In the presence of noncompact symmetry, the stability of relative equilibria under momentum-preserving perturbations does not generally imply robust stability under momentum-changing perturbations. For axisymmetric relative equilibria of Hamiltonian systems with Euclidean symmetry, we investigate different mechanisms of stability: stability by energy-momentum confinement, KAM, and Nekhoroshev s...

Advances in low-power electronics design and wireless communication have enabled the development of low cost, low power micro-sensor nodes. These sensor nodes are capable of sensing, processing and forwarding which have many applications such as underwater networks. In underwater wireless sensor networks (UWSNs) applications, sensors which are placed in underwater environments and predicted ena...

The development of two new classes of commercial underwater robotic vehicles – deep diving work-class remotely operated vehicles and survey-class autonomous vehicles – is being driven by the needs of deep water oil production and deep ocean telecommunication cable operations. This paper presents a survey of the present state and future directions of commercial underwater robotics, examines prin...

Underwater cameras are widely used to observe the sea floor. They are usually included in autonomous underwater vehicles (AUVs), unmanned underwater vehicles (UUVs), and in situ ocean sensor networks. Despite being an important sensor for monitoring underwater scenes, there exist many issues with recent underwater camera sensors. Because of light’s transportation characteristics in water and th...

Today, underwater acoustic communication is developing for its various applications. For signal transmission in underwater using ocean/ sea/lakes/rivers as a medium an appropriate underwater acoustic system is required. The significant characteristic of ocean makes the underwater communication difficult using electromagnetic waves. The characteristics of an acoustic signal make a good candidate...

The paper surveys recent advances in underwater vehicle navigation and identifies future research challenges. Improvements in underwater navigation sensor technology and underwater navigation algorithms are enabling novel underwater vehicles and novel underwater vehicle missions. This paper first reviews advances in underwater navigation sensor technology. Second, advances in deterministic and ...

During the 1990s, numerous worldwide research and development activities have occurred in underwater robotics, especially in the area of autonomous underwater vehicles (AUVs). As the ocean attracts great attention on environmental issues and resources as well as scientific and military tasks, the need for and use of underwater robotic systems has become more apparent. Great efforts have been ma...

In the world of underwater robotics, fish-like structures are able to accelerate and maneuver better than most other artificial underwater vehicles. For these reasons, fish-like robots are well suited for submarine exploration tasks. However, a complete understanding of mechanisms governing the swimming movements of fish-like robots remains elusive, limiting the performance of such underwater r...