In the procedure of designing an underwater vehicle or robot, its maneuverability and controllability must be simulated and tested, before the product is finalized for manufacturing. Since the hydrodynamic forces and moments highly affect the dynamic and maneuverability of the system, they must be estimated with a reasonable accuracy. In this study, hydrodynamic coefficients of an autonomous un...

This paper reports the formulation and evaluation of a centralized extended Kalman filter designed for a novel navigation system for underwater vehicles. The navigation system employs Doppler sonar, depth sensors, synchronous clocks, and acoustic modems to achieve simultaneous acoustic communication and navigation. The use of a single moving reference beacon eliminates the requirement for the u...

Underwater navigation and localization using single range measurements presents low–cost alternative to well established underwater localization systems. In this paper, single range localization with respect to stationary and mobile beacon is presented. Also, observability properties of single range localization systems are given and vehicle trajectories which ensure observability are character...

This paper develops the stability theory of relative equilibria for mechanical systems with symmetry. It is especially concerned with systems that have a noncompact symmetry group, such as the group of Euclidean motions, and with relative equilibria for such symmetry groups. For these systems with rigid motion symmetry, one gets stability but possibly with drift in certain rotational as well as...

In the paper using of the artificial neural networks for determination of coefficients of state equations of underwater vehicle’s motion in a horizontal plane and influence of neuron’s activation function for quality of underwater vehic le’s motion modelling is presented. The recurrent optimization network is used to identify parameters of the underwater vehicle’s dynamics. A structure and the ...

A new underwater object detection method based on joint GravityGradient and Magnetic-Gradient Inversion algorithms is proposed in this paper. Magnetic gradient and gravity gradient anomalies induced by an underwater object can be measured and inversed to estimate the relative changes in distance between underwater object and underwater vehicle. The weight least squares estimation is introduced ...

Significant advances in various relevant science and engineering disciplines have propelled the development of more advanced, yet reliable and practical underwater vehicles. A great array of vehicle types and applications has been produced along with a wide range of innovative approaches for enhancing the performance of unmanned underwater vehicle (UUV). These recent advances enable the extensi...

This paper presents a self-calibration technique for a camera mounted on an underwater vehicle designed to perform the 3D reconstruction of underwater scenes. Our aim is to identify the intrinsic parameters of the camera with methods that are adapted to the operational constraints on Ifremer’s underwater vehicles. The optical system is composed by a single vertical camera located below the unde...