Kongsberg Simrad's Hugin
The Hugin project was started in 1995 as a cooperative development between Statoil, Norwegian Defence Research Establishment, NUI, and Kongsberg Simrad. The ojective was to develop a free-swimming vehicle for high-resoloution seabed mapping and imaging. The original Hugin vehicles were used in several tests, scientific, and commercial pipline route survey operations.

Today's Hugin 3000, current flagship AUV of Louisiana survey contractor C & C Technologies, represents further development towards deeper waters and an extended payload suite. The 3000 designation represents the AUV's depth-rating of 3,000m, or 10,000 feet.

The Hugin utilizes Kongsberg Simrad's HIPAP 500 system for continous update of position. The Stinger launch system works in sea state 5. The 50-hour endurance time is made possible by a aluminum/oxygen semi fuel cell battery. Used liquids are recycled into industrial soap.

The Hugin is a cost-effective tool for seabed surveying, but can also tackle other applications, including oceanographic resarch, resource monitoring, environmental monitoring, and military defense tasks. For commercial seabed mapping and oil pipline surveying, data quality control and highly accurate positioning is crucial. To meet these requirements, Hugin uses a high-speed unidirectional acoustic data link to provide decimated data samples in real time. Continous position updates are given by the HIPAP 500 acoustic super short baseline system to ensure position accuracy.

For naval applications, the Hugin has been tested by the Norwegian Defence Research Establishment. A number of dummy mines were lowered to the seabed at depths ranging from 260 to 650 feet (80 to 200m). The Hugin made runs over the dummy minefield at altitudes of 30 to 100 feet (9 to 30m). The resulting EM 3000 images clearly showed the dummy mines. From the backscatter data (bottom image), even the recovery chain running from the mines gave a significanly stronger echo than the surounding seafloor.

And in December 2001, Kongsberg Simrad, the Norwegian Defence Research Establishment, and the Royal Norwegian Navy demonstrated a variety of military applications, including seabed mapping, route survey, rapid environmental assesment, autonomous forward mine hunting, and covert mine hunting. Visit www.kongsberg-simrad.com.

C & C's Hugin Heads to the Mediterranean
C & C Technologies' R/V Rig Supporter left the Gulf of Mexico for the Mediterranean Sea on May 18, 2002. The Rig Supporter is a 260-foot research vessel equipped with the Hugin 3000 AUV system. C & C began a surveying a pipeline project in the Mediterranean Sea at the end of June. Other interested clients in the region are encouraged to contact C & C to explore the cost savings of this proven technology. C & C's Hugin is outfitted with multibeam swath high-resolution bathymetry and imagery, chirp sidescan sonar and sub-bottom profiler, C-Nav differential GPS integrated with acoustic/inertial navigation, and acoustic communications. The system also includes a proven high seas launch and retrieval system (LARS) and is stored in two containers that can be air freighted anywhere in the world.

During the last year, C & C's AUV completed more than 10,000km of surveys, including regional mapping programs at BP International's Crazy Horse, Mad Dog, Holstein, and Atlantis developments. The Hugin's pipeline hazard projects included Shell's Glider and BP's Mardi Gras and Green Canyon pipeline systems. Other clients have included Mariner Energy, Samedan Oil, Burlington Resources, Kerr-McGee, BHP Petroleum, Williams Field Services, TotalFinaElf, Global Industries, El Paso Productions, and the Minerals Management Service.

Hydroid's Remus
The Remus is a lightweight, low-cost AUV designed by the Woods Hole Oceanographic Institute (WHOI) of Massachusetts. After five years of development, the vehicle has finally moved out of the Institute and into the commercial world of Hydroid, Inc., located in East Falmouth, Mass.

Hydroid, which was established by the original inventors of the Remus system, has an exclusive license agreement with WHOI which gives them full rights to the Remus vehicle technology. Hydroid is now driving Remus to the next level, providing leading edge product advancement, customer service, and support designed to meet the stringent demands of the commercial marketplace.

Remus's small size, high-quality data, and ease of operation appeal to a wide array of users, and have resulted in countless hours of vehicle operation for key applications such as environmental monitoring, mine counter measures, and hydrographic surveys. Because the Remus weighs less than 80 pounds, launch and recovery are simplified and operational expenses reduced. Special handling equipment is not required, and overnight shipping via commercial carrier is possible.

Despite its small size, the system can operate to depths of 330 feet (100m). The system can be deployed for up to 22 hours at an optimal speed of three knots, and for up to eight hours at five knots.

Hydroid recently placed an order with RD Instruments for 10 RDI Workhorse Navigator-based Doppler Velocity Logs/Acoustic Doppler Current Profilers. The specially-designed units provide ADCP data, as well as fast and precise vehicle navigation updates. The order is for both four-beam and eight-beam systems, which provide a powerful combination of sensors in a compact package for ROV, AUV, or towed fish navigation and control. RDI's DVL/ADCP, designed specifically for the Remus vehicle, provides acoustic Doppler current profiling (ADCP) capability, as well as measurement of 3D bottom track, water-referenced vehicle velocity, and altitude.

The Remus AUV also carries an impressive and powerful suite of standard sensors, including a Marine Sonic Technology sidescan sonar, a CTD with YSI, FSI, and Ocean Sensors integrated, and a Wetlabs light scattering sensor. Many other instruments can also be integrated, including a fluorometer, bioluminecense sensor, radiometer, acoustic modem, Sontek acoustic Doppler velocimeter, and Imagenex altimeter. New sensors are continually being added, including a plankton pump, a video plankton recorder, and an electronic still camera.

Remus's navigation system is comprised of a combination of a Long Base Line (LBL), Ultra Short Baseline (USBL), and Doppler Velocity Log (DVL), ensuring precision vehicle tracking and mission accuracy. The system uses a Windows-based laptop computer, with an intuitive user interface that allows anyone to operate Remus with just a few hours of training. The simplicity is evident in terms of its ease of mission programming, operation, recovery, and data download, and analysis. Built-in tools allow the data to be accessed, plotted, and posted to the Internet within minutes of recovery.

Routine vehicle maintenance consists of washing it down and recharging the batteries, which does not require opening the housing, but merely plugging in a cable and pressing a button. This low level of general maintenance and intervention results in reduced opportunity for error and greatly improved system reliability. For more, visit www.hydroidinc.com.

Yardney AUV Batteries
Yardney silver-zinc batteries have been utilized by both military and commercial submersibles and AUV systems. The silver-zinc battery's inherently high energy density and power density levels extend the vehicle's range of performance, improve reliability, and can effectively reduce power cost.

This rechargeable battery couple can provide high current at a nearly constant voltage over much of the required discharge and up to five times greater energy per unit mass and volume than the comparable lead acid and nickel cadmium batteries. Silver-zinc batteries can be provided as pressure compensated units or can be contained in a pressure hull or uncompensated battery compartment.

In typical AUV applications, the critical profit parameter is the dollar-per-hour of work performed while submerged. Silver-zinc batteries can actually reduce this cost in some applications. The actual run time of a silver-zinc battery as compared to a lead-acid battery is easily three times greater. This would equate to three times the overall distance covered while submerged. Cost savings would calculate out at one-third the cost-per-hour submerged using silver-zinc.

Although the initial cost of these silver batteries is greater than other battery systems, the silver-zinc battery offers the highest energy density in watt hours per pound and watt hours per cubic inch, and more importantly, power density in watts per pound and watts per cubic inch of any AUV battery presently used.

Another misunderstood cost factor of significance to AUV contractors is that the silver in these cells is actually reclaimable. The salvage value of the silver from expended silver cells can reduce the overall cost required in subsequent purchases or result in a cash rebate.

Another method to reduce battery cost on government-sponsored programs is to have the US government supply the silver required. Thus, the cost to the program is reduced and the government recycles the batteries for reuse.

The fact that silver-zinc batteries are initially more expensive, sensitive to overcharge, and have a shorter cycle life than most secondary batteries has limited their use to applications where space, weight, and vehicle run time are prime considerations. However, Yardney silver-zinc batteries have been produced in which over 100 cycles over a period of 24 months have been achieved. Standard silver-zinc cell models are available in prismatic from one-ampere-hour to over 1, 100 ampere-hours. Each cell model is supplied with its specific fill kit and intercell connector to simplify operations. Cells can be arranged in a variety of configurations to meet almost any complex shape, yielding AUV manufacturers maximum design flexibility.

When battery containers are necessary, cells can be installed in fiberglass, stainless steel, titanium, aluminum or other suitable battery cases to meet specific environmental and mechanical stress conditions.

The US Navy has utilized Yardney's silver-zinc batteries in may of their active submersible vehicles. Commercial AUV companies currently using Yardney silver-zinc cells and batteries include ISE, MIT Sea Grant, BlueFin Robotics, Boeing, and Northrop Grumman.

LinkQuest's Acoustic AUV Modems
LinkQuest's high-speed acoustic modems have made impressive contributions to the success of commercial surveys conducted by C & C Technologies' Hugin 3000 AUV.

Using an acoustic modem to monitor status of an AUV and upload images from sensors continuously is uncharted territory. Nevertheless, LinkQuest 4010 deepwater modems performed flawlessly after initial fine tuning and modification, thanks to the technical expertise and cooperation from C & C Technologies and Konsberg Simrad. Simultaneous real-time monitoring of AUV multibeam, sidescan sonar, and sub-bottom profiler has proven to be very beneficial from a quality assurance standpoint. This allows real-time adjustments to be made, such as changing swath width, AUV height, pulse length, or route.

"We are pleased with the overall performance of LinkQuest' modems, " says C & C's Phil Devall. "Our client is very impressed with our data presentation because of the ability to retrieve data acoustically made possible through LinkQuest's modems."

In the past year, over five gigabytes of data has been uploaded in real time during commercial deepwater AUV surveys. This makes the LinkQuest 4010 high speed modem the only AUV data link modem on the market with long term robust field performance under extremely heavy data usage.

For more information, visit www.link-quest.com.

The HS Autosub
The HS Autosub, from Subsea 7 (a new company formed by the merger between Halliburton Subsea and DSND), addresses the demands of commercial surveying and positioning in ever deeper waters. The starting point was a 10-year license agreement with Southampton Oceanographic Centre for its Autosub technology, already a well-established research tool.

Initially, HS Autosub will focus on site, pipeline, and cable route surveys. Subsea 7 then expects that the navigation systems will be further refined to allow acoustic pipeline inspection using high frequency sidescan sonar, and subsequently, digital video acquisition. Intervention capabilities are a long-range goal.

The vehicle is rated to 10,000 feet (3,000m). The power source gives a deployment time of at least 24 hours, including a generous safety factor. Dimensions are 22 feet long by 36 inches diameter. At a weight of 5, 300 pounds, the large vehicle is a superb platform for deploying a comprehensive suite of survey sensors.

The vehicle divides into three sections. The nose section contains navigation and other core and mission orientated equipment. A central section houses the batteries and electronics. The vehicle is suspended from the central section during launch and recovery operations. Finally, a tail section incorporates the propulsion and control surfaces.

It is important that an AUV has a system for recovery from depth in the event of a system or power failure. This requirement led to the adoption of a simple electromagnet holding a 20kg weight, which is dropped if any of the predetermined failure conditions are met. This action renders the AUV positively buoyant, thus enabling it to rise to the surface. The release system has been specifically designed so that power consumption in stand-by mode is kept to a minimum.

The HS Autosub has completed significant levels of testing, including inshore trials of acoustic sensors, which have demonstrated that potential problems of acoustic interference have been overcome. The final inshore trials of the complete system are imminent, prior to the vehicle undertaking its first offshore campaign.

Thales's Sea Oracle
Thales GeoSolutions' fleet of eight survey AUVs reached a significant milestone with the recent factory acceptance test of the first of the series. This first Sea Oracle vehicle is now undergoing sea acceptance tests, while the second vehicle was expected to have completed its factory acceptance test by the time this is published. The vehicles will be operated in pairs and include a purpose-built integrated launch and recovery system and maintenance van. In addition to completing the tests, the vehicles have received ITAR approval for export to all major deepwater oil producing areas.

The Sea Oracle AUVs are based on a third-generation design and have been optimized during the design stage for survey. They consist of a nose section containing batteries and an obstacle avoidance sonar, a midsection containing the survey sensors, and a tail section containing the navigation system, propulsion system, and main computer. The midsection may be removed and replaced with one containing different sensors to facilitate mission flexibility. The vehicle is just over 11 feet long and 21 inches in diameter, with a weight of only 1, 170 pounds, to make the system easy to launch, recover, transport, and operate.

The Thales AUV's onboard data collection system represents a step in sensor integration. The system is based around a Reson 7100 multibeam echo sounder, incorporating a 53cm conformal sonar receiver designed to provide the smallest beam width possible for the system. The transmitter may be varied between 100kHz and 200kHz to allow for reconnaissance and high-resolution surveys. The receiver is solid state and requires no pressure housing, making it very efficient for AUV operation. It is mechanically rigid and forms part of the vehicle's structure when installed. The sensor suite also includes an Edgetech integrated chirp sidescan sonar and sub-bottom profiler. All of the dry electronics, along with the data collection system, are incorporated into a positively-buoyant titanium pressure vessel.

The navigation system consists of a Litton LN-250 fiber optic inertial navigation system integrated with an RDI Doppler velocity log and a Digiquartz pressure sensor. A Sonardyne AVTrack beacon is fitted on the vehicle to provide absolute position updates via a USBL system on the ship. The battery is from Bluefin Robotics and provides power for a 20-hour survey, with four hours for descent, ascent and recovery. The battery changing and charging system is integrated into the maintenance van to provide quick turnaround.

The Thales Sea Oracle is designed to operate efficiently over a wide range of depths with a maximum operational limit of 10,000 feet (3,000m). The planned survey speed is three knots, which will give about 100km of coverage per vehicle, per day.

Maridan Pushes the Envelope
A Maridan AUV recently completed an oceanographic survey mission under the ice in the Greenland Sea. Maridan Survey, the company's survey contracting division, carried out the survey for a group of European oceanographic organizations under the Convection Project funded by the European Commission. The purpose of the mission was to gather data from a convection area known to scientists as "the cold heart of the Oceans."

The Greenland Sea expedition, headed by Professor Peter Wadhams of the Scott Polar Research Institute in Cambridge, managed to locate the convection area. The Norwegian research ship, Lance, launched the Maridan AUV to study the physical processes that drive the sinking process.

On each mission, the vehicle (known as Martin) was programmed to travel to a range of 1km under the ice, measuring temperature, salinity and currents, before returning to the research ship with its stored data. During the missions the AUV was also preprogrammed to scan the underside of the ice using its upward-looking side scan sonar.

After the expedition, Prof. Wadhams said, "The Maridan AUV performed very well in arctic conditions. Despite the weather, it managed to provide new important data for analysis of the convection process. This is also the first time that sonar data of the ice underside has been obtained by an AUV in the Arctic. Previously we were dependent on military submarines."

The North Atlantic convection area is the origin for a process taking place every winter whereby a characteristic ice formation called "pancake ice" is generated at the surface, accompanied by intense cooling. An important result of this air-sea interaction in the convection area is an increase in ocean surface salinity and density that allows the water to sink to great depths. Since the resulting circulation provides global-scale transport of heat and salt, scientists are keenly interested in examining this Arctic convection process. By analyzing the data collected by the Maridan AUV, the scientists hope for better understanding and prediction of climate changes in Northern Europe and Scandinavia.

Under-ice missions continue to be one of the major challenges for AUV operations. By successfully completing the Greenland survey, Maridan acquired valuable experience and underlined its position as a player to be reckoned with in the AUV game.

To further this reputation, Maridan Survey recently arrived in the Gulf of Mexico with the aim of introducing the offshore community to the advantages of using AUVs. Proven in operation during this spring, the Maridan AUV has performed Gulf surveys for BP that leave no doubt about the advantages of the AUVs.

Close platform surveys will lead to what the company considers its next big growth area - abandonment of sites and structures. With the AUV, clients could have a quickly mobilized tool for doing the surveys to take care of government requirements.

The Gulf of Mexico is a spider web of pipelines of all sizes. Pipelines are vulnerable to the forces of both nature and trade. In response to this problem, Maridan is currently working with Heriot Watt University and Innovatum to construct an Autotracker application that will allow for autonomous tracking of pipelines. The project is scheduled to be tested in the North Sea this fall.

Johannes Christensen, Maridan CEO, says, "We expect a lot from the system. It will be one of the first systems on an AUV in commercial operation to really widen the horizon for AUV applications.

Furthermore, the autonomous operations of the AUV will be even more significant since the system itself with locate and track the pipelines. At the same time, we will not compromise our data quality."

The French Connection: Cybernetix
Cybernetix, based in Marseille, France, is committed to providing the offshore industry with innovative solutions for deep and ultra-deepwater intervention, repair and maintenance tasks - unlike most other manufacturers, whose AUVs are aimed at survey or data collection. Cybernetix believes that the best way to go deeper is not necessarily to lengthen ROV umbilicals, and this is reflected in the company's attitude toward what an AUV can do.

One of the company's key abilities is its development of advanced telerobotic systems, particularly for use in hostile environments. Its Offshore Division integrates these developments into its autonomous and remotely operated vehicles. The company's range of vehicles can provide a complete "care package" for offshore Floating Production Systems (FPS).

In October 2001, successful offshore trials were carried out with Swimmer, an AUV/ROV hybrid vehicle that Cybernetix refers to as an "HUV." Once launched from the FPS or oil platform, Swimmer carries a work class ROV to designated docking stations. Once docked, wet-mateable connectors provide power, data, and communications that allow the ROV to be flown out of the shuttle (via on-board TMS) to perform its intervention task under the control of an operator on an FPS or distant platform. This removes the necessity of having a costly DP ROV-support vessel in attendance.

Once the task is completed, the ROV returns to the shuttle, which has meanwhile had its batteries recharged and received instructions for the next location, to which it then proceeds autonomously to repeat the process. The company envisions that the complete HUV will eventually be capable of remaining indefinitely submerged and be recovered only for repairs and maintenance. The current vehicle is rated to 10,000 feet (3,000m), but can be developed to go deeper if needed.

Cybernetix's Autonomous Light Intervention Vehicle (Alive) is currently under development and scheduled to be operational in late 2003. It addresses the issue of economically carrying out light intervention tasks (photographing/filming, turning a valve, etc.) on structures whose shape and construction is known.

Alive can be launched from any suitable vessel of opportunity and proceeds autonomously or under control from the surface operator (via acoustic modem) to a pre-designated point some 30 feet away from the work site. Once there, it stabilizes its position and onboard sonar and video units lock onto and appraise the structure. It then proceeds to the structure and latches on using a dedicated 5-function manipulator, sending back images to the surface via acoustic modem. Its other full-function manipulator (or cameras) carry out the required task using a series of internal pre-programmed commands triggered and validated by the surface operator, again via acoustic modem - this removes the problem of the inevitable delay caused by the speed of sound through water. Once the task is completed, Alive returns to the surface and is recovered - again, no need for a support vessel.

The Spider is a tracked autonomous vehicle developed by Cybernetix for monitoring pipeline touchdown during construction, and for carrying out pipeline inspection using sonar and video mounted at the end of its 21-foot telescopic boom. Equipment such as sub-bottom profilers can also be mounted on the body itself. Having tracks rather than thrusters makes position keeping in strong currents very easy. The vehicle can send images back to the surface via acoustic modem, plus store data onboard, either by operator control via acoustic modem or via fiber optic umbilical when real-time imaging is required.

Cybernetix is repesented in the US by Technosphere. For more, visit them online at www.t-sphere.com.

Nekton Research Multi-Vehicle Approach
Nekton Research is developing a low-cost, multi-AUV search and data acquisition system for 3D searches and data collection with high spatial and temporal resolution.

Nekton's system features a school of 10 micro-AUVs, each equipped with a multi-parameter water sensor array, a novel set of distributed control algorithms, and a cutting-edge acoustic communication and navigation system. This multi-vehicle approach will open the door to numerous new applications, including air-deployed search and localization of lost assets, source localization of chemical plumes, visualization of small-scale mixing dynamics, and 3D flow dynamics.

The development project, funded by the US Defense Advanced Research Projects Agency (DARPA), is a collaboration between Nekton Research, Woods Hole Oceanographic Institute, and Sandia National Laboratories. WHOI is developing the multi-user, passive LBL acoustic navigation and communication system. Sandia is contributing a set of multi-agent search algorithms, and Nekton is responsible for the vehicle development, system integration, and system operation.

The system' parameters are that the vehicles must be extremely reliable, easy to operate by a single pilot, and inexpensive. The strength of the system lies in the simultaneous acquisition of parallel steams of data from 10 different vehicle paths, despite the fact that individual vehicles have a relatively low sensor payload.

In its most basic configuration, this parallel deployment will significantly reduce data collection time. In more sophisticated missions, vehicles will be able to work collaboratively by sharing sensor readings that could be used to change a vehicle's mission on-the-fly. This adaptive mission re-planning should allow a school of AUVs to trace a faint chemical signal in a plume back to its source. Some examples of chemical plumes could be effluent from a weapons processing plant, a downed aircraft, leaking pipeline, fresh water spring, or black smoker vent.

While these micro-AUVs are available today, offshore operations with more than three vehicles are not yet a reality. The first inshore deployment of 10 micro-AUVs is planned for August 2002, with offshore missions planned for some time in 2003.

Each vehicle features a 3.5-inch diameter by 35-inch long hull rated to 330 feet (100m). They can cruise at two knots for five hours using a 172W/hr lithium-ion battery pack. A plug-and-play multi-parameter water sensor array is fitted with conductivity, temperature, depth and dissolved oxygen as standard sensors with pH, chlorophyll, turbidity, nitrogen, ammonia available as options. Sidescan sonar, methane, and TNT detectors are in development. Given the rate at which sensors are being miniaturized, Nekton expects the list of sensors available for micro-AUVs to quickly grow.

Micro-AUVs will never replace large AUVs for many tasks offshore, but their low cost, ease of deployment and reliability should prove to be valuable assets as offshore contractors look for ways to perform existing and future tasks more efficiently.

JW Fishers' Mini-AUV
Another mini-AUV now on the market is JW Fishers' Pipe Inspection Camera (PIC-1), a patented underwater camera system capable of performing long internal pipeline inspections. This AUV system is completely self-contained, with video camera, underwater lighting, batteries, and a computer control system.

Using natural water flow for propulsion, the AUV's streamlined design and unique ballast system enable it to travel down the center of the pipe. With a water flow speed of two feet per second, a 2.7 mile pipe can be videotaped in a single trip.

By changing the operator-adjustable ballast point on the housing, the camera can be positioned to look at either the top or bottom half of the pipe. With an optional rear-mounted camera, both top and bottom can be videotaped simultaneously. The underwater lights provide the necessary illumination for a clear, high-resolution picture.