulations shared among them. This paper presents a scalable architecture for a cGA, suitable for FPGA implementation. A regular array of custom designed processing elements (PEs) works on a population of solutions that is spread into dual-port memory blocks locally shared by adjacent PEs. A travelling salesman problem with 150 cities was used to verify the implementation of the proposed cGA on a Virtex-6 FPGA, using a population of 128 solutions with different levels of parallelism (1, 4, 16 and 64 PEs). Results have shown that an increase of the number of PEs does not degrade the quality of the convergence of the iterative process, and that the throughput increases almost linearly with the number of PEs. Comparing with a software implementation running in a PC, the cGA with 64 PEs has shown a 45x speedup.

Abstract
This paper briefly presents the main points on the development and testing of an extremum seeking controller used to maximize the longitudinal velocity of surface sailing vehicles by changing the angle of the sail. The algorithm is suitable for sailing purposes since it requires only the measurements of the vehicle's velocity and the sail angle. As an illustration, we present a few simulation results on our previously-obtained sailing yacht simulator, which was developed based on a 4 DOF nonlinear dynamic model for surface sailing vehicles, showing that the proposed extremum seeking controller is capable of maximizing the sailing yacht's speed performance through online sail tuning. Furthermore, the proposed sail optimization algorithm is tested at sea on an experimental platform, i.e. a small scale autonomous sailboat, illustrating the potential of the controller.

Abstract
This paper tackles the problem of localization of an acoustic pinger by a team of cooperative marine robots. A pinger, whose location is unknown, intermittently emits an acoustic ping which is sensed by hydrophones mounted on marine robots. In addition to position, the instant of emission is unknown. A team of robots carrying a total of four hydrophones is therefore (theoretically) required to estimate the position without ambiguity. The precision of the estimate and the uncertainty critically depend on the position of the hydrophones. In order to obtain the best possible estimation, we explore the possibility of using a cooperative method that leads the robots to points where the overall observability is improved.

Abstract
In this paper we investigate the creation of an heterogeneous underwater network with static and mobile assets cooperating together in coordinated missions using acoustic links. Each underwater device combines communication, networking, and sensing capabilities, and cooperates with the other devices to accomplish a given task. The flexibility and capability of the proposed system allows to overcome the limitations of commercial solutions currently available in the market which typically focus on point to point communications. SUNSET framework has been used to provide acoustic communication and networking capabilities to AUVs, ASVs and moored systems developed by the Oceans Systems Group, at the University of Porto, in Portugal. New solutions have been developed and tested allowing to combine together acoustic data transmission and ranging estimation, to control the underwater nodes acoustically and to instruct the vehicles on keeping a given formation using acoustic links. To validate the proposed approach several experiments with increasing complexity have been conducted at the laboratory and in the field. The experimental results confirm the validity, efficiency and reliability of the proposed solution opening to several possibilities for future developments.

Abstract
In this paper, we present an approach to control an autonomous underwater vehicle in the vertical and the horizontal planes while pitching down or up (theta = +/-pi/2). Such a capability is explored in MARES, a small-sized, torpedo-shaped hovering AUV with four degrees of freedom. Despite the fact that roll angle is not controllable, we find a guidance law that makes the vehicle reach any point in the horizontal plane while maintaining the vehicle in the vertical position.

Abstract
It is becoming more and more common to use Autonomous Underwater Vehicles to perform tasks underwater. The use of this vehicles is affordable and its use doesn't raise any significant risk nor does it requires any human intervention. The traditional applications for the use of such vehicles were related with bathymetric tasks. But nowadays AUVs are being more and more used for variety of missions in open water environments, including the inspection of underwater structures and environmental monitoring in diverse oceanographic expeditions. Following some previous work, this paper addresses the problem of bottom following by an Autonomous Underwater Vehicle in an environment which is not previously known. In particular, the focus is on integrating a reactive behaviour based on environment sensing, with the on-board navigation software of the MARES AUV. For this, a guidance algorithm will provide the necessary pitch and depth references to the control layer of the vehicle. While the altitude towards the seabed can be measured with an altimeter, the pitch reference values are based on realtime estimation of the slope of the seabed. By doing so, it is possible to control the vehicle in a way that it will always maintain a constant attitude towards the bottom, and the trajectory followed will remain parallel to bottom, regardless of it's profile. © 2012 IEEE.