Underwater optical environments are seriously affected by various optical inputs, such as artificial light, sky light, and ambient scattered light. The latter two can block underwater object segmentation tasks, since they inhibit the emergence of objects of interest and distort image information, while artificial light can contribute to segmentation. Artificial light often focuses on the object...

A new optimized blind equalization algorithm for sparse underwater acoustic channel is proposed in this paper. The decision feedback equalizer is a common nonlinear equalizer to overcome the effect of noise in underwater acoustic communication. The decision feedback equalizer algorithm tracks the underwater acoustic channel change and utilizes the feedback information to adjust equalizer. The g...

Real time multi-channel sliding correlation processing is widely applied in underwater communication system or underwater positioning system. The traditional implementation in FPGA always employs parallel method which reduces the design work, however wastes considerable FPGA resources. This paper described a new kind of SOPC structure which based on AVALON bus, taken NIOS CPU as system controll...

This paper presents a concept for a control system for an autonomous underwater vehicle under ice using a “SLOCUM” underwater glider. The project concept, the separate working tasks for the next one-and-a-half years and the first results will be presented. In this context the structure of the obstacle avoidance system and a simulator structure with a sensor and environment simulation as well as...

recently, data collection from seabed by means of underwater wireless sensor networks (uwsn) has attracted considerable attention. autonomous underwater vehicles (auvs) are increasingly used as uwsns in underwater missions. events and environmental parameters in underwater regions have a stochastic nature. the target area must be covered by sensors to observe and report events. a ‘topology cont...

Based on a fluid-structure interaction analysis (FSIA), the theoretical solution is developed for an integrated spherical shell-damping layer-water interaction system subjected to an internal sinusoidal pressure excitation. The effect of damping layer on reducing underwater noises is investigated. The pressure reduction factor is defined to measure the efficiency of noise reduction by the dampi...

Underwater acoustic channel makes high data rate transmission a very challenging task, due to the extended multipaths delay spread and large Doppler spread [1]-[2]. To increase the data rate or spectral efficiency of underwater acoustic communication, people resort to the spatial structure of the oceans by employing multiple-input, multipleoutput (MIMO) technology. With MIMO technology, very hi...

In the last years, a challenging field of autonomous robotics is represented by cooperative mobile manipulation carried out in different environments (aerial, terrestrial and underwater environment). As regards cooperative manipulation of Intervention-Autonomous Underwater Vehicles (I-AUVs), this application is characterized by a more complex environment of work, compared to the terrestrial or ...

This paper depicts the structural design of a novel water-jet-based spherical underwater robot. The propulsion system is made up of four water-jet thrusters and 8 steering servo motors which can adjust the polydirectional shift of thrusters nozzle to achieve 4-degrees-of-freedom (4-DOF) motion. Every two thrusters nozzles formed an angle of 90 degree in one plane. A bilayer structure was adopte...

The Underwater Swarm is a particular Underwater Network configuration characterized by nodes very close one to each other, with mobility capability. The structure of the network is that of a distributed network, in which the nodes, through the exchange of control information, will take decisions in collaborative manner. This type of network raises challenges for its effective design and develop...