867 research outputs found
Environmental modeling with precision navigation using ROAZ autonomous surface vehicle
The use of robotic vehicles for environmental modeling is discussed. This paper presents diverse results in
autonomous marine missions with the ROAZ autonomous surface vehicle. The vehicle can perform autonomous missions while gathering marine data with high inertial and positioning
precision. The underwater world is an, economical and environmental, asset that need new tools to study and preserve it. ROAZ is used in marine environment missions since it can sense and monitor the surface and underwater scenarios. Is equipped with a diverse set of sensors, cameras and underwater sonars that
generate 3D environmental models. It is used for study the marine life and possible underwater wrecks that can pollute or be a danger to marine navigation. The 3D model and integration of multibeam and sidescan sonars represent a challenge in nowadays. Adding that it is important that robots can explore an area and make decisions based on their surroundings and goals.
Regard that, autonomous robotic systems can relieve human beings of repetitive and dangerous tasks
Guidance and control of an ASV in AUV tracking operations
The following addresses the control of an Autonomous Surface Vehicle (ASV) to follow the trajectory made by an Autonomous Underwater Vehicle (AUV) when the last is performing any given pre-programmed mission. In fact, it has been proved to be of great interest to have an ASV that could follow on the surface and even catch up the trajectory performed by the AUV, when executing a given mission. In order to achieve this desired coordinated motion between AUV and ASV, it would make sense just to program each of the vehicles with the same mission. However, due to the nature of vehicles, missions and also due to the localization system used, with this kind of solution some problems would arise, namely related with timings and synchronization, which are indeed difficult to overcome. The solution proposed here tries to estimate the AUV position, by tapping the signals exchanged between the former and each of the beacons of the acoustic localization network, and control and actuate the ASV in accordance
Development Of A Vision System For Ship Hull Inspection
Penyelidikan ini memperkenalkan strategi pengawalan untuk memperbaiki
prestasi pemeriksaan visual badan kapal dengan menggunakan kenderaan dalam air.
This work introduces a strategy to improve the performance of visual ship hull
inspection using a Remotely-Operated Vehicle (ROV) as its underwater vehicle
platform
Autonomous surveillance for biosecurity
The global movement of people and goods has increased the risk of biosecurity
threats and their potential to incur large economic, social, and environmental
costs. Conventional manual biosecurity surveillance methods are limited by
their scalability in space and time. This article focuses on autonomous
surveillance systems, comprising sensor networks, robots, and intelligent
algorithms, and their applicability to biosecurity threats. We discuss the
spatial and temporal attributes of autonomous surveillance technologies and map
them to three broad categories of biosecurity threat: (i) vector-borne
diseases; (ii) plant pests; and (iii) aquatic pests. Our discussion reveals a
broad range of opportunities to serve biosecurity needs through autonomous
surveillance.Comment: 26 pages, Trends in Biotechnology, 3 March 2015, ISSN 0167-7799,
http://dx.doi.org/10.1016/j.tibtech.2015.01.003.
(http://www.sciencedirect.com/science/article/pii/S0167779915000190
Underwater Robots Part I: Current Systems and Problem Pose
International audienceThis paper constitutes the first part of a general overview of underwater robotics. The second part is titled: Underwater Robots Part II: existing solutions and open issues
Development Of A Vision System For Ship Hull Inspection [K4165. Z94 2007 f rb].
Penyelidikan ini memperkenalkan strategi pengawalan untuk memperbaiki prestasi pemeriksaan visual badan kapal dengan menggunakan kenderaan dalam air. Kaedah yang dicadangkan bertujuan untuk membangunkan sebuah sistem yang secara visualnya sentiasa kekal selari pada permukaan badan kapal.
This work introduces a strategy to improve the performance of visual ship hull inspection using a Remotely-Operated Vehicle (ROV) as its underwater vehicle platform. The proposed method is aimed at developing a system that will maintain the camera viewing angle parallel to the ship hull surface
Guidance and control of an autonomous underwater vehicle
Merged with duplicate record 10026.1/856 on 07.03.2017 by CS (TIS)A cooperative project between the Universities of Plymouth and Cranfield was aimed
at designing and developing an autonomous underwater vehicle named Hammerhead.
The work presented herein is to formulate an advance guidance and control system
and to implement it in the Hammerhead. This involves the description of Hammerhead
hardware from a control system perspective. In addition to the control system,
an intelligent navigation scheme and a state of the art vision system is also developed.
However, the development of these submodules is out of the scope of this thesis.
To model an underwater vehicle, the traditional way is to acquire painstaking mathematical
models based on laws of physics and then simplify and linearise the models to
some operating point. One of the principal novelties of this research is the use of system
identification techniques on actual vehicle data obtained from full scale in water
experiments. Two new guidance mechanisms have also been formulated for cruising
type vehicles. The first is a modification of the proportional navigation guidance for
missiles whilst the other is a hybrid law which is a combination of several guidance
strategies employed during different phases of the Right.
In addition to the modelling process and guidance systems, a number of robust control
methodologies have been conceived for Hammerhead. A discrete time linear
quadratic Gaussian with loop transfer recovery based autopilot is formulated and integrated
with the conventional and more advance guidance laws proposed. A model
predictive controller (MPC) has also been devised which is constructed using artificial
intelligence techniques such as genetic algorithms (GA) and fuzzy logic. A GA
is employed as an online optimization routine whilst fuzzy logic has been exploited
as an objective function in an MPC framework. The GA-MPC autopilot has been
implemented in Hammerhead in real time and results demonstrate excellent robustness
despite the presence of disturbances and ever present modelling uncertainty. To
the author's knowledge, this is the first successful application of a GA in real time
optimization for controller tuning in the marine sector and thus the thesis makes an
extremely novel and useful contribution to control system design in general. The
controllers are also integrated with the proposed guidance laws and is also considered
to be an invaluable contribution to knowledge. Moreover, the autopilots are used in
conjunction with a vision based altitude information sensor and simulation results
demonstrate the efficacy of the controllers to cope with uncertain altitude demands.J&S MARINE LTD., QINETIQ,
SUBSEA 7 AND SOUTH WEST WATER PL
Task priority control of underwater intervention systems: Theory and applications
This paper presents a unifying task priority control architecture for underwater vehicle manipulator systems. The proposed control framework can be applied to different operative scenarios such as waypoint navigation, assisted teleoperation, interaction, landing and grasping. This work extends the results of the TRIDENT and MARIS projects, which were limited to the execution of grasping actions, to other applications taken from the DexROV and ROBUST projects. In particular, simulation results show how the control framework can be used, for example, for pipeline inspection scenarios and deep sea mining exploration
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