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Data analysis of an oscillating flapping wing is conducted for developing a transfer function model especially for heave force data series from the CFD environment for different geometries of flapping wings. The wing experiences a combination of vertical and angular oscillatory motion, while travelling at constant forward speed. The vertical motion is induced by the random motion of the ship in waves,...
The deep ocean water (DOW) which has low temperature and high nutrients will be effective for regenerating subpolar/temperate seaweed bed and aquaculture of those seaweeds. In the present study, a semi-enclosed small fishing port near the pumping facility of DOW in Kume Island of Okinawa in Japan is chosen for the field experiment of seaweed bed development, because it could be possible to prevent...
Autonomous sailboats are good candidates for long term oceanic surveys, since they use wind power as their main mean of propulsion. Controlling a sailboat, however, is typically not an easy task due to the high variability in the wind and the side drift of the boat. In this paper, we describe how we design and set up the control architecture that allows Aeolus, the autonomous model sailboat of ETH...
We present a novel method of modeling ambient noise in warm shallow underwater channels. Due to large snapping shrimp populaces inhabiting these regions, the noise process is known to be impulsive and bursty (colored). Conventionally, researchers have used white noise models to simulate snapping shrimp noise. Though efficient in portraying the amplitude statistics, these models fail to represent the...
Underwater environment is characterized by harsh conditions and is difficult to monitor. The CADDY project deals with the development of a companion robot devoted to support and to monitor human operations and activities during the dive. In this scenario the communication and correct reception of messages between the diver and the robot are essential for success of the dive goals. However, the underwater...
While the advantages of operating AUVs within a multi-vehicle scenario are apparent, the complications associated with the underwater environment have provided a barrier preventing the successful operation of a self-organising group of Autonomous Underwater Vehicles (AUVs). Although AUV technology has matured sufficiently to overcome these challenges, the development of suitable coordination algorithms...
An overview of flow simulations for the offshore wind industry is given. The analyses concern blades, turbines and whole wind power farms. Both aerodynamic simulations and hydrodynamic simulations are considered. Applications are taken from the experience of DNV GL Group.
Diving as a profession and sport is and will be one of the most dangerous disciplines known by man. Water is not a natural habitat for humans and people need equipment to breathe underwater. Failure in the breathing apparatus, burst eardrum, decompression sickness and nitrogen narcosis are just a couple of problems which can occur during an ordinary dive and result in injuries, long-term illnesses...
This work presents a low cost RTK-GPS system for localization of unmanned surface vehicles. The system is based on the use of standard low cost L1 band receivers and in the RTKlib open source software library. Mission scenarios with multiple robotic vehicles are addressed as the ones envisioned in the ICARUS search and rescue case where the possibility of having a moving RTK base on a large USV and...
Characteristics of an underwater acoustic channel, which hydro-acoustic modems of the S2C technology can measure and provide to upper layer protocols, were used for evaluation of several important communication metrics and so for evaluation of the modem performance under the actual channel conditions. Particularly, these channel characteristics were used for assessment of the delivery success related...
“Percorsi nel BLU”/“Blue Paths” is a project — carried out by a Science teacher of a Unified School District in La Spezia — aimed for teaching scientific methods trough interactive learning and operational research on marine habitats. SEACleaner, instead, is a project carried out by a National Research Centre — Institute of Marine Sciences ISMAR-CNR — aimed for monitoring the impact of marine debris...
This work describes the development of continuous active sonar (CAS) processing at CMRE. The software uses subband processing to achieve a faster update rate than is possible with pulsed active sonar (PAS). The software development was based on CMRE's PAS processing software, CAINPro, which has been thoroughly tested during previous sea trials and in postprocessing data analysis. Computational efficiency...
The continuous development of design tools and analysis procedures has allowed propeller performances to increase progressively during years following more and more stringent design requirements. High propeller efficiency and avoidance of erosive cavitation are considered nowadays basic requests for a well designed propeller. However this may not be enough to meet the requirements of high added value...
Detecting and monitoring oil spills at sea has become an important issue due to both the increased demand and use of oil based products, and the more careful attention given to environmental protection. Safety in maritime transportation has improved, but contextually the number of vessels along shipping routes has increased, thus raising the risk of accidents occurring. Along with this, also monitoring...
In this paper, we propose a novel object detection algorithm for underwater environments exploiting multiscale graph-based segmentation. The graph-based approach to image segmentation is fairly independent from distortion, color alteration and other peculiar effects arising with light propagation in water medium. The algorithm is executed at different scales in order to capture both the contour and...
Underwater networks that are designed to carry high-priority data at a relatively high traffic load should employ network protocols that emphasize low delay and adequate reliability at the expense of energy. ICRP (Information-Carrying based Routing Protocol), originally proposed by Wei Liang et al. [1] in 2007, is a routing protocol that obtain unicast routing paths by sending data payload as broadcast...
The use of omnidirectional cameras underwater is enabling many new and exciting applications in multiple fields. Among these, the creation of virtual tours from omnidirectional image surveys is expected to have a large impact in terms of science and conservation outreach. These surveys can be performed by Remotely Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs) that can cover large...
In response to growing commercial interest in mining of seafloor massive sulfide (SMS) deposits, there has been ongoing debate about the possible global abundance of SMS [1,2,3,4]. The need for such assessments is now more urgent, as a number of countries, mining and exploration companies, and international consortia have begun to invest in intensive exploration campaigns for SMS. This paper examines...
Within the framework of the Italian national project MARIS (Marine Autonomous Robotics for InterventionS), in this paper a control law based on a virtual decomposition approach for underwater vehicles carrying a n-degrees-of-freedom manipulator is presented. The control law, already known in the literature, has been customized for the specific set-up of MARIS. Being based on the Newton-Euler formulation,...
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