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The needs of Marine Vehicles have increased day by day according to the utilization benefits and minimum risk during the operation [1]. Some of the main task has proved just only carried by Marine Unmanned Vehicle. One is an Unmanned Surface Vehicle (USV). Which has the ability to do a good observation at sea level or below sea level. This vehicle has a feature in the design, which is where most of...
Methods for using underwater vehicles for mapping and monitoring are developed continuously. These methods developed must be accurate, quantitative and repeatable while being as cost effective as possible. In 2011, 2012, 2013 and 2014 The Norwegian University of Science and Technology (NTNU) Applied Underwater Robotics Laboratory completed surveys in the Trondheim Fjord area. During these surveys...
Cognitive Autonomous Diving Buddy (CADDY) is an FP7 project initiated in February 2014. The key objectives of the project are to develop, implement, and demonstrate in the course of missions at sea the efficacy of a number of innovative systems to assist human divers during the execution of demanding scientific and commercial activities in hazardous underwater environments. At the core of CADDY is...
The annual Autonomous Underwater Vehicle (AUV) Student Competition (aka “RoboSub”) was established in 1998 as a specific member of the class of robotic competitions. After 17 years, we now take stock and look ahead. A modified free form approach is suggested utilizing a developerss kit. Seven core competencies for autonomy are defined, and an approach for rating competition competencies in mission...
Remotely Operated underwater Vehicles (ROVs) play an important role in a number of operations conducted in shallow and deep water (e.g.: exploration, survey, intervention, etc.), in several application fields like marine science, offshore construction, and underwater archeology. In this work we describe the preliminary steps in the development of the set-up of a special ROV addressed to perform the...
In this paper we examine the passive stage in the propulsive cycle of a soft-bodied, pulsed-jet, underwater vehicle and its effect on the resultant thrust. This vehicle consists of an elastic shell which propels itself via the discontinuous expulsion and ingestion of finite slugs of ambient water, resulting in a pulsated routine. The activation routine involves the collapse of the elastic shell via...
Underwater Gliders (UGs) are a type of Autonomous Underwater Vehicle (AUV) that uses buoyancy engines, an energy efficient locomotion, primarily for oceanography. In this paper, control strategies for existing underwater gliders are reviewed. A total of 50 papers indexed by Scopus with keywords control and underwater gliders were reviewed from 1989 to 2014. The majority of gliders use classical controllers,...
This work explores the benefits, in terms of energy cost, of path planning in marine environments showing certain spatial variability. Specifically, extensive computations have been carried out to calculate, by means of dynamic programming, optimal paths on ocean environments with eddies. The length scales of eddies are different for each environment and range from scales of tens to hundred meters...
On the contrary to Lyapunov theory, contraction theory studies system behavior independently from a specific attractor, thus leading to simpler computations when verifying exponential convergence of nonlinear systems. To check the contraction property, a condition of negativity on the Jacobian of the system has to be fulfilled. In this paper, attention is paid to results for which the negativity condition...
This paper deals with the robust control of an Autonomous Underwater Vehicle (AUV), using the ℋ∞ approach for Linear Parameter Varying (LPV) polytopic systems. This method seems to be adapted to this kind of system because of the important non-linearities and the uncertainties on the hydrodynamics parameters. After the presentation of the nonlinear model of the AUV considered for the study, an LPV...
This paper describes a method for station keeping and docking of floating vehicles. We consider the case of a lighter-than-air blimp and that of an underwater robot. Due to the motion disturbances in the environment (currents), these tasks are important to keep the vehicle stabilized relative to an external reference frame. The main difficulties to achieve station keeping and docking are related to...
Autonomous Underwater Vehicles (AUV) are slow-moving small unmanned robots capable of swimming independently below the water surface on pre-defined mission paths and are commonly used for oceanographic exploration, bathymetric surveys and military applications. With the use of appropriate sensors and equipment, AUVs can perform underwater object recognition and obstacle avoidance. Amogh is a miniature...
A new configuration of underwater robotic vehicle, named AQUAD, is presented here. It is a configuration with four thrusters in a plane which is inspired from an aerial quadrotor system. The system is designed considering the hydrodynamic challenges, and mathematically modelled using Newton-Euler approach. A PID controller is used to control the attitude of the system and implemented with the model...
This paper primarily deals with behavior-based control strategy for an autonomous agent to achieve local goal while tracking a desired path/trajectory. The behavior-based control approach addresses multiple control frameworks, which are switched depending on the circumstances, instead of using a uniform control framework. The need to pursue local goals may arise while an autonomous agent e.g., an...
Different types of submersible dredgers are conceived, modeled and even some prototype and full-scale vehicles are built for prospective subsea excavation purposes by various researchers and commercial companies. Most common type of submersible dredgers is tracked vehicle. Walking submersible dredgers are also available which can be further subdivided into passive legged systems (locomotion performed...
Underwater Vehicles have been used in numerous applications and hence are currently gaining research interest. This paper considers the dynamic model of a spheroidal underwater vehicle and its properties. The dynamics of underwater vehicles is unstable and non-linear. A brief account of existing control methods has been presented in this paper for stabilization and motion control of the underwater...
This paper addresses the problem of stabilizing and trajectory tracking control of a remotely operated vehicle (ROV-Observer) in the vertical plane. The underwater vehicle is not actuated in the pitch direction and cannot be locally asymptotically stabilized by continuous feedbacks which are functions of the state only. In the present note, exponential convergence is obtained by considering time-varying...
A real submersible flying boat which is both flight-capable and submersible has hardly been reported yet. In this paper, the Flying Fish created by Beihang University will be introduced to verify the feasibility of this kind of novel aircraft. The Flying Fish achieves its ability to transfer between the air and the water by imitating the flying fish and aquatic birds. The morphological characteristics...
In this paper, we propose a multi-task scheduler by considering the underwater risk assessment for autonomous underwater vehicle. We divide the task scheduler into two parts: a path coordinator and a condition interpreter. The path coordinator finds the minimum cost sequence from several combinations of paths by using a genetic algorithm. The condition interpreter limits high risk paths such as obstacle...
This Document shows the control LQR (Linear quadratic Regulator) PI (Proportional Integral)Vectorial design, which is developed to control the dynamic of a remote operated underwater vehicle ROV, to allow that the vehicle follow a horizontal trajectory autonomously . The results are showed through simulations of following the trajectory of ROV obtaining satisfactory results and complying with the...
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