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Beginning this year, as part of the Crossministerial Strategic Innovation Promotion Program, Next Generation Marine Resources Survey Technologies (Zipangu Plan for the Sea), tools for marine resources survey use will be developed. In this way, the world's first simple undersea work system that can be used for highly efficient sampling of seabed resources etc. will be built with, as its ultimate purpose,...
Robust control methods for underwater manipulators are needed for development of next generation, autonomous underwater vehicle-manipulator systems. For manipulation and intervention in uncertain hydrodynamic environments, vision-based positioning and tracking are essential tasks. In this research, a visual servoing control system is proposed for a two-link electrically actuated underwater manipulator...
The culture of fish in cages has become a practical and successful method in oceans to get good yield in fish production without going to deep sea. Our system contains a fish cage and an electronic system which makes the cage system submerge to a desired depth to protect fish during adverse weather condition. An automatic sub-surface floating fish cage has been developed for deployment in the coastal...
Passive source localization using single hydrophone has received considerable attention in the last decade particularly in marine biological studies. If proven successful, it should find tremendous applications, both in military and civilian. Underwater vehicles such as gliders, AUVs, ROVs, torpedoes, mines, etc. seldom have more than one sensor fitted on them for carrying out reconnaissance/ threat...
The seismometer used in Dense Oceanfloor Network system for Earthquakes and Tsunamis (DONET), is buried under the seabed to suppress the background noise [1]. To make a hole for burying the seismometer, a new caisson installation technique using hydraulic vibration hammer is developed. This paper describes the detail of the hammer, a field test, and a trial test in deep sea.
Acoustic vision systems are gaining prominence due to ocean surveillance for internal security along coastal waters, in particular defence and engineering. Image generation is an effective method for underwater target exploration. Underwater acoustic imaging systems can identify objects according to the characteristic information obtained from the acoustic reflections from the object. Acoustic lens...
The present paper introduces pH sensor named pH-12, ORP sensor named ORP-12, auto multi-water samplers named MINIMONE and ANEMONE, and their applied examples in real waters. They have been developed for the purpose of attaching AUVs and ROVs by our research team, and they are specialized to detect hydrothermal plume signals. In order to mount on AUVs/ROVs, these sensors and samplers are designed as...
Autonomous underwater vehicles that are propelled by altering buoyancy have been in demand in recent years as they have the ability to operate at sea for long periods. The buoyancy of an object in a fluid can be varied by two methods. One method changes the buoyancy of the vehicle by changing the mass without changing the volume and the other varies the buoyancy of the vehicle by changing its volume...
Acoustic bio-sonar characteristics of non-marine toothed whales are very critical for any conservation efforts using passive acoustic monitoring. The acoustic surveys have now been recognized as effective methods for freshwater cetaceans monitoring and abundance estimation compared to the traditional visual surveys. These species have been declared as data deficient by the IUCN and acoustic surveys...
Newly arrived among the autonomous observing platforms, the SeaExplorer glider already confirms its capability to resolve in-situ dynamical features at regional scales and associated biogeochemical processes. Its first long-term mission lasted 60 days with one single battery charge, covered the summer to winter transition and 1 200 kilometers with several transects across the Ligurian Sea (NW Mediterranean),...
The robotics world has reached a stage where the Remotely Operated Vehicle (ROV) industry is very well established with thousands upon thousands of ROVs having been created and deployed since the dawn of this industry. The need for autonomy in robots and vehicles, however, is becoming more and more a prevalent issue in many situations and environments worldwide. The ability to communicate between...
Classification of submerged objects can be performed using broadband sonar and underwater sound scattering analysis. The backscattered signals, composed of specular echo and elastic echo, have information on the submerged target, including its dimensions and material characteristics. In this study, we performed shockwave-scattering simulations of backscattered signals when a broadband shockwave (1–60...
The Ieodo Ocean Research Station(IORS) is an integrated meteorological and oceanographic observation base which was first constructed in Korea. It was constructed at the Ieodo underwater rock located at a distance of about 150 km to the south-east of the Mara-do, the southernmost island in Korea. The structure is of a fixed jacket type installed at a water depth of 40 m. In order to understand the...
The resonant modes of free-flooded ring or cylindrical transducers are studied as a function of aspect ratio and their frequency spectra are determined using finite element analysis. Dependence of resonant frequencies corresponding to various modes of vibrations on its geometry is studied quantitatively. Modes corresponding to mechanical resonances are identified using in-air analysis. Additional...
Maxwell first described the theoretical basis for the propagation of electromagnetic waves in 1873[1]. For the next 140 years we have seen tremendous developments in the area of Wireless Communications. Today, virtually everything in the world is connected by wireless technologies, whether it's on the surface of earth or in the deep space. Surprisingly, an important frontier is left out, which occupies...
This paper describes the different techniques available for extracting mechanical energy from the waves and controls the wave power conversion system. Some sort of control system is necessary to get the maximum power output from the converter. Also the optimum oscillation of wave energy converter is important to get the maximum energy from the wave. In this paper the maximum power production from...
Image compression techniques find an extensive role in the field of underwater image processing. Transform based image compression algorithms efficiency is mainly depending on the decoding methods, adopted. In this work, various decoding techniques such as Embedded Zero Tree wavelet, Set Partitioning Hierarchy Tree, Spatial Orientation Tree, Wavelet Difference Reduction and Advanced Wavelet Difference...
In seafloor seismic observation, the seismometer is usually installed on the seafloor. The data obtained from the seismometer installed on the seafloor is influenced by background noise. Therefore, in seafloor observation, it is necessary to install seismometer with consideration of influence depending on installation environment for observation with high accuracy. We investigated that whether the...
Underwater acoustic source localization is important during disaster-rescue missions ranging from rescuing survivors to recovering acoustically-tagged artifacts such as black box. Designing acoustic localization capabilities reliably and efficiently is challenging. Underwater acoustic localization module (UALM) utilizing multiple signal classification (MUSIC) is implemented on an autonomous underwater...
In the present work, Particle swarm optimisation (PSO) based Tsallis entropy method is employed to segment the buried object SONAR images. This SONAR detects the objects present beneath the seabed in ocean. Objects may be pipelines, and unexploded ordinances buried beneath the seabed. Computer vision for object detection is required when SONAR is equipped in autonomous underwater vehicle. The vehicle...
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