Search results for "Remotely operated underwater vehicle"
showing 10 items of 10 documents
Virtual Vehicles Manager: a java virtual reality environment for distributed multi vehicles dynamics control and simulation
2007
This paper describes a lightweight, full portable software environment for development, simulation and control of vehicles. All the software is developed in Java so there are many advantages as portability, multithreading distribution etc. This environment simulates the vehicles integrating their non-linear differential equation systems. The equation systems can easily be modified changing that representation class so it is easy to manage different vehicles. The scenario is displayed as a 3D virtual reality environment in which all the objects are rendered using a combination of 3 d primitive. It is also possible the use of pre-built 3 d objects loaded from files in 3 ds format. The softwar…
Megabenthos Underwater Video (MUV): a new device to evaluate species distribution in hard-to-reach marine areas
2021
A device, called Megabenthos Underwater Video (MUV), was designed and built for the counting and the size estimate of benthic organisms in hard-to-reach areas. Since 2014 Cassiopea andromeda, an invasive alien jellyfish in the Mediterranean Sea with benthic behavior, colonized a recreational harbor (Cala) of Palermo with a stable population. Studying the species distribution in this area with classical methods (such as visual census, ROV, etc.) was not applicable due to the large presence of obstacles (ropes, anchor cables, boats) and to dive difficulties in these types of area. The MUV was tested from 2017 to 2018 for the study of the spatial-temporal distribution of C. andromeda in the Ca…
Fuzzy/Kalman Hierarchical Horizontal Motion Control of Underactuated ROVs.
2010
A new closed loop fuzzy motion control system including on-line Kalman's filter (KF) for the two dimensional motion of underactuated and underwater Remotely Operated Vehicle (ROV) is presented. Since the sway force is unactuated, new continuous and discrete time models are developed using a polar transformation. A new hierarchical control architecture is developed, where the high level fuzzy guidance controller generates the surge speed and the yaw rate needed to achieve the objective of planar motion, while the low level controller gives the thruster surge force and the yaw torque control signals. The Fuzzy controller ensures robustness with respect to uncertainties due to the marine envi…
Low-cost underwater navigation systems by multi-pressure measurements and AHRS data
2017
This paper deals with accurate navigation for underwater remotely operated vehicles. A feasibility study for a multi-pressure device to be mounted on an ROV is presented. The device can provide accurate estimates of a ROV orientation and angular speed. It is based on the well-known total pressure principle, also used in a Pitot tube, and allows reconstruction of static and dynamic pressures, which in turn provide good estimates of the ROV's orientation and rotational speed, respectively. An appealing feature of the proposed device is its ability to provide accurate estimates even for low-speed movements.
Space variant vision and pipelined architecture for time to impact computation
2002
Image analysis is one of the most interesting ways for a mobile vehicle to understand its environment. One of the tasks of an autonomous vehicle is to get accurate information of what it has in front, to avoid collision or find a way to a target. This task requires real-time restrictions depending on the vehicle speed and external object movement. The use of normal cameras, with homogeneous (squared) pixel distribution, for real-time image processing, usually requires high performance computing and high image rates. A different approach makes use of a CMOS space-variant camera that yields a high frame rate with low data bandwidth. The camera also performs the log-polar transform, simplifyin…
Piecewise planar underwater mosaicing
2015
A commonly ignored problem in planar mosaics, yet often present in practice, is the selection of a reference homography reprojection frame where to attach the successive image frames of the mosaic. A bad choice for the reference frame can lead to severe distortions in the mosaic and can degenerate in incorrect configurations after some sequential frame concatenations. This problem is accentuated in uncontrolled underwater acquisition setups as those provided by AUVs or ROVs due to both the noisy trajectory of the acquisition vehicle — with roll and pitch shakes — and to the non-flat nature of the seabed which tends to break the planarity assumption implicit in the mosaic construction. These…
A Low Cost Customizable Micro-ROV for Environmental Research - Applications, Advances and Challenges
2016
Summary Several shallow submarines areas are characterized by considerable releases of hydrocarbon gases, which, during earthquakes or volcanic activity, may suddenly and violently occur. In some instances, changes in chemical and physical properties of gas emissions, which are generated by geothermal systems connected to the volcanoes’ plumbing system, are important precursors of volcanic activity and useful indices for the study of the geothermal field. Furthermore, some superficial structures such faults, landslide slopes or archaeological relics should be studied with such a high detail that geophysical and bathymetric surveys are unable to provide. In response to the needs increasingly…
VISOCAR: an autonomous industrial transport vehicle guided by visual navigation
2003
The authors describe a vision system, called VISOCAR, for mobile robot guidance in industrial environments. VISOCAR is an optically navigating AGV (automatically guided vehicle) that, owing to its local intelligence, can travel automatically in its natural environment, does not need any dedicated floor installations, and does not impose any restrictions on the route network or factory environment. It can navigate accurately on its track and integrate multisensor information to enhance functional redundancy and system reliability. It is shown that the navigation task can be broken down into a hierarchy of goals, which can be attained by functionally independent modules. The system architectu…
UWSim-NET: An Open-Source Framework for Experimentation in Communications for Underwater Robotics
2019
The communication with the remotely operated vehicles (ROV) in underwater applications are usually based on umbilical cables. The increase in the number of ROVs in cooperative interventions motivates the interest in underwater wireless communications. They have a high impact in robotic applications because of their limited performance in underwater scenarios. In this work we present UWSim-NET, an extension of the simulator for underwater robotics UWSim, which is based on the Robot Operating System (ROS). UWSim-NET integrates a communications module based on Network Simulator 3 (NS3) that allows to model the physical and data link layers. Experiments demonstrating the capabilities of UWSim-N…
Teleradiologie nach Röntgenverordnung - beispielhafte Anwendung der Open-Source-Software SecTelMed
2005
Purpose: Establishing a teleradiology connection according to the Rontgenverordnung (RoV) between a peripheral hospital and a university clinic will contribute to improve the radiological emergency treatment on weekends, holidays and at night. It will also better the medical care for patients and help to lower the costs. Materials and Methods: By using the open source software SecTelMed, the radiological picture is transferred via an internet-linked SSH communication server. The integration of the teleradiological data transfer into the actual workflow is attained by using the already existing PACS infrastructure. While its installation is still under construction, it is actually employed f…