A new pair of optical wireless modems has been realized, which exploit Visible Light Communication (VLC) to transmit Ethernet signals through water. The modem prototypes are finally tested in sea waters at La Spezia harbor; they successfully transmitted 10 Mbit/s 10Base-T signals over a up to 10 m, notwithstanding the high turbidity and the strong sunlight. Final tests included the integration with SUNRISE testbed and the use with a moving robot, remotely operated. Commercial components were used to realize the modems; thus, we expect that the key design concepts can be used as a starting point for practical deployment of this technology.

Bio-inspired solutions devised for autonomous underwater robots are currently being investigated by researchers worldwide as a way to improve propulsion. Despite efforts to harness the substantial potential payoffs of marine animal locomotion, biological system performance still has far to go. In order to address this very ambitious objective, the authors of this study designed and manufactured a series of ostraciiform swimming robots over the past three years. However, the pursuit of the maximum propulsive efficiency by which to maximize robot autonomy while maintaining acceptable maneuverability ultimately drove us to improve our design and move from ostraciiform to carangiform locomotion. In order to comply with the tail motion required by the aforementioned swimmers, the authors designed a transmission system capable of converting the continuous rotation of a single motor in the travelling wave-shaped undulations of a multijoint serial mechanism. The propulsive performance of the resulting thruster (i.e., the caudal fin), which constitutes the mechanism end effector, was investigated by means of computational fluid dynamics techniques. Finally, in order to compute the resulting motion of the robot, numerical predictions were integrated into a multibody model that also accounted for the mass distribution inside the robotic swimmer and the hydrodynamic forces resulting from the relative motion between its body and the surrounding fluid. Dynamic analysis allowed the performance of the robotic propulsion to be computed while in the cruising condition.

In the last decade, the underwater activities performed by archaeologists and biologists have benefited from scientific research on the guidance, control, and sensory systems of unmanned vehicles. In fact, because underwater sites of interest are often difficult for divers to access, the use of unmanned vehicle technology to conduct surveys could be quite advantageous. In this paper, a novel and partially-biomimetic underwater robot, referred to as BRAVe (Biomimetic Research Autonomous Vehicle), is presented. For documentation purposes, it is equipped with a hybrid propulsion system, which consists of two different types of thrusters. The thrusters are designed to compensate for their reciprocal flaws in order to achieve a more efficient overall system. Specifically, the biomimetic thruster is employed for its superior energetic efficiency, and the horizontal propellers are exploited for accurate maneuvering. While the documentation and 3D reconstruction of the underwater seabed is a consolidated aspect for the authors, the hybrid propulsion system represents the main innovation of the present work. The increase in efficiency achieved by this propulsion system allows the vehicle to perform a thorough and precise documentation of underwater remains within short distances, while exploiting the maximum possible autonomy. This article discusses the details of the development of all the vehicle compartments and their associated characteristics, focusing on the significance of this technology. In addition, the results of 3D reconstructions extrapolated from images taken during real field missions are presented.

OptoCOMM aims at demonstrating the potential, at physical level, of a communication facility for the SUNRISE platform constituted by an Optical Underwater Wireless Communication (OUWC) module with target performance of 10 Mb/s transmission rate at 10 meters range in shallow medium/high turbidity harbour waters. The module, which is based on blue Light Emitting Diode (LED) units and common photodiodes, is an evolution of the proof-of-principle prototype already proven in laboratory (pool). It will constitute an additional node integrated in the Littoral Ocean Observatory Network (LOON) test-bed of the SUNRISE infrastructures, providing a high speed and short-range communication node, which will complete the capability of acoustic modems already present in the test-bed. Three modules (nodes) will be developed and experimentally demonstrated: one for direct integration with the LOON infrastructures, one, battery powered, to be potentially installed on buoys, Remotely Operated Vehicles (ROVs), etc., and one to be installed on the eFolaga Autonomous Underwater Vehicle (AUV) of the proponents. The paper describes in detail the development of the modems as well as the first lab experiments, where the core technology has been successfully tested.