Showing papers on "Intervention AUV published in 1998"

Acoustic positioning systems. A practical overview of current systems

Abstract: There are existing commercial sources that provide acoustic positioning systems with some capability to navigate unmanned underwater vehicles (UUVs). Some of these systems can be applied to autonomous underwater vehicles (AUVs). Systems are currently available to provide full ocean depth positioning to an absolute accuracy of 5 m and a relative accuracy of <2 m. Also available from these and other sources are shorter range, higher resolution acoustic positioning systems. The paper discusses how these systems are configured and what capabilities they have. A definition of conventional systems and frequency bands is included. In addition to system types, some of the more common problems associated with acoustic positioning systems and some solutions to these problems are outlined. The paper concludes that although some systems, or components readily exist for the AUV community, additional development is required.

Design of a semi-autonomous underwater vehicle for intervention missions (SAUVIM)

Abstract: As the research in the autonomous underwater vehicle (AUV) field intensifies and the necessity of underwater robotic vehicles (URVs) increases, the requirements of an URV have expanded from simple fly-by missions to more complex, intervention missions. The Autonomous Systems Laboratory, Department of Mechanical Engineering, University of Hawaii is in the midst of designing and developing a semi-autonomous underwater vehicle for intervention missions (SAUVIM). The proposed open structure AUV possesses a fully functional manipulator, various mission sensors, and composite pressure vessels enclosed in a flooded composite fairing. The vehicle allows human-intervention from a land-based computer system capable of vehicle path-planning and monitoring.

Development of a visually-guided autonomous underwater vehicle

Abstract: We are developing autonomous underwater vehicles for exploration and inspection tasks. Our objectives are to enable these submersible robots to autonomously search in regular patterns, follow along fixed natural and artificial features, and swim after dynamic targets. We have developed a method of visually-guiding autonomous land vehicles using correlation-based feature tracking to follow targets of interest. We have used this method to fixate on visual features and generate motion commands for the robot. We propose to use feedback from the motion of the visual feature as reinforcement in a network that learns stable control. We are now applying these techniques to the control of our underwater vehicle, Kambara.

3-D motion and depth estimation from sea-floor images for mosaic-based station-keeping and navigation of ROVs/AUVs and high-resolution sea-floor mapping

Abstract: A vision system has been developed in order to support the autonomous operation or operated-assisted missions of AUV and ROV near the ocean bottom. The sea-floor images, acquired by a down-look camera installed on the vehicle, are processed by the vision system in order to detect and estimate its motion in real time. This information is utilized to realize a number of capabilities, including automatic station keeping, navigation and trajectory following, and the construction of a composite (mosaic) image of the sea floor. We describe the system and provide sample results from various experiments for evaluating performance. We also provide examples from ongoing work, planned for implementation on the real-time vision system.

EURODOCKER-a universal docking-downloading recharging system for AUVs: conceptual design results

Abstract: The EURODOCKER project concentrates on the development of a universal autonomous Docking Downloading-Recharging System for AUVs. It shall be suited to various AUVs that are on the market or now under successful development and thus aims at becoming a standard subsystem of the AUV support spread. The project started with a system engineering task, in order to identify the detailed requirements of the EURODOCKER system as a whole. A wide search and collection of information on the characteristics of AUVs that influence the docking system design has been performed and meetings with institutions and people involved in AUV development have been held. This paper illustrates the outcomings of the first activities of the project, dealing with the conceptual design and the contact with the main AUV industry to sum up a trade-off envelope of requirement.

Demonstration of a vision-based dead-reckoning system for navigation of an underwater vehicle

Abstract: This paper describes a dead-reckoning navigation system for hover-capable underwater vehicles operating close to the ocean floor. Navigation is presented as an extension of underwater station-keeping and mosaicking. It combines real-time vision-processing to build a mosaic of the area of interest, an image-based user interface to specify desired vehicle locations, and vision-based dead-reckoning to compute the robot's position in the mosaic. This system provides a high-level interface between the vehicle and the pilot, who specifies the goal (e.g., go to and hover over this feature) instead of the commands to execute the task (e.g., rotate to the left, go forward, stop). Thus, it is an enabling technology for autonomous underwater vehicles (AUV)-for which commanding actuators directly is not feasible-and a useful high-level interface for remotely operated vehicles (ROV). This new capability is the result of our on-going research with the Monterey Bay Aquarium Research Institute (MBARI).

Hugin-an untethered underwater vehicle for seabed surveying

Abstract: Hugin is an untethered underwater vehicle (UUV) intended for bathymetric seabed surveying. This paper presents a description of the vehicle with emphasis on the acoustic instrumentation. The authors specifically describe the integration of the different acoustic systems and how they affect each other. They also summarise the operational results and gives indications with regard to future plans.

Applications of direct 3D motion estimation for underwater machine vision systems

Abstract: Vision can provide unique capabilities under favorable visibility conditions during the operation of intelligent or autonomous underwater vehicles in deep ocean. We describe a real time vision system for positioning and station keeping, navigation, and sea floor image mosaicing. These developments exploit a direct methodology for 3D motion estimation from time varying underwater imagery. We present sample results from experiments for evaluating the performance and accuracy of the system, based on measurements from an independent sensor.

Towards environmental monitoring with the Autosub autonomous underwater vehicle

Abstract: In this paper we describe some of the desirable characteristics of an autonomous underwater vehicle capable of undertaking environmental surveys in the ocean. Several of these characteristics are incorporated in the 7 m long Autosub-1 vehicle which has completed over 120 missions to date in UK and US waters. We review some of the key technological innovations used within Autosub-1 and describe some results from a 110 km survey off the coast of Florida in December 1997. While the survey demonstrated many of the advantages of using an AUV for environmental monitoring the paper concludes with a discussion of technical and procedural areas that still require attention before the use of AUVs can be considered routine.

Romeo goes to Antarctica [unmanned underwater vehicle]

Abstract: Deals with the first operational campaign of Romeo, the latest unmanned underwater vehicle developed at CNR-IAN. Romeo has been designed as an operational testbed to perform research on intelligent vehicles in the real subsea environment. Its main application field is the development of advanced methodologies for marine science. A brief description of the mechanical design and of the control, computing and software architecture of Romeo is given and its exploitation in Antarctica is reported. During the XIII Italian Expedition to Terra Nova Bay (29 October 1997-26 February 1998) it has been used for (a) collecting data about under-ice biological processes, (b) testing under-ice performances of a set of acoustic devices for autonomous navigation and guidance, and (c) collecting benthic data in the Marine Antarctic Specially Protected Area established near the Italian TNB Station.

An integrated navigation system for a long range AUV

Abstract: Presents the basic concepts of an integrated navigation system devised for a long range AUV which has to reach distant mission points while the currents can be only roughly predicted and details on the sea bed are locally known The system includes several basic functions that are under the control of an execution monitor in order to perform re-planning when abnormal conditions are encountered

REDERMOR: an experimental platform for ROV/AUV field sea trials

Abstract: This paper describes the vehicle named REDERMOR. This is an unmanned underwater vehicle (UUV) designed and manufactured by GESMA. The paper fully describes the vehicle and its components, its different versions and how it was designed. The sea trials realised and their main results are presented. This vehicle is now involved in the project Non traditional Navigation in order to increase the autonomy of UUV. Redermor could be considered as an experimental platform for ROV/AUV field sea trials.

Current progress in the development of a solar powered autonomous underwater vehicle (AUV)

Abstract: During the past two years, The Institute for Marine Technology Problems RAS, FEB and the Autonomous Undersea Systems Institute have undertaken a joint program to develop a solar-powered autonomous underwater vehicle (SAUV). This paper will describe this effort, the vehicle design, and the results of this effort to date. The vehicle system relies on the availability of solar energy, and its performance depends on the effective utilization of that energy. Various strategies and algorithms to manage the acquired energy were investigated in detail. The results of this analysis and the design of a solar AUV testbed will be described. The vehicle design is greatly impacted by the necessity of integrating the solar array with the vehicle platform. This results in an unconventional vehicle shape which generates some unique dynamics problems. These will be discussed along with the characteristics of the onboard control system.

A deep sea docking station for ODYSSEY class autonomous underwater vehicles

Abstract: : Under subcontract to the Massachusetts Institute of Technology's (MIT) Sea Grant Autonomous Ocean Sampling Network (AOSN) program, engineers and researchers at the Woods Hole Oceanographic Institution (WHOI) designed, fabricated and operated a deep sea Docking Station for ODYSSEY class autonomous underwater vehicles (AUVs). The docking station provides shelter as well as power transfer and data exchange services for an AUV that is between autonomous midwater missions. The Station is integrated into the main tension member of a deep sea mooring system. A large subsea flotation sphere supports the mass of the Station above the seafloor. A surface expression connected by an umbilical to the Station was capable of bi-directional satellite or radio frequency communications. Primary subsystems of the Docking Station described in this report include a dock controller with multi-sensor support, long duration battery packs, a docking pole with a moving carriage, an inductive link for power and data transfer, and information about how the Station was deployed, operated and recovered.

Software design techniques for the man-machine interface to autonomous underwater vehicles

Abstract: An integrated simulator, which is used in the research and development of autonomous underwater vehicles (AUV), is introduced. It is constructed using the SGI workstation connected to other computers via Ethernet. This simulator can display the scene of the underwater virtual world, describe the motions of the underwater vehicle, and simulate a number of sensors. We use this simulator to develop the software of the intelligent control system for AUV, and study the dynamics of the underwater vehicle, pattern recognition, etc. The use of the simulator can greatly reduce the time and money spent in AUV development and risks in future sea test.

Drag characterization in the autonomous benthic explorer

Abstract: In order for autonomous underwater vehicles to become common tools in oceanography, they must offer suitable survey capabilities. In addition to improving the energy efficiency of the vehicle, efforts can be made to reduce the drag forces. This paper focuses on an experiment developed for the Autonomous Benthic Explorer (ABE) and discusses past and present efforts to extend survey range. The goal is to measure and reduce ABE's drag through an experiment based on simple engineering principles and make recommendations for improved performance. The result is a low-cost, easy-to-use experiment for studying drag. Initial data shows that the technique is successful, however further refinements will increase the quality of measurements.

State estimation and fix of an AUV in real time

Abstract: The GESMA is working on a research project to increase the autonomy of an autonomous underwater vehicle (AUV) in order to realize a complete and important mission without human support. So that the AUV can know its position with precision, two modules are developed. The first one is a state estimator which fuses the data coming from traditional navigation sensors (Doppler, echo-sounder, motion reference unit). The limit of this module concerns the impossibility of carrying out long time missions because of the drift in position which becomes too large after a few minutes or a few hours. We thus added a second module, a state generator which uses the data coming from the sonars and a feature map database to make a fix.

Autonomous Legged Underwater Vehicle (ALUV)

Abstract: : Long term goal is to develop a suite of innovative technologies that converge to provide a unique and effective means for systematic detection and classification of mines in the surf zone (SZ) and on the beach. The most promising technologies will be deployed on an Autonomous Underwater Vehicle (AUV) platform, which will provide a mobile, stable platform for operations in the required regions. The objective is Integrate and demonstrate candidate sensor performance, mobility and object marking/mapping capability in the surf zone environment. The work will involve developing sensors for obstacle or mine detection, discrimination, and classification. The developed sensors will be integrated into the Ariel Autonomous Legged Underwater Vehicle (ALUV), and the resulting platform/sensor combination will be demonstrated in a field test.

An autonomous underwater vehicle as an imaging platform

Abstract: The autonomous underwater vehicle (AUV) offers enormous potential as a platform for sonar equipment requiring a high level of stability. The vehicles can be made to cruise close to the sea-bed allowing the use of high frequency systems, and allowing increased definition. The vehicle independence from surface support vessels allows missions to be performed regardless of sea-state conditions and with a minimum user intervention. The use of AUV docking stations allow virtually continuous surveying to be performed by one or more vehicles, supplied by a single support vessel. This potentially allows larger underwater areas to be surveyed in shorter time periods with fewer costly support vessels. A major limitation of the system is the power supply, which is supplied from batteries and is therefore limited. A system being developed at Loughborough aims to eventually integrate synthetic aperture sonar techniques into an AUV after initial testing using an automated remotely operated vehicle. (6 pages)

A plan of utilization of AUVs in shallow water

Abstract: The usual AUVs are aiming at the use in deep water. However, in port area where the water depth is shallow, the practical use of AUVs can be considered because of the recent progress of AUV technology. We made plan to develop the omnidirectional AUV for port facility inspection. The first test model was manufactured and experiment is started.

THE DEVELOPMENT OF ROVs AND TRAINING EXPERTS IN THE FIELD UNIVERSITY. Of UNDERWATER ROBOTICS IN FAR-EASTERN STATE TECHICAL

Abstract: The purpose of the present report is the account of generalized experience of a completed underwater ROVs using for experts training in FESTU and attraction of foreign colleagues' interest to the experience

An autonomous underwater vehicle as a student project

Abstract: The challenge presented to five fourth-year undergraduate students was to take a "top-down" systems approach to design, construct, programme and test an underwater vehicle operating in a "hands-off" mode. To achieve the aim of semi-autonomous operation, a commercial SEAPUP remotely operated vehicle, with 300 metres of cable, was adapted so that a computer replaced its joystick. The project was treated as a learning process leading ultimately to the design and operation of a true AUV.