Showing papers on "Intervention AUV published in 2010"

Cooperative positioning using range-only measurements between two AUVs

Abstract: This paper presents a cooperative positioning system between two autonomous underwater vehicles (AUVs). Each AUV is equipped with some navigational sensors. However, AUVs with different tasks have different navigational capabilities. By introducing acoustic communication between AUVs, information from multiple AUVs can be fused to give a more accurate position estimates to AUVs with poorer navigational capabilities. We present results from a field trial where a lawnmower mission is executed by a survey AUV with poor navigational sensors while another AUV with higher positioning accuracy plays the role of a beacon AUV. The beacon AUV's task is to help improve the survey AUV's position accuracy by providing it regular range updates from various locations. An Extended Kalman Filter (EKF) was implemented to fuse the range information updates with the navigational sensor data on the survey AUV. We were able to avoid unbounded error growth in the position estimate of the survey AUV in our experiments through cooperative positioning between two AUVs using range-only measurements.

The Hybrid Glider/AUV Folaga

Abstract: The paper describes the current evolution of the class of Fo?laga underwater vehicles, whose actuation mechanism is a hybrid between oceanographic gliders and standard, self-propelled autonomous underwater vehicles (AUVs). The Fo?laga vehicles have been designed for coastal oceanography and environmental sampling; the application-oriented design approach has resulted in light-weight, low-cost, low-maintenance vehicles. A description of the vehicles' design and guidance, navigation and control capabilities is given, together with data from recent experimental trials.

Antisubmarine warfare applications for autonomous underwater vehicles: The GLINT09 sea trial results

Abstract: Surveillance in antisubmarine warfare (ASW) has traditionally been carried out by means of submarines or frigates with towed arrays. These techniques are manpower intensive. Alternative approaches have recently been suggested concerning distributed mobile and stationary sensors, such as sonobuoys and autonomous underwater vehicles (AUVs). To field a fully operational system, many technological hurdles need to be overcome. These include battery life, limited acoustic communications ranges, incorporating sonar signal processing on the AUV's embedded hardware, and increasing autonomy to ensure that the system as a whole acts in a sensible and appropriate fashion. The main thrust of this paper is how the latter two issues have been addressed for a real experimental system and how the proposed solutions have been demonstrated at sea. This paper describes ongoing development at the NATO Undersea Research Centre (NURC) to construct an autonomous distributed sensor system that uses AUVs for ASW applications. In a series of at-sea experiments, we have demonstrated real-time processing—incorporating traditional ASW processing as far as tracking—and adaptive autonomous behaviors, which concern AUV navigation to optimize target localization. This paper describes the hardware and software configurations that facilitated the rapid development of this system and details the recent at-sea successes that have been demonstrated with our AUV, towed arrays, and active acoustic sources. Results are given of our most recent at-sea trial, GLINT09, held in the summer of 2009, when an AUV with a towed array detected and maneuvered in response to an active source. © 2010 Wiley Periodicals, Inc.

Autonomous Underwater Vehicles as Tools for Deep-Submergence Archaeology

Abstract: Marine archaeology beyond the capabilities of scuba divers is a technologically enabled field. The tool suite includes ship-based systems such as towed side-scan sonars and remotely operated vehicles, and more recently free-swimming autonomous underwater vehicles (AUVs). Each of these platforms has various imaging and mapping capabilities appropriate for specific scales and tasks. Broadly speaking, AUVs are becoming effective tools for locating, identifying, and surveying archaeological sites. This paper discusses the role of AUVs in this suite of tools, outlines some specific design criteria necessary to maximize their utility in the field, and presents directions for future developments. Results are presented for a recent joint AUV-towed system survey and a demonstration of current mine-hunting technologies applied to archaeology.

Design and Deployment of a Four-Degrees-of-Freedom Hovering Autonomous Underwater Vehicle for sub-Ice Exploration and Mapping

Abstract: This paper describes the 2008 and 2009 Antarctic deployments of the National Aeronautics and Space Administration ENDURANCE autonomous underwater vehicle (AUV). The goal of this project was to conduct three autonomous tasks beneath the ice cap 4 m thick of West Lake Bonney: first, to measure the three-dimensional (3D) water chemistry of the lake at prespecified coordinates; second, to map the underwater face of the Taylor Glacier; third, to chart the bathymetry of the lake bottom. At the end of each mission the AUV had to locate and return through a hole in the ice slightly larger than the outer diameter of the vehicle. During two 10-week deployments to Antarctica, in the austral summers of 2008 and 2009, ENDURANCE logged 243 h of sub-ice operational time, conducted 275 aqueous chemistry sonde casts, completed a 3D bathymetry survey over an area of 1.06 km2 at a resolution of 22 cm, and traversed 74 km beneath the ice cap of West Lake Bonney. Many of the characteristics and capabilities of ENDURANCE are s...

Real-time center of buoyancy identification for optimal hovering in autonomous underwater intervention

Abstract: This work addresses the problem of optimal positioning for an intervention AUV, minimizing the energy consumption and improving the stability in orientation. During a generic intervention task, the vehicle is generally maintained in a hovering configuration, thus requiring a 6 DOF control of the vehicle positioning. The choice of roll and pitch, if done arbitrarily, can severely impact the power efficiency of the vehicle, especially in heavy systems, since the center of buoyancy (COB) may not be necessarily aligned over the center of mass (COM). This approach uses an Extended Kalman Filter (EKF) to identify the location of the center of buoyancy relative to the center of mass, thus allowing to compute the working orientation that maintains the COB vertically aligned above the COM. The EKF is implemented online and hence is able to detect movements of the COB due for example to ballast operations. This algorithm has been firstly implemented in simulation and then successfully validated with the SAUVIM (Semi-Autonomous Underwater Vehicle for Intervention Missions) autonomous underwater vehicle. With its weight of about 4 tons, this testbed is an optimal platform for validating the precision of the filter, since a very small variation of the target pitch and roll results in a large restoring torque.

Development of a control system for an Autonomous Underwater Vehicle

Abstract: Work proposes the development of a control system for an autonomous underwater vehicle dedicated to the observation of the oceans The vehicle, a hybrid between Autonomous Underwater Vehicles (AUVs) and Autonomous Surface Vehicles (ASV), moves on the surface of the sea and makes vertical immersions to obtain profiles of a water column, according to a pre-established plan The displacement of the vehicle on the surface allows the navigation through GPS and telemetry communication by radio-modem The vehicle is 2300mm long by 320mm wide It weighs 85kg and reaches a maximum depth of 30m A control system based on an embedded computer is designed and developed for this vehicle that allows a vehicle's autonomous navigation This control system has been divided into navigation, propulsion, safety and data acquisition subsystems

The Ocean Technology Test Bed - From concept to operation

Abstract: The Ocean Technology Test Bed (OTTB) is a multi-functional underwater test facility developed by the Ocean Technology Lab (OTL) at the University of Victoria to serve military, academia, government and industry. The OTTB is located off the coast of Vancouver Island, Canada. It resides in 80m of water and covers 2-square kilometers of the seafloor. A seafloor cable provides power and communication to a recoverable platform. The platform sits inside of an Integrated cabled long baseline Acoustic System (IAS), which provides precision tracking and acoustic communication throughout the OTTB arena. The facility has the tools researchers require to develop new underwater technologies, such as: oceanographic sensors, autonomous underwater vehicles (AUVs); underwater AUV docking systems; guidance, navigation and control algorithms; multiple vehicle cooperation; acoustic communication; and autonomous remote sensors.

New approach for a Reconfigurable Autonomous Underwater Vehicle for Intervention

Abstract: This shows an on-going project named RAUVI (i.e., Reconfigurable AUV for Intervention). This project aims to design and develop an Underwater Autonomous Robot, able to perceive the environment by means of acoustic and optic sensors, and equipped with a robotic arm in order to autonomously perform simple intervention tasks. A complete simulation environment, including this new concept of robot, has been developed and is presented as a preliminary result.

Development of a guidance and control system for an underwater plume exploring AUV

Abstract: In recent years, adaptive and autonomous exploration of underwater plumes with autonomous underwater vehicles (AUVs) becomes a hot research topic, due to its significant applications. For the researches on AUV underwater plume exploring, design, optimization and validation of the control strategies and autonomous behaviors of the AUVs is the key issue. In order to study various control strategies and behaviors on an AUV platform, a stable and reliable low-level guidance and control system should be first designed. In this paper, we proposed a modular behavior-based control architecture, and addressed the design of the guidance module and kinematic variables control module which are the low-level part of the control architecture for an underwater plume exploring AUV. Simulation examples are presented, which demonstrate the good performance of the developed guidance and kinematic variables control system.

Mechanical Design of a Self-Mooring Autonomous Underwater Vehicle

Abstract: The Virginia Tech self-mooring autonomous underwater vehicle (AUV) is capable of mooring itself on the seafloor for extended periods of time. The AUV is intended to travel to a desired mooring location, moor itself on the seafloor, and then release the mooring and return to a desired egress location. The AUV is designed to be an inexpensive sensor platform. The AUV utilizes a false nose that doubles as an anchor. The anchor is neutrally buoyant when attached to the AUV nose. When the vehicle moors it releases the false nose, which floods the anchor making it heavy, sinking both the anchor and AUV to the seafloor. At the end of the mooring time the vehicle releases the anchor line and travels to the recovery location. A prototype vehicle was constructed from a small-scale platform known as the Virginia Tech 475 AUV and used to test the self-mooring concept. The final self-mooring AUV was then constructed to perform the entire long duration mission. The final vehicle was tested successfully for an abbreviated mission profile. This report covers the general design elements of the self-mooring AUV, the detailed design of both the prototype and final AUVs, and the results of successful field trials with both vehicles. Acknowledgments I would like to thank the entire Self-Mooring AUV team at Virginia Tech. Developing and designing the new AUV was a collaborative effort and would not have been possible without everyone who was involved. First, Dr. Wayne Neu and Dr. Daniel Stilwell deserve a great deal of thanks for organizing and advising the team. Thanks to Brian McCarter for basically handling all the electronics of the AUV by himself. I would also like to thank Tim Pratt and Chris Bright for their help with the mechanical design. Thanks to Richard Duelley for designing the propulsion system for the final AUV, as well as handling all the seal testing. Jason Mims also deserves a big thanks for his advice on design and his help with the structural analysis. All photos and figures are owned by the Autonomous Systems and Control Laboratory at Virginia Tech.

A Survey of Autonomous Underwater Vehicle Recent Advances and Future Challenges

Abstract: Autonomous Underwater Vehicle(AUV) has been widely developed for civil and military applications.The potential worthiness of AUV plays an important role in support of educational,scientific and military applications.In this paper,it first surveys the developments and applications on AUV over the world,and AUV development in china.Meanwhile,future technical challenges on AUV are articulated.Finally,the future directions of AUV are outlined.Finally,some suggestions on our way to deal with the situation are dicussed.

ConSys - a new software framework for underwater vehicles

Abstract: Today a large number of autonomous underwater vehicles (AUVs) are evaluated or operated all over the world Most of them use their own control systems created by the vehicle's manufacturer or scientists of different research areas The Fraunhofer Application Center System Technology currently owns three underwater vehicles (both AUVs and remotely operated vehicles, ROVs), a forth is under development All these vehicles have their individual control systems that are very different with respect to changing / creating software modules, mission planning and evaluation These differences are one reason to develop a new software framework for underwater vehicles called ConSys

Development of an intelligent autonomous underwater vehicle, P-SURO

Abstract: P-SURO is a prototype autonomous underwater vehicle (AUV), which is under development as a test-bed for developing underwater technologies such as underwater vision, underwater navigation, and guidance. This vehicle is a hovering type with four thrusters mounted to steer its 6DOF underwater motion, a color camera is mounted at the vehicle's nose for underwater vision, and an AHRS combined with one depth sensor and three range sonars construct an inertial navigation system. In this paper, we report the details of constructions of the vehicle system, and its three core modules - vision module, navigation module, and control module.

Trajectory Planning for Autonomous Underwater Vehicles

Abstract: 1.1 Trajectory planning This chapter is a contribution to the field of Artificial Intelligence. Artificial Intelligence can be defined as the study of methods by which a computer can simulate aspects of human intelligence (Moravec, 2003). Among many mental capabilities, a human being is able to find his own path in a given environment and to optimize it according to the situation requirements. For an autonomous mobile robot, the computation of a safe trajectory is crucial for the success of a mission. Here is the ultimate goal of the trajectory planning issue for autonomous robots:

Alister – Rapid Environment Assessment AUV (Autonomous Underwater Vehicle)

Abstract: ECA is mainly known worldwide for its successful PAP family (mine disposal systems). In the late 1970s, ECA designed the first operational AUV, named EPAULARD for IFREMER. Using its know-how gained over the years in designing and building various types of free swimming and inspection underwater vehicles, ECA decided in spring 2003 to develop the A3000, the first inspection AUV with hovering capabilities. This system was successfully tested in deep water by BP in the Gulf of Mexico in July 2006. All the experience gained during the development and trials of the A3000 have been used to develop and manufacture a Rapid Environment Assessment AUV that was ordered by the French MoD, the end user being the French Navy Hydrographic Service (SHOM). The first part of the presentation will detail the advantages of using AUVs: Level of equipment and tonnage of the vessel needed Reduced manpower Operating footprint unlimited, since an AUV is free swimming, whereas ROV or towed systems have limitations because of their umbilical cables The surface ship can carry out parallel tasks Operation duration is reduced, because the vehicle is not influenced by the state of the sea and the ship’s movements High quality of the data retrieved: this is due to the fact that an AUV operates without an umbilical cable A brief description of the A3000 inspection AUV will then be presented, showing that detailed inspection and identification of underwater objects can already be achieved using AUVs. The paper will then focus on the ALISTER REA AUV with a detailed presentation of the system including its description, performance, suite of sensors (SSS, MBE, SBP, etc.), and results of trials at sea that were conducted in 2007 and 2008.

Acoustic real-time, low-power FPGA based obstacle detection for AUVs

Abstract: The underwater robots called Unmanned Underwater Vehicles (UUVs) take over complex and dangerous underwater missions that were previously performed by humans. These vehicles operate in the unknown environments and make their own decisions within the mission based on the readings of the sensors, without any link with a human operator. Independent of the mission, it is critical for the AUVs to be able to avoid submerged obstacles such as cliffs, wrecks, and floating mines. The AUV typically uses underwater imaging sonar that has several drawbacks for obstacle detection purposes, and therefore requires complex image processing algorithms. Due to the imaging sonar limitations, addressing obstacle detection using conventional software algorithms cannot meet an AUV's real-time, low power requirements. A low-power FPGA algorithm for underwater obstacle detection that is based on local image histogram entropy is proposed. The algorithm maintains a real-time reliable performance while meeting the AUV low power budget.

A Hybrid Propulsion Method for Underwater Vehicle

Abstract: Nowadays, Underwater Vehicles are widely used in ocean environment monitoring, ocean resources exploration and military areas. Therefore, it is required for Underwater Vehicles to have longer work time, wider work space, and what’s more, it is also required for Underwater Vehicles to have the ability to move agilely and locate ccurately. Aiming at those problems, the paper proposes a new hybrid propulsion method for underwater vehicles. The hybrid propulsion which combines water jet ropulsion, vector propulsion and glide propulsion, is the adaptive underwater propulsion that has long-time and low-exhaust work continuation, and can accommodate some emergency. The paper analyzes contrastively the motion performance in adaptive work conditions and prospects its applications at last.

Autonomous Underwater Vehicle for 150m Depth–Development Phases and Hurdles Faced

Abstract: This paper describes the various development phases and the associated hurdles faced during the design, fabrication, sub-system level testing, assembly, integration and overall system testing of an Autonomous Underwater Vehicle (AUV). This AUV has been designed for a depth of 150 m with multi-thruster actuation for shallow water applications. The AUV is having onboard power, electronics and advanced control module, navigation and payload sensors and modular software architecture. During the development of AUV various hurdles like how to power on AUV from outside, loose connections, isolation and grounding, water leakage, battery tripping, etc. have been faced and resolved. The present paper describes the complete development aspects in brief and highlights the various hurdles with remedies throughout the development. The AUV has been tested successfully for various missions at Idukki Lake, Cochin, India up-to a depth of 5m.

Design elements of a prototype self-mooring AUV

Abstract: The Virginia Tech Self-Mooring Autonomous Underwater Vehicle (AUV) is capable of mooring itself on the seafloor for extended periods of time. The AUV is intended to travel to a desired mooring location, moor itself on the seafloor, and then release the mooring and return to a desired egress location. In addition, the AUV is designed to be inexpensive. The self-mooring concept was successfully tested on a small-scale platform known as the Virginia Tech 475 AUV. This report covers the major design elements of the self-mooring AUV, experiments that were conducted to refine the engineering analysis, and the results of successful field trials with this small-scale prototype.

The integrated navigation system of an autonomous underwater vehicle and the experience from its application in high arctic latitudes

Abstract: The experience gained in the creation and practical application of an integrated navigation system for an autonomous underwater vehicle, performing programmed missions under difficult and extreme environmental conditions, is considered. The content, characteristics, and methods for correcting navigational data obtained with the help of onboard autonomous, hydroacoustic, and satellite systems are discussed. The results from full-scale marine tests of a navigational complex of the Klavesin underwater vehicle and the results of its operational testing when working under ice in high Arctic latitudes during investigation of Lomonosov Ridge are presented.

A simulator developed for a twin-pod AUV, the Marport SQX-500

Abstract: A vertically arranged twin-pod autonomous underwater vehicle (AUV) is presently under development in St. John's Newfoundland. A large separation of the centre of gravity (CG) and the centre of buoyancy (CB) can be achieved by placing heavy batteries and payloads in the lower pod and placing the light controller and communication electronics on the upper pod. With the large vertical separation between CG and CB the twin-pod vehicle becomes highly stable in pitch and roll and thus provides an ideal platform for obtaining photos, video and sonar images of the seabed. This paper presents the vehicle motion simulations that have been done in support of this novel AUV design and development.

The Visual Information Derived From the Stereo Camera System Mounted on the Underwater Vehicle

Abstract: The visual information is very important for the operation of an underwater vehicle such as a manned vehicle and a remotely operated vehicle (ROV). And it will be also essential for functions which should be applied to an autonomous underwater vehicle (AUV) for the next generation. Generally, it is got by optical sensors, and most underwater vehicles are equipped with various types of them. Above all, camera systems are applied as multiple units to the underwater vehicles. And they can construct a stereo camera system. In this paper, some new functions, which provide some type of visual information derived by the stereo vision system, are described. And methods to apply the visual information to the underwater vehicle and their utility are confirmed.Copyright © 2010 by ASME

Beneath the horizon [Control Robotics]

Abstract: The sinking of the Deepwater Horizon is a disaster for the personnel who were killed, for the environment, and for deep-water drilling. However, an array of underwater vehicle technology has benefited. The subsea activities being undertaken in response to the tragic incidents aboard the Deepwater Horizon semisubmersible mobile drilling unit (MODU) have been performed by remotely operated vehicles (ROVs). ROVs are underwater robots powered and controlled from a surface vessel or platform via an umbilical. The ROVs used are equipped with dual manipulators and are of a grouping known as 'work-class' (WROV) as they perform the work that would have historically been undertaken by divers in shallow waters.

Maneuverability simulation of a mini autonomous underwater vehicle

Abstract: In order to simulate the under water motion of a mini autonomous underwater vehicle( AUV) and an- alyze its maneuverability,the dynamical characteristic of the mini AUV was researched. The 6-DOF motion equations were founded. Through model experiment with accessory bodies,the hydrodynamics of AUV body including resistance,main inertial and viscous hydrodynamic coefficients was obtained. The hydrodynamics of rudders was gained through theoretical calculation. Simulation computation of the vehicle was carried out through numerical integration of the motion equations. A motion simulation system was constructed. Four typical maneuvers in horizontal and vertical planes were simulated and the maneuverability of the mini AUV was forecasted. The simulation results reflect the basic motion characteristic of mini AUV and validate the feasibility and correctness of the whole system. The simulation system can be a testing platform for the design and debugging of motion controller and an effective tool for the development of AUV.