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UUST 2013

August 12, 2013


Final Agenda

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AquaPix – A Low-Cost Interferometric Synthetic Aperture Sonar for AUVs: Sea Trials and Results

August 12, 2013
Shea D, Crocker P, Dillon J, Chapman S, AquaPix – A Low-Cost Interferometric Synthetic Aperture Sonar for AUVs: Sea Trials and Results, UUST 2013, Aug 12 2013

Abstract— Kraken Sonar Systems Ltd, based in St. John’s, Canada, produces an Interferometric Synthetic Aperture Sonar (InSAS) system, suitable for integration on a wide range of AUVs and towed platforms. In 2012, Kraken entered into a Cooperative Research and Development Agreement (CRADA) with the Naval Undersea Warfare Center (NUWC) in Newport, Rhode Island. This paper seeks to present a background of Kraken’s InSAS technology, and detail the results of the CRADA. The primary focus of the paper (and the CRADA) is the integration and testing of an AquaPix InSAS on NUWC’s medium-sized 12.75” diameter REMUS600 AUV, manufactured by Hydroid. Kraken designed a payload section for the R600, and assisted NUWC operators with integration onto the AUV. After a very short integration, the resulting integrated SAS-AUV was able to produce ultra-high resolution 3cm imagery and co-registered 25cm bathymetry with no vehicle re-tuning necessary. The main conclusion from this trial was objective evidence that SAS is achievable on medium sized AUVs without extensive tuning or additional control planes.

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Sabertooth a Seafloor Resident Hybrid AUV / ROV System for Long Term Deployment in Deep Water and Hostile Environments.

August 12, 2013
Siesjö J, Roper C, Furuholmen M, Sabertooth a Seafloor Resident Hybrid AUV / ROV System for Long Term Deployment in Deep Water and Hostile Environments, UUST 2013, Aug 12, 2013

Increasing use and complexity of subsea installations has put focus on the costs of maintaining these systems. In addition, access to these systems is sometimes limited by adverse weather and ice conditions. Conventional methods for intervention, maintenance and repair (IMR) using surface ships and ROV’s are very expensive furthermore response and mobilization times can be fairly slow.

To address this Saab Underwater Systems has developed a hovering Hybrid AUV/ROV system to remotely perform IMR without or strongly reduced need for a supporting ship. This system is based on the Double Eagle SAROV, a hovering Hybrid AUV/ROV in production for the military market and proven components from Saab Seaeye ROV product range.

This paper will present the Seaeye Sabertooth subsea resident AUV/ROV system, its concept of operation, design and the cooperation project between Saab and Aker Solution. It will also present the ongoing Sabertooth tests and trials conducted together with Tecnomare and Chevron.

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Slocum Glider Expanding the Capabilities

August 12, 2013
Jones C, Allsup B, Webb D, Slocum Glider Expanding the Capabilities, UUST 2013, Aug 12 2013

Teledyne Webb Research (TWR) provides here an overview of the latest Slocum G2 features including the hybrid thruster, increased buoyancy pump displacement, new sensor suites, and an update on the energy harvesting Slocum Thermal E Twin. Three main mission objectives will be reviewed: polar regions, acoustic data telemetry, and long duration transects approximating the course of the Challenger expedition of 1872-76.

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Autonomous Transient Ocean Event Monitoring (ATOEM)

August 11, 2013
Ulmer K, Autonomous Transient Ocean Event Monitoring (ATOEM), UUST , Aug 11 2013

A novel conceptual design is presented for a research platform for Autonomous Transient Ocean Event Monitoring
(ATOEM). In simplest form, ATOEM would be an autonomous diesel-electric submarine of conventional design, but stripped of all of its requirements for human occupation and life support, and whose “torpedo” tubes would instead be loaded with a variety of AUV configurations (e.g., benthic, photic zone and midwater) capable of autonomous docking with the “mother ship”. Global deployment of a large fleet of modular, low-cost, highly-manufacturable ATOEM
platforms has the potential to transform oceanographic research by providing coordinated, comprehensive, time-series, spatiotemporal measurements of all key ocean properties on an unprecedented scale.

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Phased Array Velocity Sensor Operational Advantages and Data Analysis

August 22, 2011
Burdyny M, Poroy O, Spam P, Phased Array Velocity Sensor Operational Advantages and Data Analysis, UUST 17, Aug 2011

Abstract

In recent years the underwater navigation industry has expanded into more diverse and unique applications requiring a greater capability from its platform sensor set. Teledyne RD Instruments has answered the demand with a new patented Phased Array technology to be used as part of the growing Doppler Velocity Log and Acoustic Doppler Current Profiler Product Lines. This new technology derives a fundamental set of advantages over the standard Piston Array. It exhibits how the new Phased Array utilizes a single array transducer composed of multiple elements where four individual acoustic beams are electronically formed at their defined angles. In contrast the existing piston transducer technology utilizes the four individual ceramics where each beam is projected at its respective mounting angle. This yields the opportunity to increase the size of the single array while reducing the overall transducer size giving way for the characteristics which provide for operational improvement.

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SUB-ICE EXPLORATION OF AN ANTARCTIC LAKE: RESULTS FROM THE ENDURANCE PROJECT

August 22, 2011
Richmond K, Sub-Ice Exploration of an Antartic Lake - Results from the Endurance Project, UUST 17, Aug 2017

Abstract

The ENDURANCE autonomous underwater vehicle was developed and deployed to explore and map a unique environment: the waters of Lake Bonney in Taylor Valley, one of the McMurdo Dry Valleys of Antarctica. This permanently ice-covered lake presented several unique challenges and opportunities for exploration and mapping with an AUV. ENDURANCE was successfully deployed in the west lobe of Lake Bonney in the 2008-2009 and 2009-2010 austral summer seasons, completing the rst full synoptic 3-D chemical prole and high-resolution 3-D geometric mapping of such a body of water. ENDURANCE successfully traversed the entire 1 km x 2 km lobe of the lake, including successful automated spooling of a science payload and automated docking into a deployment/recovery melt hole 0.25 m larger in diameter than the vehicle.

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Unmanned Maritime Systems Current Status

August 22, 2011
Ashton D, Unmanned Maritime Systems Current Status, UUST, Aug 2011

Current Staus of US Navy'a Unmmaned Maritime Systems Program Office PMS 406. Presented at the 17th Unmanned Untethered Submersible Technology Conference in Portsmouth NH on 22 August 2011.

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A Mission Oriented Metric to Assess the Benefits of Biologically Inspired Propulsion

August 21, 2011
Licht S, Isreal S, A Mission Oriented Metric to Assess the Benefits of Biologically Inspired Propulsion, UUST, 21 Aug 2011

In this study, we quantify the potential mission specific benefits of biomimetic propulsion as a function of environmental conditions and operational requirements for a small unmanned underwater vehicle (UUV) mission. The benchmark mission requires the UUV to persist in shallow water for 24hr within a specified radius around the desired station, preceded and followed by a 40km transit

The achievable time on station for the nominal vehicle using biologically inspired propulsion is compared to that of the same vehicle using currently available thrusters. The comparison is carried out across a range of sea-states, with varying requirements for station keeping precision, and with a range of assumptions about the performance improvements provided by biomimetic propulsion. The expected magnitude and frequency of wave disturbances in shallow water are generated using U.S. Army Corps of Engineers guidelines for harbor design and construction.

If biomimetic propulsors can deliver on the promise of significantly improved effectiveness in generating low speed maneuvering forces, fin propelled vehicle can perform a high precision 24 hour station keeping mission in 3x higher waves than the thruster propelled vehicle. In rough conditions, the fin propelled vehicle can perform the mission with 10x higher precision.

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USING BIO-INSPIRATION TO IMPROVE CAPABILITIES OF UNDERWATER VEHICLES

August 21, 2011
Murphy A, Haroutunian M, USING BIO-INSPIRATION TO IMPROVE CAPABILITIES OF UNDERWATER VEHICLES, UUST, 21 Aug 2011

There are over 750,000 marine species ranging in size from a few micrometers to dozens of meters, all of which, through the natural process of evolution, have arrived at “successful” solutions to surviving and operating in the ocean space.

Many of these species have capabilities and functionality which have much in common with the engineered capabilities required for underwater vehicles e.g. propulsion/locomotion, manoeuvrability/agility and the ability & resilience to operate at depth. Indeed, in many examples, it appears the biological solutions exhibit superior performance compared to the technological alternative, yet in biology these capabilities are achieved by different and diverse means.
In this research an extensive study on the capabilities of marine animals has been conducted in relation to the equivalent capability on AUVs. And the biological solutions to propulsion, agility, depth and vehicle (or animal) architecture have been focused on. This paper will present the approach adopted, some specific studies and key results from using a bio-inspired approach to improving AUV engineering capabilities.

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Development of a Magetometry System for an Underwater Glider

August 21, 2011
Claus B, Bachmayer R, Development of a Magetometry System for an Underwater Glider, UUST, 21 Aug 2011

The development of a magnetometry system for an underwater glider is detailed in this paper. The system is designed for low noise, low sampling rates and high accuracy measurements. The integration progress into a 200 m Slocum Electric glider is presented in addition to an evaluation of the electrical and system noise levels. A calibration algorithm is evaluated for correcting sensor errors as well as hard and soft magnetic effects due to the glider.

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UUV POSITIONING USING SIDE-SCAN FEATURES

August 21, 2011
Russell J, Bourgeois B, Avera W, UUV POSITIONING USING SIDE-SCAN FEATURES, UUST, 21 Aug 2011

This paper presents an architecture used to improve the navigation in UUVs by applying techniques that reduce vehicle position error growth during extended underwater operation. The techniques improve the navigation by reducing the horizontal vessel position error using navigation bottom fixes created from bottom objects detected in the overlapping
regions of side-scan sonar imagery. The architecture introduces a unique hybrid approach to feature detection and matching by combining both automated and manual methods. The details of a dynamic linear error model incorporating the drift in a typical INS\DVL navigation system are provided. The error model assigns a circular error to the horizontal position of the UUV using system specifications, in-field calibration measurements, or system provided error estimates. Results using real UUV navigation data from a REMUS 600 vehicle demonstrate the architecture's ability to significantly improve the navigation by reducing horizontal vessel position error using bottom fixes created from sidescan imagery.

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Feature Based Navigation for a Platform Inspection AUV

August 21, 2011
Tangirala S, Debrunner C, Feldman W, Fettinger A, Feature Based Navigation for a Platform Inspection AUV, UUST, 21 Aug 2011

Under the Offshore Platform Inspection System (OPIS) program, an LM AUV, the MARLIN(TM), is being outfitted with a mission package which includes a 3D imaging sonar and processors in order to inspect and build 3D models of subsea structures, and to detect large scale damage to these structures relative to a reference model. A key component of this model building and change detection functionality is a process by which sonar data is aligned to the reference model and the vehicle/sensor pose is recovered. An interesting by-product of this is the use of this recovered pose for feature based navigation. This paper presents a method to fuse the estimated pose from an inertial navigation system with the pose recovered from the alignment of sonar data with a reference model, and the use of this fused estimate in vehicle guidance, 3D model building and change detection, and to improve inertial navigation performance. While the technology is developed for an underwater platform inspection system, the methods have broader applicability. Results are presented to demonstrate the performance of the feature-based navigation system.

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Intelligent Planning and Assimilation of AUV - Obtained Measurements within a ROMS - Based Ocean Modeling System

August 21, 2011
Davini B, Choboter P, Clark C, Intelligent Planning and Assimillation of AUV - Obtained Measurements within a ROMS - Based Ocvean Modeling System, UUST, Aug 21 2011

Abstract
An efficient method is presented for collecting oceanic data with autonomous underwater vehicles (AUVs) and assimilating that data into a numerical ocean model. A system based on the data assimilation tools of the Regional Ocean Modeling System (ROMS) is developed that intelligently plans for and integrates AUV measurements with the goal of minimizing model standard deviation. An algorithm for selecting AUV paths is described that seeks to improve the model accuracy by gathering data in high-interest locations. This algorithm and its e ect on the ocean model accuracy are tested by comparing the results of missions made with the algorithm (i.e. optimial) with missions that follow a standard lawn-mower pattern (i.e. non-optimal). The results of the experiments demonstrate that the system is successful in improving the ROMS ocean model accuracy. Also shown are results comparing optimized missions and non-optimized missions.

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Towards Amphibious Robots: Asymmetric Flapping Foil Motion Underwater Produces Large Thrust Efficiently

August 23, 2009
Licht S, Wibawa M, Hover F, Triantafyllou M, Towards Amphibious Robots: Asymmetric Flapping Foil Motion Underwater Produces Large Thrust Efficiently, UUST, 23 Aug 2009

The development of amphibious robots requires actuation that enables them to crawl as well as swim; sea turtles
are excellent examples of amphibious functionality, that can serve as the biomimetic model for the development of amphibious robots.

In this paper we have implemented the observed swimming kinematics of Myrtle, a green sea turtle Chelonia Mydas residing in the Giant Ocean Tank of the New England Aquarium, on the 1.5-meter long biomimetic vehicle Finnegan the RoboTurtle. It is shown that these kinematics result in outstanding performance in (a) rapid pitching, and (b) rapid level turning. The turning radius for the rigid hull vehicle is 0.8 body lengths, a remarkable improvement in turning ability for a rigid hull vehicle.

Still Finnegan’s performance lags the live turtle’s performance by about 20%. Careful observations have shown that turtles employ a fin motion in-line with the direction of locomotion; this degree of freedom was not available to the Finnegan fins, as presently designed. Experimental tests on a flapping fin equipped with this third degree of freedom have shown that the in-line motion enhances the fin’s performance.

This hydrodynamic result is doubly beneficial to an amphibious robot, because it allows for further enhancements in the hydrodynamic function of fins, while the in-line motion allows the same fins to be used for crawling on land.

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Onboard Adaptive Control of AUVs using Automated Planning and Execution

August 23, 2009
Rajan K, Py F, McGann C, Ryan J, O'Reilly T, Maughan T, Roman B, Onboard Adaptive Control of AUVs using Automated Planning and Execution, UUST, 23 Aug 2009

In this paper we describe an integrated goal-oriented control architecture for onboard decision-making for AUVs. Onboard planning and execution is augmented by state estimation of perceived features of interest in the coastal ocean, to drive platform adaptation. The partitioned architecture is a collection of coordinated control loops, with a recurring sense, plan, act cycle and which allows for plan failures to be localized within a control loop and ensures a divide-and-conquer approach to problem solving in dynamic environments.

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Hovering Autonomous Underwater Vehicle - System Design Improvements and Performance Evaluation Results

August 23, 2009
Vaganay J, Gurfinkel L, Elkins M, Jankins D, Shurn K, Hovering Autonomous Underwater Vehicle - System Design Improvements and Performance Evaluation Results, UUST, Aug 23, 2009

The Hovering Autonomous Underwater Vehicle (HAUV) was initially jointly developed by Bluefin Robotics and the Massachusetts Institute of Technology for ship hull inspection under Office of Naval Research (ONR) funding. In 2008, under PMSEOD’s “Explosive Ordnance Disposal Hull Unmanned Underwater Localization System” program (EOD HULS), Bluefin conducted a major vehicle redesign in order to improve the system’s performance and bring it up to the EOD HULS specification. The EOD HULS HAUV system consisting of two vehicles and topside / support equipment was delivered in October 2008. It underwent the Engineering Evaluation phase of the Requirement Compliance Test and Evaluation (RCT&E) of the EOD HULS acquisition program by the Government in December 2008 in San Diego California. It is currently undergoing User Operational Evaluation with the Navy’s Mobile Diving and Salvage Unit 2 (MDSU-2) in Little Creek Virginia.

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Hybrid Glider Propulsion Module Implementation and Characterization

August 10, 2009
Claus, B. “Hybrid Glider Propulsion Module Implementation and Characterisation,” in Unmanned Untethered Submersible Technology, 2009.

A propulsion module is presented for augmenting the performance of ocean gliders. The proposed module implements a folding propeller and magnetic coupling to allow for intermittent use and minimal power requirements at low levels of thrust. To characterize the propulsion module bollard and open water thrust tests are presented and the relative benefit of the use of a folding propeller over a fixed propeller is shown.

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Design and Deployment of a 3D Autonomous Subterranean Submarine Exploration Vehicle

August 19, 2007
Design and Deployment of a 3D Autonomous Subterranean Submarine Exploration Vehicle

The NASA Deep Phreatic Thermal Explorer (DEPTHX) project is developing a fully autonomous underwater vehicle intended as a prototype of the Europa lander third stage that will search for microbial life beneath the ice cap of that Jovian moon. DEPTHX has two principal objectives: First, to develop and test in an appropriate environment the ability for an un-tethered robot to explore into unknown 3D territory, to make a map of what it sees, and to use that map to return home; and second, to demonstrate that science autonomy behaviors can identify likely zones for the existence of microbial life, to command an autonomous maneuvering platform to move to those locations, conduct localized searches, and to autonomously collect microbial life in an aqueous environment. The concept and prototypes are being tested in an unusual terrestrial analog that presents many of the likely morphologic regimes where life may exist on Europa: the 300- meter-deep (or more) hydrothermal cenote of Zacatón, Mexico, which contains diverse microbial mats, but remains uncharted, both spatially and biologically.

In this presentation we summarize the final vehicle architecture and control systems approach to autonomous exploration in fully 3D environments in which apriori knowledge of the environment is non-extant and for which there exists no external navigation system. The latest field work at Cenote La Pilita will be presented describing the February 5, 2007 mission during which DEPTHX became the first fully autonomous cave exploring robot.

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A General Purpose Command Fuser for Action Selection

August 19, 2007
Packer A, A General Purpose Command Fuser for Action Selection, UUST 19 Aug 2007

Command fusion is a fundamental problem in Robotics and has received considerable attention in the research
community. Several methods have been proposed that have been shown to be effective under certain conditions. This paper presents a novel method of combining multiple low-level behaviors while maintaining the high-level mission. In this approach, charts are created for each domain and the command fuser combines them in a fashion that is responsive to the immediate need (low-level behaviors) while continuing to maintain a high-level view. The
approach has been tested on simulators and the results are presented.

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DESIGN OF AN UNDERWATER VEHICLE FOR SUBTERRANEAN EXPLORATION

August 21, 2005


The NASA Deep Phreatic Thermal Explorer (DEPTHX) project is developing a fullym autonomous underwater vehicle intended as a prototype of the Europa lander third stage that will search for microbial life beneath the ice cap of that Jovian moon. DEPTHX has two principal objectives. The technology goal is to develop and test in an appropriate  environment the ability for a bot to explore into unknown 3D territory, to make a map of what it sees, and to use that map to return home. The science goal is to demonstrate that silicon intelligence can autonomously identify and collect microbial life in an aqueous environment.

The concept and prototypes will be tested in an unusual terrestrial analog that presents many of the likely morphologic regimes where life may exist on Europa, including irregular vertical surfaces, an open water column, floor sediments, and potential hydrothermal vents. The site is the 330- meter-deep (or more) hydrothermal cenote of Zacatón, Mexico, which contains diverse microbial mats, but remains uncharted, both spatially and biologically. The site offers an extraordinary opportunity to test the principles and hardware under development.

In this presentation the authors will summarize the overall vehicle architecture and control systems approach to autonomous mobility in fully 3D environments in which apriori knowledge of the environment is nonextant. The latest field work at the Zacaton cenote using a drop sonde variant of the DEPTHX vehicle core navigation components will be presented along with the current 3D map to -280m, created by co-registration of LADAR and sonar data.

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MODELING HYBRID ENERGY SYSTEMS FOR USE IN AUVS

August 21, 2005
Griffiths G, Reece D, Blackmore P, Lain M, Mitchell, Jamieson J, MODELING HYBRID ENERGY SYSTEMS FOR USE IN AUVS, UUST, 21 Aug 2005

Specifying an energy source for an AUV is usually a compromise between performance and cost. For most vehicles and most missions, high specific energy primary lithium batteries are not a practical option due to cost. One solution that shows promise and affordable cost is to use a hybrid approach that combines low cost secondary batteries with a fuel cell or combustion energy source. Exploring the design space for these more complex energy systems requires suitable tools for modelling and assessment. One such tool is Virtual Test Bed. To build confidence in the tool, its simulations have been assessed against experimental data for 18650 lithium ion cells and a Ballard fuel cell, with encouraging results. Subsequently, a conceptual design for a lithium ion battery and fuel cell hybrid energy source was modelled and the performance of two variants assessed for two different 7-day mission scenarios. In both cases, the hybrid system exhibited a specific energy comparable to primary lithium manganese dioxide batteries, with full account taken for the mass overhead of realistic reactant storage for the fuel cell.

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SAUV II High Level Software Architecture

August 21, 2005
Chappell S, Mupparapu S, Komerska R, Blidberg D, SAUV II High Level Software Architecture, UUST, Aug 21, 2005

In January of 2003, the Autonomous Undersea Systems Institute (AUSI) joined with Falmouth Scientific, Inc. (FSI) and Technology Systems Inc. (TSI) to develop the second generation Solar powered Autonomous Underwater Vehicle (SAUV) II. The first generation SAUV was developed by AUSI along with the Institute of Marine Technology Problems (IMTP) [Ageev et. al., 2001] and served as a proof of concept for solar re-powering of an AUV.

The SAUV II development effort has been a team based program, where FSI focused on the vehicle hardware and its associated low level subsystem software, TSI focused on the user interface, and AUSI focused on program management and the development of the onboard high level mission/system software. In this manner, a diverse set of talents was brought together to realize the SAUV II design.

This paper will describe what we have named the SAUV “production” architecture, which has evolved during the past two and a half years. It will describe the various software modules and identify the functional components of the system that are controlled by the high level vehicle software. The paper will also describe the insights that resulted from in water testing and the impact that those insights have had on the overall system architecture.

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THE IMPACT OF POWER SYSTEM TYPE AND VEHICLE SIZE ON RANGE AND PAYLOAD FOR UUV’S

August 24, 2003
Hughes T, THE IMPACT OF POWER SYSTEM TYPE AND VEHICLE SIZE ON RANGE AND PAYLOAD FOR UUV’S, UUST, 24 Aug 2003

This paper reviews the status and projected performance of various power system types, including batteries, fuel cells, and hydrocarbon and liquid-metal-fueled heat engines and examines the relationship between power system type and vehicle diameter on achieved range and payload.

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Solar Powered Autonomous Vehicle Development

August 24, 2003
Jalbert J, Baker J, Duchesney J, Dalton W, Nitzel R, Holappa K, Solar powered autonomous Underwater Vehicle Development, UUST, Aug 24, 2003

To meet the rapidly expanding requirements for Autonomous Underwater Vehicles (AUVs), Falmouth Scientific, Inc. (FSI) is working in cooperation with the Autonomous Undersea Systems Institute (AUSI) and Technology
Systems Inc. (TSI) to develop a vehicle capable of long-term deployment and station-keeping duties. It has long been considered that AUV platforms, in-principle, could provide an effective solution for surveillance (security and
anti-terrorist), environmental monitoring and data portal (to sub-sea instruments) requirements, but limitations in battery life have limited AUV usefulness in such applications. The concept of a vehicle that would allow on-station recharging of batteries, using solar cells, has been presented as a means to significantly enhance the effectiveness of AUV platforms where long-term or ongoing deployment is required.

The Solar Powered AUV (SAUV) is designed for continuous deployment (weeks to months) without requirement for recovery for service, maintenance or recharging. The SAUV under development is designed as a multi-mission
platform to allow payload configuration by the end-user to optimize the SAUV for coastal/harbor monitoring, data portal (to moored sub-surface instruments) applications, or any other application where long-term deployment is
required. The SAUV is designed to reside on the surface while recharging batteries and then to execute its programmed mission. While on the surface the SAUV is designed to communicate via Iridium® satellite or RF communications link to upload collected data and to allow reprogramming of mission profiles.

Development of the SAUV has generated numerous engineering challenges in design of the solar recharge system, design of a propulsion/direction control system capable of handling the unique shape requirement, design of the telemetry system, and development of mission control algorithms that include surfacing and battery recharge requirements.

This paper discusses the details of unique SAUV design requirements, specific engineering solutions for hull, panel, battery, communication, charge control, navigation,

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Multi-UUV Missions Using Ranger MicroUUVs

August 24, 2003
Schultz B, Hobson B, Kemp M, Meyer J, Moody R, Pinnix H, St. Clair M, Multi-UUV missions Using Ranger MicroUUV's, UUST 2003, Aug 24, 2003

Groups of four UUVs have been used to validate a plume source localization algorithm and map the 3-D movement of a salinity front over time. These missions have demonstrated that not only are multi-vehicle deployments possible, but by using teams of cooperating vehicles, difficult tasks such as plume source localization can be performed quickly and that small volumes of the ocean can be simultaneously sampled with unprecedented spatial and temporal resolution.

The key to the success of these missions is the small, inexpensive and easy tooperate Ranger MicroUUV from Nekton Research. We report on the results of recent multi-agent missions and provide information about the UUVs used during these missions.

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Experirences on actuator fault detection, Diagnosis and Accomodation for ROV's,

August 27, 2001
Caccia M, Bono R, Bruzzone Ga, Bruzzone Gi, Spirandelli E, Veruggio G, Experirences on actuator fault detection, Diagnosis and Accomodation for ROV's, UUST-12, Aug 27 2001

Abstract
This paper addresses the problem of low cost actuator fault detection, diagnosis and accommodation for Remotely Operated Vehicles. The research is based on the analysis of the telemetry of Romeo, the overactuated ROV developed by C.N.R.-I.A.N., operating both in nominal and different failure conditions. Results demonstrate how the monitoring of the servoamplifiers' I/O variables enables the detection and diagnosis of actuator faults for operating ROVs, supporting the pilot in making decisions on the realtime reconfiguration of the propulsion system. The integration of the servo-level FDDA module with a conventional navigation, guidance and control system is discussed. On the basis of experienced time-varying effects of operating failures, suitable models of the damaged actuators and algorithms for the generation of fault symptoms and alarms have been designed, implemented and satisfactorily tested on a large
amount of recorded ROV data. The conventional fault accommodation procedure based on the reconfiguration
of the vehicle's thrust control matrix has been applied. The capability of Romeo of working in a reduced actuation configuration has been operationally demonstrated executing shallow water benthic missions for scientific users.

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AUV bloopers or why Murphy must have been an optimist: A practical look at achieving mission level reliability in an AUV

August 20, 1999
AUV bloopers or why Murphy must have been an optimist: A practical look at achieving mission level reliability in an AUV

Autonomous underwater vehicle technology continues to advance at a rapid pace. REMUS (Remote Environmental Monitoring UnitS), developed by the Oceanographic Systems Laboratory at the Woods Hole Oceanographic Institution, is one of the most widely used autonomous underwater vehicles in the world. Each year REMUS vehicles participate in numerous field exercises in support of scientific and navy research objectives. Designed for coastal operations, REMUS is normally deployed with a CTD, light scattering sensor, side scan sonar and an up-and-down looking acoustic doppler current profiler (ADCP). Additional sensors are easily integrated in the vehicle and a bioluminescence instrument and a turbulence sensor package. Recent development efforts have improved the REMUS vehicle overall design and performance, and include integration of two new sensors. Vehicle improvements include lower drag, a new propulsion, new lithium-ion batteries and a new external interface. Maximum speed has been increased from 1.75 m/s to almost 3 m/s (6 knots) and mission length has increased to 22 hours at the 1.5 m/s (3 knots) cruising speed. REMUS has been used to demonstrate a new autonomous underwater vehicle application: plume mapping. A rhodamine fluorometer was installed to map a plume on a steep sloping sea floor. Results from the field test demonstrate the effectiveness of an AUV as a tool in this task. A second REMUS vehicle has been deployed with an optical sensor package. The instruments in the package include a chlorophyll fluorometer and up-and-down looking, seven channel radiometers. This package combined with the standard CTD and ADCP generates a significant scientific data set, which supports both physical and biological oceanographic research

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Open Ocean Operational Experience with the AUTOSUB-1 Autonomous Underwater Vehicle

August 1, 1999
Griffiths G, Stevenson P, Webb A, Millard N, McPhail S, Pebody M, Perrett J, Open Ocean Operational Experience with the AUTOSUB-1 Autonomous Underwater Vehicle, UUST, Aug 01 1999

Abstract
The Autosub-la autonomous underwater vehicle (AUV) designed, built and operated by the Southampton Oceanography Centre is a medium endurance, multipurpose sensor platform designed for marine science studies of the upper ocean. With a specified range of 250 km, operating at 3.8 kt, and a diving depth capability of 500 m the vehicle has completed 179 engineering and science missions in UK coastal waters, off the east coast of Florida and off Bermuda. This paper focuses on three key areas particularly important to AUVs operatingo n long missions in the deep or open ocean: the predictability of the primary cell energy supply, particularly its predictability; buoyancy changes in a vehicle without active buoyancy control and scientific sensor performance - the raison d’2tre for the vehicle. We draw upon the methods, observations and results from the 1998 Autonomous Vehicle Validation Experiment (AVVEX)
when Autosub- 1 a operated off Bermuda in August-September 1998.

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