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Ocean Environmental data is a key component utilized by the United States Coast Guard (USCG) when developing and executing a search and rescue mission. The Search and Rescue Optimal Planning System (SAROPS) became operational with the USCG in 2007 and is the main tool for developing search and rescue mission plans. This tool utilizes environmental data (wind, ocean currents, etc.) to estimate the...
Underwater vehicles are usually designed with additional degrees of freedom than those required to accomplish given manipulator tasks. A robot platform should be effective to maintain its position and orientation in order to attain diverse underwater tasks. This study addresses the dynamic modeling of an autonomous underwater vehicle (AUV) which consists of tilting thrusters for hovering motion to...
Flooding disasters have led to heavy costs including enormous property losses and casualties. The biggest challenge lies in rescue operation is the low efficiency and the high security risk of rescuers, which is also a problem focused on by this work. Unmanned system is one of the solution that replace people in the rescue operation. However, there are still some obvious defects of unmanned system...
This paper proposes a method for attitude estimation that utilizes the depth measurement as well as the MEMS-AHRS (Micro-electromechanical systems Attitude Heading Reference System). Estimating attitude in real-time is crucial for navigation of an unmanned underwater vehicle since path planning, trajectory tracking, and collision-avoidance is based on the attitude information. Many of the attitude...
Classical GPS/Acoustic positioning techniques using ranging position location in low depth environment suffer from the bad system geometry. The aim of this article is to propose a new hyperbolic position location technique that takes into account the system geometry. In our approach we process the position with the normal distribution of the beacon location defined as a sum of uniform distributions...
Malaysian Airlines Flight 370 disappeared on 8 March 2014, while flying from Kuala Lumpur, Malaysia, to Beijing, China. A piece of marine debris, later confirmed to be a flaperon from Flight 370 by the French prosecutor, was found on Réunion Island in the western Indian Ocean on 29 July, 2015. The aircraft debris are assumed to drift in the surface layer and the vertical movement is not taken into...
This paper used DIDSON to get information of underwater fish and carried out the real-time multiple-target tracking, particularly the targets were dense. Analysis of fishery resources was also done through the data post-processing. Realtime data processing mainly included DIDSON image building/enhancement/filter, target detection and multiple-target tracking. Nearest neighbor clustering algorithm...
Dynamic behaviors of AUV show a complex six-degrees of freedom (6-DOF) motion. They have great influence on the task precision and are influenced by uncertain marine environment parameters, in which influence of the lateral flow is one of the most significant. In this paper, dynamic behaviors of AUV in lateral flow are investigated using the CFD-based numerical method. Pressure distribution on the...
In this paper, considering the mobility of the sensor network, a novel mobility aware medium access control protocol is discussed, which applies to the problem of utilizing mobile nodes to collect data from underwater sensor networks. The proposed underwater mobility aware medium access (UW-MMAC) protocol, based on a hybrid of random and deterministic access, can be divided into two phases. The first...
The underwater vehicle-manipulator system (UVMS) is basically a redundant system. Hence, this redundant system can have various combinations of joint velocities that do not affect the given velocity profile of an end-effector and this may induce a self-motion of a vehicle. In the current paper, the performance index based on the concept of Zero Moment Point(ZMP) is proposed to enhance the stability...
To solve the trajectory tracking problem of underwater vehicles in the presence of unknown dynamics and external disturbances, a double-loop adaptive integral sliding mode controller that yields chattering-free performance is proposed in this paper. The designed double-loop controller consists of an outer-loop position controller (the kinematic controller) and an inner-loop velocity controller (the...
Knowledge of a flow field is crucial to guide oceanic mobile sensing platforms; yet, existing regional ocean models provide insufficient spatial and temporal resolutions for precise guidance of mobile platforms. By combining computational ocean models with real-time data streams collected from mobile platforms, generic environmental models (GEMs) provide high-resolution predictions of ocean currents...
In this paper, a path planning system is proposed for optimal motions of underwater glider in three-dimensional (3D) space. Inspired by the Dubins Paths consisting of straight lines and circular arcs, this paper presents the 3D Dubins curve to accommodate the characteristic glider motions, including sawtooth motion and spiral motion. This modified 3D Dubins scheme is combined with genetic algorithm...
The method of formation of smooth trajectories of the AUV movement during performing of missions in unknown environment is offered in paper. This method is based on use of the data from their onboard sensors of a distance and allows to correct the trajectory defines by means of Bezier's splines of the third order during AUV movement. Use of the offered approach allows to provide high precision and...
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