Commander, Naval Meteorology and foler-¥-laveyele-] lin mereliiliit-lare) Stennis Space Center, MS 39522-5001 Technical Report (TR 01001) . February 2001 REVIEW OF A AUTC UNDERWATER VEHICLE (AUV) DEVELOPMENTS > dangles aie ae Bais ate ie ES oy Meare aunind SPANO E Bete (So Seale ice H Recess menomiuienasticaite massage Ae aicebansemunsenanenaee™ Review of Autonomous Undersea Vehicle (AUV) Developments FOREWORD A maturing Autonomous Underwater Vehicle (AUV) technology currently offers a wide range of applications, for both commercial and military sectors. The Naval Meteorology and Oceanography Command (NAVMETOCCOM), in coordination with the US Navy AUV program, has specific plans for the use of AUVs to augment the NAVMETOCCOM fleet of ocean survey ships. In support of those plans NAVMETOCCOM, the Office of Naval Research and the Naval Research Laboratory have partnered with commercial and academic developers and have provided a test range with exercise opportunities to facilitate AUV technology developments. As a result of those efforts, NAVMETOCCOM is in the process of fielding its first AUV for operational ocean survey. This report was commissioned to provide a snapshot of the current state of AUV technology, with emphasis on the area we consider is the greatest limiting factor — power sources. We owe a special acknowledgement for the contributions of RADM J. Brad Mooney, USN (Ret), who continues a career dedicated to advancing research and development for naval submersibles. T. Q. Donaldson V RDML, U. S. Navy Commander, Naval Meteorology and Oceanography Command \\ Wh. yor’ uw IN\\=) 9030" Review of Autonomous Undersea Vehicle (AUV) Developments hic (nstitution | annic nsuiue! REPORT DOCUMENTATION PAGE teapones, inch.ding the time for ‘colection of réormation, Send comments B if HOR RADM Brad Mooney USN (Ret.), Anteon Corp. Donald Collins, Anteon Corp. Jerry Boatman, Naval Meteorology and Oceanography Command GANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER TR 318 10. SPONSORING/MONITORING AGENCY REPORT NUMBER Naval Meteorology and Oceanography Command ‘ 1100 Balch Blvd. Stennis Space Center, MS 39522 sieriianion is unlined This report provides developing plans to improve the mission capability of Commander, Naval Meteorology and Oceanography Command through the applications of AUVs. That mission is to collect, interpret, and apply global data and information for safety at sea, for strategic and tactical warfare, and for weapons systems design, development, and deployments. Underwater Vehicle (AUV), Unmanned Underwater Vehicle (UUV) 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATIO 19. SECURITY CLASSIFICATION OF REPORT OF THIS PAGE OF ABSTRACT UNCLASSIFED UNCLASSIFIED UNCLASSIFIED 14. SUB Autonomous Review of Autonomous Undersea Vehicle (AUV) Developments Table of Contents EXGClitiVecS UMIMANy «adcceccctevsnostenducteneteencasescagatis deachesuau chess ccetesanapncssdesaescGaas@esigustaeen cdyGi cat eloeeleamenase ts cusiee da xosaucenceican cayegbencios 1 HITROGU CHOI sevesescsicec Sacecivowscdcn5cmsedeaed onesies sedeeaiecaa iia su os ands savoarevbesauias uuu basins studi des tan ceveeaadueasuueiotiehdseetun casavumaneaiaadiafeuntareences 3 Environmental AWanemGSSi.2 xi. foc: Sec cennccaetceaccnscosaannasdens toxteeaaedseace dese etedces cawbzexeoseteatea and savivesdetcedec: saiicadves Vonncotecsreceseyeeeee 5 Tactical QOCCANOGlAEDMY ceccxccees ctv sxcetes ceaducsetccucnscecsasvaiec’ yoainc cx dabacenes teenies tieusacteaeee sce ves se eda tay ivesotete csi stanaactleectasis od x Hlement Element : Smart er eee Monokithic Distributed ensor Sande Meta-Sensor Figure 2. Sensor Technologies Development 17 Review of Autonomous Undersea Vehicle (AUV) Developments RESEARCH AND DEVELOPMENT FOR UUV SYSTEMS As the Navy shifts its focus from a global threat to a focus on regional challenges, it is developing the capabilities needed to execute successful operations in the complex "littoral environment." There is a need for cost-effective, unmanned, clandestine, undersea, off-board platforms with sensors that can serve in a wide variety of roles and missions, including mine warfare, surveillance, reconnaissance, intelligence collection, and tactical oceanography. To address these needs the Navy, led by Office of Naval Research (ONR) sponsorship, has coordinated research and development efforts. ONR has helped lay the foundation through active sponsorship of a wide range of academic initiatives. In partnership with the Naval Oceanographic Office, ONR hosts annual exercises of AUV/UUVs in their Gulf of Mexico UUV test range. The UUV demonstrations, called "AUV Fest," provide opportunities for academic institutions and industry to showcase their UUVs. ONR also uses the event to evaluate technologies necessary to meet a concept of operations for schools of UUVs for ocean sampling and measurement. Participation has increased each year. The opportunity for "cross-pollination" among participating teams is significant. The Navy invites external observers aboard the mother ship to increase exposure to others interested in exploiting the technology. Observed advances in UUV technology each year is remarkable. This event serves the UUV community immensely in advancing the state-of-the-art and generating enthusiasm. Operators of UUVs have gained confidence in their vehicles during these at-sea events. The UUV competitions sponsored by the Autonomous Unmanned Vehicle Systems International organization similarly stimulate the UUV community. The Navy has initiated a strategic planning group to coordinate specific development and acquisition efforts begun by Navy Systems Laboratories. 18 Review of Autonomous Undersea Vehicle (AUV) Developments NEAR-TERM MINE RECONNAISSANCE SYSTEM (NMRS) [4,5,6] A significant portion of the Navy’s regional challenges relate to mine warfare in the "littoral environment." One mine warfare tool the Navy is developing and fielding is a system designed to conduct clandestine, remote, unmanned minefield reconnaissance from a submarine. The system under development is the Near-Term Mine Reconnaissance System (NMRS) under a "special category" acquisition program for Fleet delivery and use. The NMRS entered operational use by the Type Commander (TYCOM) in early Calendar Year 1998 and participated in Demonstration II of the Joint Countermine Advanced Concept Technology Demonstration (JCM ACTD). NMRS is being installed on various platforms, including the USS LOS ANGELES (SSN 688) Class attack submarines. The NMRS is a fiber-optic tethered vehicle that is equipped with side- scan sonar. The launch and recovery of the reconnaissance vehicle is via a torpedo tube. Figure 3. Clandestine Minefield Reconnaissance NMRS provides theater commanders with a near-term capability for conducting clandestine minefield reconnaissance from a submarine (figure 3). The UUV transits to an area to determine if littoral waters are seeded with mines, allowing theater commander to rapidly assess probability of mines in the area. A highly accurate NMRS survey precisely locates and classifies minelike objects, providing theater commander with detailed information used to estimate location of enemy-deployed mine defenses and unmined coastal areas. With this information the theater commanders can determine the need for further UUV sortie operations. The NMRS incorporates SSN 688 torpedo tube technology hosted on a recoverable UUV with multibeam, active search sonar, and side-scan classification sonar. The NMRS consists of two 19 Review of Autonomous Undersea Vehicle (AUV) Developments reusable UUVs; launch and recovery equipment, including a winch and drogues; and shipboard control, processing, and monitoring equipment. Each UUV is slightly shorter than an Mk 48 torpedo and is launched and recovered via a standard SSN 688-Class torpedo tube. The UUVs contain highly accurate sonar systems that can pinpoint and classify minelike objects. Batteries provide the power needed to propel the vehicle during its sortie and operate the on-board electronic systems. Vehicle status, position, and sonar data are continuously relayed back to the host SSN via a fiber-optic cable, thereby allowing continuous monitoring of the vehicle during sortie operations and real-time analysis of data to the SSN from potentially mined waters. The UUV is loaded backward into the SSN 688 torpedo tube. Once ship conditions are correct, the UUV backs out of the tube under its own power. Outside the SSN (but still coupled to it via a steel cable and drogue assembly), it is towed to its mission area. The UUV then releases from the drogue; fiber-optic cable begins to pay out from both the drogue and vehicle; and the UUV independently transits and conducts its mission. Should the fiber-optic cable break, the UUV is programmed to autonomously return to a pre-set rendezvous point for recovery by the SSN. When the mission is finished, the UUV will rendezvous and mate with the drogue. A winch located in the SSN torpedo room will then pull the complete combination back into the torpedo tube. A trained Navy cadre will be responsible for the operation and maintenance of the NMRS when deployed. Cadre members are responsible to prepare and conduct UUV sorties; monitor vehicle status during transit and operation; replenish the UUVs post-sortie; and compile analysis of mission data. The NMRS Prototype (figure 4) commenced its at-sea test period in March 1998 at the Dabob Bay Test Range in Keyport, Washington. A detailed series of tests assessing vehicle and drogue_ stability, hydrodynamic control, navigation, and sensor performance was performed. In June 1998, the Navy successfully demonstrated its NMRS during the JCM ACTD held under NATO auspices off Stephenville, Newfoundland. NMRS was part of a large- scale amphibious warfare exercise designed to showcase emerging shallow-water mine warfare technologies. Figure 4. NMRS Prototype During the ACTD demonstration, the NMRS conducted five mine reconnaissance and survey sorties both in deep-water areas, with depths greater than 200 feet, and in shallow water (less than 200 feet) with varying bottom types. Since NMRS is designed to operate from a submarine torpedo tube, new procedures were developed to support surface launch and recovery from the research vessel. Navy Cadre members constructed all sortie plans using available information provided about the area and anticipated threat. Ultimately, all tasks were successfully completed, and the NMRS logged more than ten hours of operational search time. Suspected minelike objects were reported using standard mine warfare messages after detailed reconstruction and review of sonar data from the sorties. 20 Review of Autonomous Undersea Vehicle (AUV) Developments LONG-TERM MINE RECONNAISSANCE SYSTEM (LMRS) [4,7,8] The Long-Term Mine Reconnaissance System (LMRS) is a clandestine mine reconnaissance system that employs UUVs that are capable of launch and recovery from LOS ANGELES (SSN 688) and VIRGINIA (SSN 774) class submarines. The LMRS will provide an early, rapid, accurate means of surveying potential mine fields in support of proposed amphibious operations, other battle group operations, and for safe ship transit around mined waters. Torpedo Tube L&R RF and Acoustic 2 Autonomous UUVs Communications Single Sortie Reach 75-120 nm : Forward Looking Total Area Coverage Rate 400-650 nm Scares Calan Area Coverage Rate 35-50 nm2/day bee. Multiple Sorties Figure 5. LMRS Concept The U.S. Navy's UUV program office recently announced the selection of a team headed by Boeing Inc. to proceed with detailed design of the Long-Term Mine Reconnaissance System (LMRS) (figure 5). Sonatech, Inc., of Santa Barbara, California, will be providing all of the acoustic subsystems for this portion of the LMRS program, which includes the advanced forward-looking and side-looking mine detection and classification sonars as well as the homing/docking and acoustic telemetry sonars. The LMRS is a sophisticated autonomous UUV 21 Review of Autonomous Undersea Vehicle (AUV) Developments system that will operate clandestinely from U.S. Navy nuclear submarines. It will be launched from a torpedo tube. The UUV will be recovered through the submarine's torpedo tubes via a mechanical arm that is housed in another tube. The LMRS consists of a self-propelled, 21-inch diameter autonomous UUV equipped with mine search and classification sonars for locating mine-like objects in a naval operational area of interest. The LMRS will provide an early, rapid, accurate means of surveying potential mine fields in support of proposed amphibious operations, other battle group operations, and safe ship transit around mined waters. 22 Review of Autonomous Undersea Vehicle (AUV) Developments MISSION RECONFIGURABLE UUV [3,4] In 1995, under the sponsorship of several federal agencies, the World Technology Evaluation Center (WTEC) of Loyola College in Baltimore, Maryland sent a group of experts to Russia to benchmark the non-military undersea technology of the Former Soviet Union. In Valdivostok, the group visited the Institute of Marine Technology Problems and observed a very large number of AUVs. Most of the AUVs had conducted operational missions to depths exceeding 20,000 feet. Funding and emphasis for this institute was due in large part to the U.S. operation to recover a sunken Soviet submarine in the Pacific (Operation Jennifer). Russia desired to know what the United States did and did not recover. These vehicles were for the most part reconfigurable and modular. The WTEC report resulting from this visit to the Institute influenced AUV construction in the United States. The value of modular, reconfigurable AUVs was recognized. The core of the Navy's UUV Master Plan is the development of modular UUV systems that can be readily configured to perform a variety of missions. With common functional modules and standardized internal interfaces, great flexibility and transition between systems can be achieved. This plan recommends standardizing on two module sizes: a small 6 to 12-inch- diameter module and a larger, nominally 21-inch-diameter module. The UUV Master Plan describes these two module standards as follows. The Mini-Modular UUV (M?UUV) will be fielded in various sizes based on the small undersea modules. These modules would provide the Comm/Nav Aid capability and augment the current SSN capability (figure 6). The first step in developing the M?UUV would be standardization of the module size and contents, with special attention paid to those capabilities needed by the vehicle system as a whole. As these standard modules are developed, payload modules will be developed on a parallel path, thus ensuring system compatibility. These payload modules will include specific packages such as oceanographic sensors, communications links, and navigation systems. In turn, they can provide building blocks for larger systems. Following the initial module development, UUVs that meet the requirements of the Comm/NAV aid mission can be fielded, possibly as early as FY2005. Later M?UUVs will form the core of the SWARM concept, providing a rapid mine reconnaissance capability by FY08 with a clearance capability to follow. As required, oceanographic and other missions enabled by the M?UUVs would follow. 23 Review of Autonomous Undersea Vehicle (AUV) Developments Figure 6. Submarine-Launched UUVs The Tactical Modular UUV (figure 6) would address the needs of the Maritime Reconnaissance and Submarine Track and Trail capabilities. As with the M?UUVs, the first step is the standardization of module size contents, with special attention paid to those capabilities needed by the vehicle system as a whole. As these modules are developed, the payload modules will be developed on a parallel path, ensuring system compatibility. Modules developed under the M?UUV program will also be considered for incorporation in the system. This approach can lead to an initial Maritime Reconnaissance Capability by FYO7. The Submarine Track and Trail capability is obviously more difficult to achieve; however, if the technology is pushed, an effective UUV capability can be fielded. Initial variants of the Submarine Track and Trail capability may be less autonomous, require closer coordination to U.S. Forces (both surface ship and submarine), and may be smaller than the systems of the Vision. As dedicated modules become established and UUV mission capabilities grow, more complex mission can be pursued. Eventually, the full Maritime Reconnaissance and Submarine Track and Trail Capability can be achieved, and perhaps, tactical engagement with missiles and/or weapons launched from UUVs can be explored. 24 Review of Autonomous Undersea Vehicle (AUV) Developments PHOENIX AUV [9,10] The Naval Postgraduate School (NAVPGSCOL) has designed and built two underwater vehicles, NAVPGSCOL AUV | and the Phoenix AUV. The Phoenix AUV is in the 2-meter vehicle class weighing approximately 400 pounds (wet) but operated neutrally buoyant. It has been used for many studies relating to the design of control system architectures. The Phoenix has been the experimental test-bed for development and evaluation of nonlinear and adaptive control of vehicle motion. It has supported experimental work in system identification and the development of physical modeling and visualization. Figures 7 and 8 are schematics for the Phoenix AUV, and table 6 lists its specifications. TCHICOMPASS ST725 SONAR wae: DOPPLER SONAR ST 1000 SONAR ST525 ALTIMETER DEPTH CELL TRANSDUCER HOW LEAK TURHO PROBE DETECTOR HOW LATERAL THRUSTER VERTICAL GYRO FIN SER ¥O (8) JAXIS RATE GYRO HOW VERTICAL THRUSTER COMPUTER POW ER 12 VOLT HATTERY @) SUPPLY (2) FOR COMPUTER MOTOR SERVO CONTROLLER (6) GESPAC CARD CAGE RADIOCOMN., DIVE TRACKER LINK SYSTEM QNX PENTIUM COMPUTER 1Z VOLT HATTERY @} STERN ¥ERTICAL FOR GYROS) HOTORS THRUSTER FREE GYRO FREE GYRO ; POWER SUPPLY GPS UNIT STERN LATERAL THRUSTER REAR LEAK DETECTOR REARSCREW WOTOR (2) REARSCREW (2) CONTROL FINS (8) oh Dewrn B70. Mews 96 Ruy. 10-30-97? SCREW SHROUD @) Figure 7. Phoenix AUV for Mine Reconnaissance/Neutralization in Very Shallow Water Review of Autonomous Undersea Vehicle (AUV) Developments Table 6. Phoenix Specifications Length 7 feet Breadth 1.5 feet Displacement approximately 450 Ibs Top Speed knots Maneuvering 0 - 3 knots, Phoenix has vertical and horizontal cross-body thrusters, enabling it to hover. Depth Used for shallow-water application in depths less than 30 feet Mission 3 hrs using lead-acid batteries Duration Propulsion twin screw, one 1/4 hp brushless DC motor on each shaft PC-104 board with a pentium node running QNX. There is an ethernet module for network communications between internal vehicle processors and external computers. This is accomplished by either an Ethernet & Starlan Data Link or by a 900-MHz radio modem. Vehicle Control GESPAC Computer System running OS-9 real-time operating system - magnetic compass Navigation - Precision Nav - INS - Sistron and Donner motion package - Depth Cell, Psi-Tronix Inc., model S11-131 - DiveTracker, a short baseline acoustic positioning system by Desert Star Systems. - Scanning Sonar - Profiling Sonar - Doppler - Altimeter - ADCP Employment Phoenix is an experimental vehicle used for proof of concept. Vehicle may be deployed at any boat landing via trailer and is also capable of being lifted and launched from a pier or boat. System Control Sensors Deployment The AUV Center at NAVPGSCOL began in 1987 with the joining of interested faculty from the Departments of Mechanical Engineering, Computer Science, and Electrical and Computer Engineering. Instrumental in its formation was the Navy's interest in such vehicles for clandestine mine countermeasures work. While that is still of great interest to the Navy, other applications to Ocean Science and commercial usage for monitoring and surveillance have grown. The Center is focused on the development of advanced control methodologies for using this type of vehicle in very shallow waters, where persistent wave and current action from the seaway make operations difficult. The AUV Center has been funded for several projects by the National Science Foundation and ONR, and works collaboratively with the Florida Atlantic University. Other related work using multiple small robotic land vehicles for minefield clearance and missions clearing unexploded ordnance (UXO) has been funded by the Naval Explosive Ordinance Disposal (EOD) Technical Division (Indian Head). 26 Review of Autonomous Undersea Vehicle (AUV) Developments 7 RADIO COMMIETHERNET f ANTENNA (PILED 4 TO HULL OR FLOATING) FIN ~N 0 CR et eee ene ne ttc c ccm GIS ANTENNA DIVE TRACKER TRANSYDLCER —— _ 81725 YONAR DRAIN PLLG Y'18808 SONAR “— DOPPLERYONAR SIDE VIEW \— ILRBO PROKE DIFFERENTIAL SCREW SHROL DY — GUYS ANTENNA ——_ \ 7— ETHERNET FORT Va / fF wean semcws OHA CUSTER L_ ACCESS HATCH TOP VIEW OrevoB) BD. Nan’ Figure 8. Phoenix AUV —- External View 27 Review of Autonomous Undersea Vehicle (AUV) Developments ADVANCED UNMANNED SEARCH SYSTEM (AUSS) [1,11,12,13,14] The Ocean Engineering Division at the Naval Command Control and Ocean Surveillance Center Research, Development, Test and Evaluation Division (Naval Research and Development (NraD)) has developed and fielded two successive un-tethered, supervisory-controlled UUV systems: a prototype and an improved model. These robotic vehicle systems were part of the Advanced Unmanned Search System (AUSS) program that had its genesis in the early 1970s. This program, and the verity of these two vehicles showed that supervisory-controlled systems can be employed effectively. AUSS program evolutions encompassed a search database, computer modeling of search, subsystems evaluation, the test-bed prototype search system, and finally the improved delivery system. Throughout this program, from 1973 until 1993, engineers at Naval Oceans Systems Center continued the AUSS program, acquiring experience and applying their knowledge to improve both search technology and vehicle technology. System feasibility was fully demonstrated after the prototype was fielded, many lessons were learned, and the prototype experienced major evolutionary changes. The second system was a complete redesign, using state-of-the-art subsystems and technologies. The resulting product was capable and reliable, yet flexible, creating a plethora of system evolutionary possibilities. Sea tests, improved tactics, and systems engineering became synergistic and interactive. Increases in vehicle autonomy enhanced the human operator's capability to supervise by decreasing piloting and navigating burdens. The resulting system significantly exceeded expectations and was delivered to the fleet. The AUSS is shown in figure 9. Figure 9. AUSS AUSS involved pioneering research in underwater search and in UUV systems. Important knowledge was also gained in systems analysis, system engineering, and program evolution. Two systems have been built and fielded which in combination have experienced 114 untethered launches (and 114 successful recoveries) to depths between 2500 and 12,000 feet. AUSS proved it did not require a long, clumsy, and potentially dangerous leash. 28 Review of Autonomous Undersea Vehicle (AUV) Developments System tradeoff studies and analysis showed that an untethered search vehicle with supervisory control outperformed all other tethered, towed, and untethered options. Concurrently development of an underwater acoustic communications capability allowed supervised control without a tethered cable. Potential strengths of properly designed untethered systems are agility, stability, ability to hover in three dimensions, high forward speeds, rapid turns, combined with low risk of loss. Untethered systems, however, will not have enough self-intelligence in the foreseeable future to replace the human decision making capability afforded by vehicle/operator communications. The human operator, when allowed to supervise the operation of an untethered system, fills in where the untethered system is deficient: complex decision making. The human plans the mission and decides how to alter the mission based upon information obtained from both the support ship systems and the vehicle itself. The human analyzes vehicle sensor data and decides which anomalies in the data are of interest to the mission and therefore deserve further investigation, and which are not. The human operator can also alter the tactics pursued by the vehicle based upon environmental changes indicated in sensor data. Finally, the human operator is uniquely qualified to declare when the mission is completed. Autonomous systems can profit by the inclusion of a real-time (cable or fiber optic) or near-real- time (acoustic) communications capability during development testing. With this approach, the developers/operators have an opportunity to interact with the system and monitor system performance in real time while they work out system bugs. The evolution toward more autonomy with an untethered system can be carried to completion if the mission permits. Increases in AUSS vehicle autonomy have enhanced the human operator's capability to supervise by eliminating pilot and navigation burdens, and even allowed the matured AUSS vehicle to be used for certain complex, fully autonomous functions. These included performing sonar search patterns covering several square nautical miles and transiting long distances without operator commands being sent for hours. The prototype was a product more of evolution than of its original system engineering. Post- design breadboard-level implementations existed throughout, resulting in an unaccountable signal-to-noise ratio in the acoustic link system. Transmissions of high-quality images through the acoustic link required so much time that the rate at which the system could search was below optimal. The vehicle buoyancy system consisted of a pressure vessel providing less than adequate displacement supplemented by ad hoc, oddly shaped pieces of syntactic foam. The vehicle fiberglass fairings suffered from extensive modifications including holing, sawing, and gluing. The improved system’s ground-up design was based upon the prototype lessons. The electrical and acoustic signal-to-noise ratios were excellent. The vehicle computer systems were expanded and upgraded to the best available technology. Contractor-supplied surface console software was rewritten and ported to a network of off-the-shelf industrial computers. Original image compression algorithms were developed so the optical and sonar images were seen by 29 Review of Autonomous Undersea Vehicle (AUV) Developments the operator within seconds of acquisition, and the advance speed of the vehicle was optimized during sonar imaging for the travel time of the sonar pings. An important AUSS goal was to produce a small, lightweight system that could be transported easily and placed upon a large cross section of ships of opportunity. As with any overall vehicle system, the size of AUSS depends heavily upon the weight and size of the undersea vehicle. If the vehicle is allowed to increase in size, the launch and recovery gear, the handling gear, and the maintenance areas grow in kind. There is also a vicious cycle of growth associated within the self-powered vehicle design. A larger vehicle requires more propulsion power, requiring more energy for the same speed and endurance. More energy leads to more weight and volume in the energy source, which leads to a larger vehicle. Deep service syntactic foam is a much less efficient form of buoyancy than properly designed pressure vessels. Syntactic foam was used extensively on the AUSS prototype vehicle, as has been the case for many undersea vehicles. Thus a commitment was made to avoid its use on the improved vehicle. To meet this objective, several measures were taken. Extremely efficient graphite-pressure hull technology was developed with the prototype and applied to the improved system. A 30-inch-diameter graphite cylinder was manufactured to provide all of the buoyancy required for the improved vehicle. Other measures taken were the use of SpectraTM (which has a specific gravity very close to that of sea water) for the free- flooded fairings, magnesium for the chassis inside the vehicle, titanium for the wet connectors, and titanium and aluminum for redesigns of various sensor housings. The only syntactic foam in the system was the deployable nose float used for recovery. The time required for signals to travel between the surface and vehicle is dependent on speed of sound in water and the distance to the surface. Range of operation therefore affects the response time of the vehicle to supervisory commands, and it also affects the delay time taken for sensor information to reach the supervisor. These delays will increase with operational range, amounting to a round-trip delay of ten seconds or more at 20,000-foot depth with moderate standoff. The only way to prevent degradation of performance with range in an acoustically supervised system is to develop strategies that utilize vehicle autonomy. An example of more autonomy yielding better range independence is with an approach developed during the AUSS interactive sea test/development process for viewing objects on the bottom of the ocean. Neither the prototype nor the improved vehicles had side thrusters, and hovering over an object in a current proved impossible. With the prototype, pictures of the object were taken while the vehicle glided above the object at some forward velocity. The operator had to guess when to command the vehicle to take a picture. The combined acoustic link/supervisor reaction time increased with range to the vehicle. This process was marginally possible for ranges of 2500 feet, and would have been nearly impossible at the maximum range of 20,000 feet. During the improved vehicle evolution, an autonomous “hover at a radius" algorithm was implemented. This simple algorithm is analogous to a boat standing off from a buoy; the vehicle points at a position and maintains a given standoff from that position. The vehicle 30 Review of Autonomous Undersea Vehicle (AUV) Developments "weathervanes" into the current but remains aimed toward the target object. If the standoff distance is selected to be equal to the distance between the imaging camera (at the front of the vehicle) and the Doppler sonar (which is aft of the camera and is used to determine the position of the vehicle), the camera stays over the target. This is a completely autonomous routine that is range insensitive and requires only one supervisory command to send the vehicle to a target. As the AUSS system became operational and more dependable, a number of other innovative supervisory control system advances were invented to simplify the supervision of the undersea vehicle operations. Among these was target marking, wherein the location of a target object in the vehicle's onboard navigation coordinate system is automatically calculated when a cursor is placed over its image. Target marking was applied to Side Looking Sonar (SLS), Forward Looking Sonar (FLS), and Cooled Charged Coupled Device (CCCD) imaging portions of the AUSS mission. The synergy of hover at a radius and target marking made a significant contribution to the efficiency with which the system could view objects (targets) on the bottom. Each step in the target marking/hover at a radius sequence brings the AUSS closer to the objective target using successively shorter range, higher resolution sensing. An SLS target mark is used to determine a position for the vehicle to go to, hover at, and obtain an updated target mark with the FLS. FLS target mark is used to determine a position for the vehicle to go to, hover at, and obtain the first CCCD image. Finally, the cursor is moved about on the CCCD screen to mark positions for the vehicle to go to and obtain CD image coverage of the target area. Sixty-five hours of bottom time were logged during eight dives between 5 April and 24 June 1992. These eight dives produced some compelling results. During the showcase, SLS search rates were as high as 1.5 sq-nmi/hr. Contact evaluations (the process by which targets are found and imaged with CCD) typically took between 10 and 15 minutes. This process includes the time between the operator's identification of a potential target on SLS and the time when the vehicle was once again searching with SLS. The AUSS demonstrated fully operational dives between 2500 and 12,000 feet, depth-independent supervisory controlled search tactics, and excellent compression-enhanced acoustic link performance to 12,000 feet. During a single dive at 4000 feet, consistent SLS search was conducted at speeds between 4.5 and 5 knots with a swath of 2000 feet. The area searched during the dive was 7.5 sq-nmi, and the time to conduct SLS search and contact evaluations was 8.5 hours. This demonstrated an SLS search rate better than 1.5 sq-nmi/hr and an overall search rate (including contact evaluations) of 0.9 sq-nmi/hr. In another 4000-foot dive, over 2.5 sq-nmi were searched, including several lengthy contact evaluations and three photomosaics (series of overlapped CCD images taken while the vehicle performed a small search pattern over a target area). The contact evaluations included a 55- foot yacht and a Korean War vintage Skyraider night fighter aircraft that were both discovered and position pinpointed during the dive. An autonomous 5-nmi transit was also performed during the 14 hours the AUSS vehicle was submerged. 31 Review of Autonomous Undersea Vehicle (AUV) Developments During a 12,000-foot dive, the vehicle operated for 11 hours. The images were compressed and transmitted through the acoustic link at 2400 bps. Communications during the 12,000-foot dive were excellent, and search and contact evaluation tactics were proven to be depth insensitive. 32 Review of Autonomous Undersea Vehicle (AUV) Developments ROVER, AUTONOMOUS BOTTOM-TRANSECTING VEHICLE [15,16] The Scripps Institution of Oceanography (SIO) developed an autonomous underwater device available for performing long-term sequential measurements of benthic community activity. Sediment community oxygen consumption (SCOC) is one measurement of benthic community activity that has only been measured over short time periods of one month or less. SIO has developed and successfully collected data with a unique, autonomous, bottom-transecting vehicle (ROVER) that permits the first long-time-series measurements of SCOC (figure 10). This instrument was developed with the following capabilities: The instrument autonomously operates as a free vehicle on the sea floor to 6000-meter depth for periods up to six months. The instrument crawls across the sea floor, minimizing the impact that a long-term, free vehicle would have on measurement sites. SCOC is measured using two benthic chambers at up to 30 different sites over a single deployment. Sediment pore water oxygen concentration is measured using a microprofiler at up to 30 different sites over a single deployment period. e Incubation period is programmable for each SCOC measurement. e Operation of instruments and the surrounding area is monitored with time-lapse still and video cameras. e ROVER can be used as an autonomous programmable platform for a wide variety of benthic boundary layer measurements. e A water sample for oxygen or other analyses is collected at the end of deployment. ROVER Description The ROVER resembles a small forklift with a forward-mounted instrument rack, a savonious rotor and vane for measuring water currents, double-tread propulsion system, central battery packs and controller electronics, flotation, acoustic releases, and disposable ballast. The structural frame is constructed of titanium and fiberglass angle and tubing on which all the components are mounted. A polypropylene bumper extends ~30 cm beyond the vehicle frame to provide protection while handling the instrument during deployment and recovery. All materials and fabrication procedures used in the construction of each component of the ROVER were selected to minimize corrosion for long-term deployments to full-ocean depths (6000 meters). The overall dimensions of the Figure 10. ROVER ROVER are 2.74 meters long, 2.03 meters wide, and 2.19 meters high from the base of the propulsion treads to the top of the lifting bail. 33 Review of Autonomous Undersea Vehicle (AUV) Developments Instrument rack - The instrument rack consists of two cylindrical benthic chambers and an oxygen microprofiler mounted to a titanium vertically-moveable rack on the front of the ROVER frame. This assembly can be slowly lowered and raised with two titanium lead screws mounted vertically on both sides. Two acrylic transparent benthic chambers are mounted on either end of the instrument assembly. A bottom leading edge of thin, teflon-coated titanium reduces the force required to push the chambers into the sediment and eliminates adhesion of sediment to the chamber wall. A stirring bar, centrally mounted in each chamber, is driven by a pressure-compensated stepper motor via a magnetic coupling. This stirring assembly moves vertically on three titanium guide rods powered by a drive motor and a fine-scale lead screw. In the "up" position, the stirring assembly leaves a large hole in the chamber top, allowing the chamber to purge during insertion into the sediment. In the "down" position, the stirring assembly seals against an O-ring on the top plate of the benthic chamber. The oxygen-sensing system for each benthic chamber consists of a polarographic oxygen sensor and a flow cell. The oxygen sensor for each chamber on the ROVER is mounted in an external flow cell and is alternately exposed to chamber and ambient water using a pump and valve system. The ambient reference measurement is necessary to correct for long-term drift in the oxygen sensors and provides a direct comparison between chamber-water oxygen concentration during the incubation and stable oxygen concentration in the ambient bottom water. The flow-cell sample water is transferred by a DC motor-driven pump to the flow cell through plastic capillary tubing. A 3-position slider valve is used to switch the water supply to the flow cell from chamber to ambient, and this valve is under the control of the benthic chamber controller. A 1-liter Niskin bottle is mounted vertically on the instrument rack near one of the benthic chambers to take a water sample for dissolved oxygen analysis at the end of the last incubation. Closure of this bottle is triggered by a burn-wire release via the central controller. At each new measurement site, the instrument rack is lowered to place the oxygen microprofiler sensors just above the sediment and the benthic chambers ~6 cm into the sediment. The oxygen microprofiler is mounted on the instrument rack between the two benthic chambers. This microprofiler can accept up to 12 oxygen (or other) microsensors and four resistivity sensors that are arranged in a circular pattern on a plate that is mounted beneath the microprofiler-controller electronics cylinder. The titanium controller housing and electrodes are lowered stepwise toward the sediment surface by a fine-scale, DC-motor-driven lead screw (1 mm pitch). The resistivity sensors detect the sediment-water interface as a change in resistivity and allow the microprofiler controller to determine the sensor penetration depth into the sediment. Feedback from the resistivity sensors sets the system to profile an additional programmable distance into the sediment, and readings from each oxygen sensor are recorded at 0.5-mm increments. When the microprofiler completes the oxygen measurements to the programmed depth, the unit is retracted from the sediment. Oxygen sensor outputs from the benthic chambers and microprofiler are digitized and then transferred to the central controller for storage on a disk drive. 34 Review of Autonomous Undersea Vehicle (AUV) Developments Video and time-lapse still cameras - Two video cameras and flood lights are mounted on the ROVER frame to monitor the operation of the benthic chambers and microprofiler. The cameras and flood lights are operated by the central controller, and the cameras’ video output is recorded on two Sony camcorders housed in the central-controller pressure case. The recordings provide information on the penetration of the benthic , \qmmE™ > END @ chambers and microprofiler into the sediment and the eat Phy operation of the stir bars. The topography of the sediment surface and the activity of animals within the transparent chambers and around the microprofiler are also monitored by the video system. A time-lapse still camera mounted on the ROVER frame and a remote strobe light mounted on the instrument rack are used to photograph the area in front of the ROVER during transits between measurement , sites. Current rotor and vane - Near-bottom current speed and direction are monitored using a Savonius rotor. The turning speed of the rotor is detected by an optical sensor. Current direction is determined by a vane, magnetically coupled to a servo-potentiometer. Outputs from the current rotor and vane are recorded by the central controller Figure 11. ROVER-Current Monitors during the entire deployment. The current rotor and vane are mounted on a small arm, which is raised and lowered by a lead screw (figure 11). Propulsion system - The ROVER is propelled across the sea floor by two, flexible, fiber- reinforced PVC tractor treads (50 cm wide by 3.6 m long). Each tread is independently driven to allow directional movement, which is determined by the central controller. Treads have molded external cleats in order to ensure traction in soft sediment. Each tread is driven by a 1/8-HP DC motor and a reduction gear train, housed in oil-compensated PVC housings. A load-bearing, low-friction, polyethylene pressure plate supports each tread. Central controller with data storage and central battery - The propulsion system, instrument assembly, cameras, current rotor and vane are all controlled by a central controller which consists of a microcontroller, interface electronics, electronic compass, tilt sensor, and video camcorders. The microcontroller (Onset, Model 7) has a real-time clock, a 64-MB hard drive and a 12-bit A/D converter to digitize sensor outputs. It is located in a titanium pressure cylinder, mounted on the mainframe of the ROVER. The electronic compass (KVH Industries, Model C100) allows the ROVER to maintain course during transits and turns. A tilt sensor (Lucas, Model Accustar II) provides tilt information to the controller to determine if the Rover is approaching a mound or slope. The distance traveled by the ROVER over the bottom is estimated by a Hall-effect sensor that detects the revolution of magnets embedded in the forward drive roller. Power for the ROVER and its instrumentation is provided by two alkaline battery packs (180 D-cells each), located in independent titanium pressure housings mounted on the ROVER frame beneath the central controller. These batteries have a total capacity of 5000 watt-hours and are sufficient to power the ROVER in a typical deployment for up to 6 months. 35 Review of Autonomous Undersea Vehicle (AUV) Developments The operational status of the ROVER can be obtained by interrogating an acoustic transponder from a surface ship. The number of pings returned is increased as the ROVER progresses successfully through its program. Serious faults are indicated by a return to a single ping. Acoustic release and disposable ballast -Two acoustic releases in titanium pressure housings are mounted on the after end of the structural frame. Each release activates a remote burnwire trigger mechanism that can drop a disposable ballast rod of cold-rolled steel. With the release of either burnwire mechanism, the ballast falls between the treads, causing the instrument to become positively buoyant and rise off the sea floor. A submersible VHF _ transmitter, submersible flasher and flag mounted on the aft end of the ROVER and a second set on the mast assembly facilitate location by a ship in the vicinity. In the event of a premature release of the ballast there is also an ARGOS satellite transmitter mounted on the top of the ROVER for detection and tracking. Flotation — The ROVER’s flotation consists of 18 evacuated glass spheres (Benthos, 10 and 17 inch; Billings, 12 inch) mounted on the structural frame. The floats provide positive buoyancy of 385 kg, and an additional 41-kg buoyancy is provided by the floats on the recovery mast assembly. Syntactic foam was considered as flotation for the ROVER, but the added cost and air weight of foam proved excessive for the initial design. The spheres are inspected before each deployment for excessive spalling to reduce the chance of implosion. Weight and balance - In designing the ROVER it was critical that the instrument not sink too deeply into soft sediment, yet still be heavy enough to gain traction for maneuvering. The entire instrument weighs 40 kg on the sea floor, which permits optimum mobility with the double-track propulsion system. ROVER Operation The ROVER is deployed from a research ship using the ship's crane to lower the instrument into the water. (figure 12) A "quick-release" system is used to detach the ROVER from the crane’s hook. Once released, it takes about two hours for the ROVER to sink to the bottom in 4000 meters of water. After landing, the current rotor and vane-assembly are raised vertical by a lead screw in order to provide measurements of current speed and direction while the ROVER is on the sea floor. The central controller will monitor the current flow for a programmable period (about 24 hours) to determine predominant current flow direction. After the initial current monitoring period, the ROVER will wait for the right current flow conditions and then travel oe Benes ae upstream in the direction of predominant current flow. This way, any peace! hed instrument's tracks stir up will move downstream from the next measurement site. The ROVER will tvpically be programmed to move 5-10 meters from site Figure 12. ROVER — Ready to site. for Deployment 36 Review of Autonomous Undersea Vehicle (AUV) Developments At each measurement site, the instrument assembly with benthic chambers and oxygen microprofiler is slowly lowered into the sediment while being monitored by the two video cameras. Once implanted in the sediment, the central controller commands the benthic chamber controllers to begin their measurement cycles. The cycle begins by lowering the stir motor assemblies to seal the top of the chamber and starting the slow rotation (~9 rpm) of the stir bars. The oxygen level in the benthic chambers is measured for a period of 1-7 days, which is determined by the central controller. After the completion of an incubation period, the stir bars are stopped and retracted, and the instrument rack is raised above the surrounding bumper. After sequential sampling for periods up to six months (~30 sites), the instrument and current rotor and vane assemblies are retracted into their protected positions, and the ROVER is commanded to release its ballast and return to the surface. At the surface, the ROVER is located using the directional VHF transmitter and strobe. Four-Month Deployment The ROVER was deployed for a 4-month period beginning January 28, 1996 at Sta. M (34° 50'N, 123° 00' W; 4,100-m depth) 220 km west of the central California coast from the R/V Wecoma. The microprofiler was not used during this deployment, but SCOC was measured within the two benthic chambers. The ROVER was programmed to occupy 17 sites during the deployment with incubation periods of the benthic chambers at each site set for ~6 days. At the end of the 4-month deployment, the ROVER was recovered on June 1, 1997 using the R/V New Horizon. Analysis of the central controller data showed that the ROVER had completed its mission of crawling to the 17 measurement sites. Benthic chamber data and video recordings showed the chamber design largely performed its mission and useful data was recovered from most sites. The time-lapse camera operated correctly and returned many photos taken of the sea floor while traveling between measurement sites. This ROVER is particularly suitable in remote areas, such as polar regions or mid-basin portions of the Pacific and Indian Oceans that are difficult to occupy routinely due to logistical or weather constraints. It also can be operated at a fraction of the cost of using manned submersibles or tethered ROVs, especially in these remote or weather-limited areas. The ROVER can be used as a programmable platform from which to conduct a wide variety of research, including photographic transects, fine-scale bottom-water profiling for nutrients, fine- scale mapping of sea floor relief, and fine-scale mapping of sediment properties using sequential sediment cores and shear vanes. The increase in sampling resolution provided by the ROVER over conventional techniques should provide valuable insights into the dynamics of carbon cycling in the deep-sea benthic boundary layer. 37 Review of Autonomous Undersea Vehicle (AUV) Developments HUGIN 3000 [17,18,19,20,21] The HUGIN 3000 is the new and third generation of the HUGIN vehicles that were developed and operated in partnership with the Norwegian oil company, Statoil, the Norwegian Defense Research Establishment (FFI), and Norwegian Underwater Intervention (NUI). The HUGIN (figures 13, 14) project started in 1995, and the HUGIN vehicles have now performed more than 100 missions, including several commercial pipeline route surveys for Statoil in Norwegian waters. The HUGIN vehicles have so far proven very cost effective and will enhance quality of survey data compared to existing methods. The Hugin 3000, rated to 3000 meters, is 5 meters long and powered by a state-of-the-art aluminum oxygen fuel cell, providing a mission capacity of up to 48 hours before resurfacing. The AUV will carry a variety of sensors, including the EM 2000 multibeam echo sounder for bathymetry and imagery. Underwater positioning will be | performed using a HiPAP® Super Short Base Line (SSBL) system integrated with Doppler speed log, Inertial Navigation System, and for surface reference, Differential Global Positioning System eX Bsus (DGPS). Acoustic links for control of the AUV, reading of Figure 13. HUGIN 3000 Recovery sensor data, and emergency control are part of the delivery. C&C Technologies, an international hydrographic surveying company, has acquired and plans to use the HUGIN AUV as a deep-water survey tool for Minerals Management Service (MMS) Pipeline Hazard Surveys and Block Surveys. The HUGIN will provide the customer with engineering quality bathymetry data for the design of pipelines, pipeline risers, templates, and other sea floor equipment. Kongsberg Simrad's new deep-water dynamic Be==—= positioning (DP) and vessel-control functions and systems for the company's SDP/SVC/STC systems are designed to improve the safety and reliability of DP operations in deep water. These functions are enabling AUVs to be used for drilling, production, testing, and _ intervention operations that are traditionally accomplished with moored systems. [iipssssgaaeme ; - *s, Included in these systems is a riser management Figure 14. HUGIN 3000 in Operation system (RMS)--a result of cooperation with Seaflex and designed to improve drilling, workover, and completion of operations in deep water. These developments by Kongsberg Simrad are demonstrating that AUVs not only have significant cost advantages over current methods, but can also reliably undertake commercial survey work. Due to inherent low noise and high stability, HUGIN 3000-acquired survey data 38 Review of Autonomous Undersea Vehicle (AUV) Developments are typically of higher quality than data gathered with conventional techniques, such as surface tow and ROV-mount survey spreads. One major oil and gas company has already committed to C&C Technologies for HUGIN AUV survey work, and C&C is currently offering discounts for additional early commitments. 39 Review of Autonomous Undersea Vehicle (AUV) Developments ODYSSEY [1,22,23,24,25,26,27,28,29] During 1991 and 1992 a revolutionary new AUV was developed at the Massachusetts Institute of Technology (MIT) Sea Grant College Program AUV Laboratory. This vehicle, called Odyssey, was designed to provide marine scientists with economical access to the ocean. This first Odyssey AUV underwent field trials off New England in 1992 and was deployed from the National Science Foundation (NSF) icebreaker, the Nathaniel B. Palmer, off Antarctica in early 1993. Work on Odyssey was supported by the Sea Grant College Program, MIT, the National Science Foundation, and the National Underwater Research Program. The results of these deployments led to the creation of a second-generation vehicle, Odyssey Il, work that was supported by the ONR. In spring 1994, Odyssey II was deployed from an ice- camp in the Beaufort Sea in support of a program to understand Arctic sea-ice mechanics. All operations were carried out in a 15' x 15' tent, enclosing a hydrohole through five feet of ice. While at the ice camp, Odyssey II performed a series of "out-and-back" missions, demonstrating its ability to home into the recovery net. These tests set the groundwork for providing a unique capability for responding to transient events in the ice. Odyssey is propelled by a motor running on batteries that can last six hours on a typical mission. Mounted in its nose for this pilot experiment is Crittercam, a computer-controlled video camera. Odyssey’s antenna communicates with a radio beacon for locating the robot sub; the strobe has the same function. The acoustic transponder enables operators on Tanekaha to track Odyssey (figures 15 and 16). See table 7 for specifications. ” A Nee ee os RADIO FREGUENCY BEACON LIFT ACOUSTIC RUDDER POINT TRANSPONDER LOCATING STROBE | PROPELLER CRITTERCAM Di will RUDDER DBSTACLE AVOIDSNCE SONAR Figure 15. Odyssey Under Sea Grant support, Odyssey II was operated from the National Oceanic and Atmospheric Administration (NOAA) ship Discoverer as part of the 1994 and 1995 VENTS programs (in a collaboration with the NOAA Pacific Marine Environmental Laboratory). A combination of 40 Review of Autonomous Undersea Vehicle (AUV) Developments tethered and free-swimming dives demonstrated navigation and tracking of the AUV over the Juan de Fuca Ridge, and fully-autonomous, untethered operation, as deep as 1400 meters. In 1995, four new vehicles were built under ONR sponsorship. As some elements of the design were improved, these vehicles are denoted Odyssey IIb. The original Odyssey I] was upgraded to be the same as the Odyssey Ilb vehicles. Some of the vehicles have been loaned to collaborators at Woods Hole, the Navy NRaD center in San Diego, and to industry (Electronic Design Consultants in Chapel Hill, North Carolina). These vehicles have proved to be relatively simple to use and robust when operated by non-MIT personnel. For example, in June 1996 two of the Odyssey IIb AUVs were used in a month-long experiment that studied the dynamics of frontal mixing in the Haro Strait, off Vancouver Island. The vehicles carried water quality sensors, a side-scan sonar, and a water-current profiler. Over a 21-day period, the two vehicles performed 67 dives with no failures of the base vehicles and only one day lost to weather. The 430-pound (195-kilogram) robot sub is hoisted in and out of water via its lift point. Figure 16. Odyssey Launch/Recovery Table 7. Odyssey Specifications Displacement 165 kg Thruster 1 electric (brushless), 20 lbs max. thrust Depth rating 6000 m Power Silver-Zinc Cells, 3.2 kW-hr Endurance/Range 12 hours @ 5 km/hr Onboard Computer 68040 based Statu 5 Operational AUVs Reliability Over 400 dives with no vehicle losses Payloads CTD, ADCP, Camera, Side-scan Sonar 41 Review of Autonomous Undersea Vehicle (AUV) Developments LITTORAL OCEAN OBSERVING AND PREDICTIVE SYSTEM (LOOPS) [30] This project includes twelve partners from academia, government laboratories, and industry for the development of the scientific and technical conceptual basis of a generally applicable interdisciplinary littoral ocean and observing system, the Littoral Ocean Observing and Predictive System (LOOPS). A modular structural concept for linking, with feedbacks, dynamical models, and measurements via data assimilation will be developed, with an emphasis upon adaptive sampling, flexibility, and portability. The integrated system software architecture and infrastructure will stress versatility and efficiency via central databases for the measured ocean and the estimated ocean. Research to be carried out includes Observational System Simulation Experiments (OSSEs) for generic coastal processes and a range of civilian and naval application areas and sea trials to explore issues in the real-time implementation of LOOPS. The partners bring to the program diverse and relevant expertise and experience in interdisciplinary ocean science; systems and ocean engineering; data assimilation and ocean prediction methodologies; and synthesis and collaboration, as well as a suite of existing robust and tested measurement and model components for integration into the overall system. ATLANTIC LAYER TRACKING EXPERIMENT (ALTEX) [31,32] The project goal is to develop AUVs capable of observing basin-scale evolution in the Arctic (figures 17, 18). This requires the development of energy, navigation, and communication systems specifically tailored for extended autonomous operations under ice. One program objective is to provide a means of monitoring changes taking place in the Arctic Ocean and investigate its impact on global warming. Such a capability is of national and global interest and \ Trackpoint \ transponder ULS Pressure = One-piece LJ sana LB | pees ore modem control surlaces transducer | seth transponder individually iy | addressable FAU connector, but | Hull is gel-coated kevlar FAU “Podule* with Ti instead of Al | Shape: Series 58, 4154E Stainless steal, | with a oylindriolal midsection not PVC, housing Fuel cell will have enough tloation to be neutrally buoyant 17° Benthos sphere with Main Vehicle Computer Attitude Heading Reference Sonar ronios acoustic modem electrorics CT electroics Figure 17. ALTEX-Reference Vehicle Mechanical Layout 42 Review of Autonomous Undersea Vehicle (AUV) Developments importance. A modular AUV with parallel mid-body sections is being developed. The general AUV design called the Atlantic Layer Tracking Experiment (ALTEX) minimizes the use of pressure housings, putting as many systems as possible in smaller, lighter oil-filled (pressure- compensated) enclosures resulting in a small, deep-rated system. To achieve the desired range capability, the ALTEX program will employ a fuel cell energy system constructed by a team composed of Yardney Technical Products and Fuel Cell Technologies (FCT), Ltd. The system being developed is unique in that it will be pressure compensated and therefore deep- ocean rated. Communication will be provided by buoys designed to melt through the ice and telemeter mission data via Argos. The buoys will also be equipped with GPS, so that a position fix can be obtained. Other components of the vehicle will be a mix of systems developed for earlier generations of AUVs by the partner organizations. While some new systems are being developed, the objective is to leverage existing technology to the highest degree possible. The AUV capability goals are to deliver a suite of oceanographic and mapping sensors up to 1000 kilometers and down to least 1500 meters. Research will also be directed toward the development of communication systems using self-locating transponders that are remotely installed in the ice. Buoy launcher —_ & ae 7 ‘¥ Contral sphere P Thruster s Internal Structure Fairing panels Figure 18. ALTEX — Exploded View 43 Review of Autonomous Undersea Vehicle (AUV) Developments AUTONOMOUS OCEAN SAMPLING NETWORK (AOSN) [32,33,34,35] The long-term goals of this project are to create and demonstrate a reactive ocean survey system, capable of long-term unattended deployments in remote environments. Such a system is referred to as an Autonomous Ocean Sampling Network (AOSN). The work described Institute of below is the product of a collaboration of research groups at MIT, Woods Hole Oceanographic Institution, SIO, University of Washington, and Northeastern University. The objective of this project is to create and demonstrate the next-generation robotic oceanographic survey system. This is being accomplished by: 1) Creating small, high-performance mobile platforms capable of several month deployments. Both propeller-driven, fast survey vehicles and buoyancy-driven glider vehicles have been developed. 2) Creating an infrastructure that supports controlling, recovering data from, and managing the energy of, remotely deployed mobile platforms. Elements include moorings, docking stations, acoustic communications, two-way satellite communications, and the Internet. 3) Demonstrating these capabilities in science-driven field experiments. 4) Developing operational techniques that make most effective use of these new assets, including adaptive sampling strategies. 44 Review of Autonomous Undersea Vehicle (AUV) Developments CETUS [36] In response to a request by Lockheed Corporation for the development of a flatfish-type AUV for mine countermeasures, the CETUS vehicle (figure 19) was designed and built at MIT Sea Grant's AUV Lab. The vehicle is designed to be passively stable, easily controlled, and capable of hovering. The project objective was to produce a vehicle that was not only inexpensive to manufacture but also durable and easy to service. The final design has a single-piece High-Density Polyethylene (HDPE) hull, formed using a rotational molding process. It employs two propulsive thrusters and three hovering thrusters, with no active control surfaces. The fabrication, from concept to delivery, was achieved in nine months. Specifications are listed in table 8. Figure 19. CETUS Table 8. CETUS Specifications Hull Size Length 1.8m, Width .8m, Height .5m Hull Composition Rotary-Molded High-Impact Plastic Weight 100 kg stand-alone, 150 kg with ALS and additional sensors Depth Rating Al Pressure Vessels 200m, Titanium PV >4000m Control Differential Thrust Propulsion Brushless DC Thrusters Power Battery (lead acid) Speed Cruising 1.5 - 2.5 knots, Maximum 5 knots Range 20-40km (speed/sensor dependent) 45 Review of Autonomous Undersea Vehicle (AUV) Developments COMMANDER, NAVAL METEOROLOGY AND OCEANOGRAPHY COMMAND Requirements for oceanographic environmental support are identical to optimizing effectiveness of Navy high-technology warfare systems. With the Navy's shift to littoral operations, these requirements have increased significantly. Commander, Naval Meteorology and Oceanography Command (COMNAVMETOCCOM) is emphasizing integration of UUVs into the survey fleet as force multipliers to meet this increased demand for environmental support of several Integrated Warfare Architecture (IWAR) sub-domains. Naval Research Laboratory, South (NRLS) worked with an ISE developed "Dolphin" UUV, changed its name to "ORCA," and developed it as a force multiplier for survey work. This air-breathing internal-combustion engine-powered UUV was the prototype for the Remote Mine-hunting System (RMS) currently being developed. SEAHORSE COMNAVMETOCCOM's entry into the large UUV realm was initiated with the transfer of vehicles (1997/98) developed and tested at Draper Labs under the Defense Advanced Research Projects Agency (DARPA) project. The Naval Oceanographic Office (NAVOCEANO) teamed with Penn State University Applied Research Laboratory (ARL) to integrate commercial off-the-shelf (COTS) systems to build the SEAHORSE-class UUV, a low-cost, long-mission- endurance vehicle for standard shipboard deployment (figure 20). The design emphasizes: e Modularity for quick turnaround shipboard maintainability in forward-deployed modes--rapid energy refurbishment and sensor payload change out e Use of commercial oceanographic sensors that have been integrated and proven in the small UUV realm, and low-cost D-cell power pack technology e Propulsor and autonomous control designed for shallow-water, energetic environments The benefits to oceanographic surveys to be realized with SEAHORSE include: e Force multiplier for T-AGS 60 oceanographic survey vessels e Progress on UUV Priority III to provide large-area oceanography and tactical oceanography support e Compatibility with standard NAVOCEANO oceanographic sensors e Autonomous operating range of 300 nmi or 72 hours with existing battery system e Deploy and leave ability increases survey effectiveness by allowing T-AGS 60 to depart SEAHORSE survey area and conduct surveys in other ocean areas e Autonomous operating range of 1000 nmi, or more than one-week deployment time with future battery system 46 Review of Autonomous Undersea Vehicle (AUV) Developments Figure 20. SEAHORSE Launch SEMI-AUTONOMOUS MAPPING SYSTEM (SAMS) NAVOCEANO is also pursuing small UUV technologies in the form of a modified Woods Hole Oceanographic Institution REMUS vehicle, identified as Semi-Autonomous Mapping System SAMS leverages existing Towed Oceanographic Survey System (TOSS) Relative Acoustic Tracking System (RATS) to achieve precise acoustic positioning. installation of upgrades, SAMS design focuses heavily on the application of COTS sensors. Drop weights are utilized to reduce time and energy consumption during pre-mission descent Power is provided via commercially available lithium-ion batteries. (SAMS). and post-mission ascent. The capability improvements and benefits to be realized with SAMS include: Extended capability of existing TOSS full-ocean depth camera and side-scan sled Increased rate of survey coverage, reduced ship time, and/or significantly increased survey coverage and data collection Progress on UUV Priority Ill to provide large-area oceanography and tactical oceanography support Greater positioning accuracy via internal navigation system Compatibility with existing ship stowage, deployment, and retrieval systems 14-hour autonomous survey time Uninterrupted survey with continuous two AUV rotation operational plan 47 To simplify Review of Autonomous Undersea Vehicle (AUV) Developments WOODS HOLE OCEANOGRAPHIC INSTITUTION Woods Hole Oceanographic Institution is dedicated to research and higher education at the frontiers of ocean science. Its primary mission is to develop and effectively communicate a fundamental understanding of the processes and characteristics governing how the oceans function and how they interact with Earth as a whole. Two key AUV developments at Woods Hole Oceanographic Institution are the Remote Environmental Monitoring Units (REMUS) and the Autonomous Benthic Explorer (ABE). REMOTE ENVIRONMENTAL MONITORING UNITS (REMUS) [37] REMUS, or Remote Environmental Monitoring Units, is a low-cost AUV developed by the Oceanographic Systems Laboratory for coastal monitoring and multiple vehicle survey operations. As described in table 9, the current vehicle is 53 inches long with a body diameter of 7.5 inches, although the length may be increased to support any reasonable payload. Weighing only 68 pounds in air, REMUS (figure 21) is neutrally buoyant in water and is powered by sealed lead acid batteries. The vehicle can be operated in fresh or salt water. Because REMUS is so small, it can be easily transported by compact car, is air shippable as baggage, and may be launched and recovered from a small vessel; special handling equipment is not required. Figure 21. REMUS 48 Review of Autonomous Undersea Vehicle (AUV) Developments Although small in size, the REMUS vehicle is configured to support a variety of sensor packages. The vehicle has a CTD (conductivity/temperature/depth) sensor and an optical backscatter sensor on board. Telemetry data provides time of day, depth, heading, and a geographic fix for the data. A longer version of REMUS with an acoustic doppler current profiler and GPS system is undergoing tests. Additional PC-104 slots and RS-232 ports are available for user-designed payloads. REMUS has three motors forward of the propeller. The REMUS propulsion assembly is optimized to provide 1.5 pounds of thrust at a forward speed of 4 knots. At this speed a 40- nautical-mile track can be completed in 10 hours. REMUS runs from a 24-volt power supply and draws approximately 32 watts while maneuvering through the ocean, enabling the vehicle to operate at 4 knots for 14 hours. The REMUS control computer is based on PC-104 technology, a small-scale computerized version of the common IBM-PC hardware. The CPU sits in a custom motherboard, on which are eight 12-bit analog to digital channels, input/output ports, power supplies, and other interface circuitry. Internally, REMUS runs a DOS program written in C++ that executes out of an autoexec.bat file. The vehicle user interface is designed to run on a laptop computer. REMUS possesses a sophisticated acoustical system with a digital signal processor. A receiving array of four hydrophones is located in the nose, and on the bottom is a hydrophone that can both transmit and receive. To determine its position, REMUS transmits a coded ping to a transponder and listens for a reply. The range and bearing of the reply allows REMUS to determine its location. REMUS can be programmed to interrogate a trail of transponders, approaching each transponder by minimizing range. When the range to a transponder is below a predetermined threshold, the vehicle then listens on a different channel for the next transponder and approaches it using the same technique. By setting the transponders once using GPS, a known trackline may be followed on mission after mission. This system has been used to autonomously dock the vehicle. Table 9. REMUS Specifications Length: 53 inches (1.3 meters) Beam: Approx. 5.5 feet Diameter: 7.5 inches (19.1 cm) Maximum Operating Depth: 492 feet (150 meters) Gross Weight: 68 Ibs. in the air, neutrally buoyant in water Dive Duration: 14 hours at 4 knots Propulsion: Three motors; one direct drive thruster and sprocket-driven rudder, two pitch motors, and one stem propeller Power requirements: 24-volt supply, 32 watts while maneuvering at 4 knots Power Source: Rechargeable lead acid batteries 49 Review of Autonomous Undersea Vehicle (AUV) Developments AUTONOMOUS BENTHIC EXPLORER (ABE) [1,38] The Autonomous Benthic Explorer (ABE) (figures 22 and 23) was designed to address the need for long-term monitoring of the sea floor which is very expensive using a surface ship for repeated visits with ALVIN or Jason. While manned submersibles and ROVs allow intensive study of an area, they can remain on station for only hours, days, or weeks. Consequently, a system that can remain in an area gathering data to fill the time voids between submersible and ROV visits would provide another level of more detailed information on temporal variations. Cameras and other fixed instruments may not always be the best solution to this problem because they have limited spatial coverage and are vulnerable to fouling from bacterial growth or mineral deposits. After discussions with many scientists studying hydrothermal systems, the concept of a roving robot that could remain working on station for up to a year was developed. The robot would spend most of its time "sleeping" in a safe location, then, at pre-programmed intervals, undock, perform a survey with video cameras and other sensors, then redock and go back to "sleep." From these ideas, the ABE was created and built at Woods Hole. ABE is a true robot, able to move on its own with no pilot or tether to a ship, and designed to perform a predetermined set of maneuvers to take photographs and collect data and samples within an area about the size of a city block. During long deployments, ABE will “sleep” at a docking station between data excursions, conserving power for months of extended operation. ABE was developed by a team of engineers, who assembled what might be called the robot's body, muscles (thrusters), nerves (cabling and power to operate the motors, cameras, and sensors), and brain (computer systems for powering up and down and for determining where to go and when to make measurements). Each of these components presented a complex design challenge. Currently, ABE follows a set of instructions placed in its memory before deployment and is recovered for data download following an excursion. However, its developers envision the not- too-distant day when underwater acoustic transmission systems now being developed will allow scientists anywhere in the world to receive video and data from ABE and to control its movement and measurements from their home laboratories. To minimize cost, ABE is a three-body, open-frame vehicle. This allows glass balls to be used for flotation (there are three in each of the two free-flooded, upper pods), and all the batteries and electronics to be placed in a single, lower housing. This separation of buoyancy and payload gives a large righting moment that simplifies control and allows the propellers to be located inside the protected space between the three faired bodies. ABE has seven thrusters and can move in any direction. It can travel forward at 1m/sec on about 50 watts to its motors. Navigation and control take only about 12 additional watts. 50 Review of Autonomous Undersea Vehicle (AUV) Developments Figure 22. ABE As presently configured, ABE's principal data are CTD, magnetometer, bathymetry, and monochrome stereo image pairs of the bottom at selected locations. The image recording system has been designed and built in collaboration with Electronic Imaging Systems, Ltd. of Oxford, England. The imaging system is capable of supporting as many CCD cameras as desired with resolutions up to 1Kx1K. Cameras may be of different types and resolutions. They may be in separate housings and may be aimed in different directions for different missions. The system captures all images simultaneously from a single photoflash. Currently, two downward-pointing monochrome cameras are installed for stereo imaging. Each provides an image resolution of 576x768 pixels with a dynamic range of 8 bits. The images are stored digitally on two hard disks. The current disks can store approximately 4500 image planes (one color image has three planes while each monochrome has only one). They can be upgraded to provide more images than any researcher would want, limited mainly by system power consumption from the vehicle's batteries. ABE is powered by rechargeable, gelled lead-acid batteries to facilitate testing and reduce cost. Even with these batteries, ABE could travel over 50 kilometers in a straight line. In any real mission, however, the energy required to maneuver, operate sensors, and power the flash will limit the range to a fraction of this value. For a long mission, alkaline batteries could be used for 51 Review of Autonomous Undersea Vehicle (AUV) Developments a four-fold improvement in energy available. Ultimately, lithium batteries will be installed for an improvement of more than twelve-fold in energy, compared to the present lead-acid cells. In order to accomplish its scientific objectives and ensure vehicle safety, ABE must have reliable and precise navigation and control. Two complementary navigation systems that are already proven in previous deep-ocean operations have been selected. Medium-frequency (10- to 14- kHz) transponders, identical to those used for ALVIN, guide ABE during descent to its worksite and are used to navigate for surveys over long distances. With this navigation system, ABE has the ability to follow tracklines with repeatability of several meters. At the worksite, ABE switches to broadband 300-kHz transponders to navigate precisely over ranges of about 100 meters with a repeatability of several centimeters. This system (EXACT) has been demonstrated on the ROV Jason at Endeavour and Guaymas Basin vent sites. With two navigation hosts on the vehicle and two transponders, ABE can obtain a range and bearing from either transponder, or it can obtain a long baseline fix when ranges to both transponders are available. In on-going dockside tests, ABE demonstrated the capability to hover and follow tracklines within several tens of centimeters, and most importantly, to return to its docking mooring. In addition, ABE's power consumption during closed-loop maneuvers falls well within previous estimates. In spring 1993, as soon as it was mechanically complete but before the navigation system was installed, ABE was taken out on the ATLANTIS II during a series of ALVIN engineering dives. An anchor was rigged on 60 meters of line below ABE, and the combination was allowed to free-fall to the seafloor at a depth of 1600 meters. After reaching the bottom, ABE exercised its seven thrusters one at a time, recording the rpm resulting from the varying torque commands. This tested the control system, internal communication bus, power system, and all the thrusters. At the end of the test, ABE released its anchor and freely ascended to the surface. ABE's progress was monitored by measuring the range to one of its two built-in transponders. It was quickly located on the surface. Since then, ABE's capabilities have grown and it was taught to perform increasingly involved tasks. In summer 1993 it performed brief autonomous missions using dead-reckoning navigation. The video system and the EXACT navigation system were added in fall 1993. The navigation system is currently performing well and allows ABE to hover (holding x,y,z and heading) in strong tidal currents with only a few centimeters of wander. Forward or sideways movements can be commanded, and ABE executes them smoothly. In addition, ABE can find the beacon that marks its docking mooring, turn toward it, and dock. In June 1994, ABE was shipped to join the ATLANTIS II in San Diego, again in conjunction with a series of ALVIN engineering dives. ABE's capabilities to conduct repeated dockings, follow tracklines within the ALVIN transponder net, and capture images at specified locations were demonstrated. The first real science mission occurred in mid-1995, when ABE was used to conduct a complete magnetometer survey over a lava flow, known to have erupted in July 1993 along the Coaxial Segment of the Juan de Fuca Ridge. A previous survey conducted from ALVIN indicated the 52 Review of Autonomous Undersea Vehicle (AUV) Developments presence of a notchlike magnetic low at the center of the new flow, which has been interpreted to be related to the thermal demagnetization of the underlying feeder dike. Figure 23. ABE Launch The survey with ABE flew at an altitude of 20 meters above the bottom and covered an area of 1 kilometer by 300 meters with about 20-meter spacing between tracklines. ABE was designed to investigate how this anomaly changes with time, thereby providing constraints on the cooling and structure of the lava flow. In 1996 ABE was back on the Juan de Fuca Ridge, this time in conjunction with the ROV Jason. ABE mapped the magnetic field above a feature called New Flow, flew over Cage Seamount, and explored the Gorda New Eruption site. Long-baseline navigation significantly improved, and ABE flew closed-loop tracklines using its in-hull navigation in real time. This made the surveys much more efficient and gave more direct control to the science party. ABE's standard data products include the following items: e Vehicle position determined at the long-baseline (LBL) transponder cycle interval, typically every 10 seconds (water depth dependent). These data are obtained by ABE directly, so errors caused by uncertainties in the sound velocity profile of the water column are minimal. 53 Review of Autonomous Undersea Vehicle (AUV) Developments Vehicle science sensors, sampled at the LBL interval. These include three axis magnetometer (Develco 9200C-01), Seabird conductivity and temperature sensors, and an optical backscatter sensor (Seapoint Turbidity Meter). Vehicle attitude (pitch, roll, heading), depth, and altitude at the LBL cycle interval or at higher rates up to two samples/second. Pitch and roll are measured with inclinometers; heading is a composite estimate obtained from a flux gate compass and a rate gyro. Depth is measured with a Paroscientific pressure sensor. Altitude is obtained from the acoustic altimeter, which points forward 30 degrees and has a beamwidth of approximately 15 degrees. Video snapshots: ABE can take simultaneous monochrome stereo pairs at intervals of 10 seconds (currently this rate is limited by strobe recharge time). Each camera provides an image resolution of 576 x 768 pixels with a dynamic range of 8 bits. ABE can provide about 2500 image pairs on a single dive. These cameras can be oriented to optimize stereo or panoramic imaging. The images can be viewed and processed with a variety of commercial imaging software packages (i.e., PhotoShop or PhotoPaint) for PCs, Macintosh and Sun computers. Engineering data from the vehicle are also available if desired. These data include commanded thrust levels, measured propeller speeds, battery voltage and power consumption. Imagenix 675-kHz scanning sonar for cross-track bathymetry out to ranges of approximately 40 meters. Sensors in development include: Doppler navigation and current profiling: A 1.2-MHz RD Instruments doppler was ordered to operate both as a bottom lock navigator and to determine the 3-D current profile beneath or above the vehicle. Improved strobe: This will provide an option for image rates of 5 seconds and improved beam pattern. Higher image capacity: The hard drives for the image data could be swapped out for higher capacity if needed. New cameras: ABE's video system can be configured for a variety of commercially available cameras, both monochrome and color. ABE specifications are detailed in table 10. 54 Review of Autonomous Undersea Vehicle (AUV) Developments Table 10. ABE Specifications Length: 10.5 feet (3 m) Beam: Approx. 5.5 feet Height: 5 feet Gross Weight: 1,500 Ibs. Maximum Operating Depth: 20,000 feet (6,000 meters) Dive Duration: 6 hours to 1 year, 4-100 active hours Propulsion: 7 thrusters Navigation: Medium frequency (7-14 kHz) transponders guide ABE during descent to the worksite and are used to navigate for surveys. Power requirements: Sleep: 50 milliwatts Maximum Propulsion Power: 200 watts Science Power: 10-100 watts Vehicle Navigation and Control Power: 17 watts Power source: Option 1: Lead acid rechargeable cells - 1 kWh usable Option 2: 2-5 kWh usable (rate dependent) Option 3: Lithium primary cells - 17 kWh usable (expensive) 55 Review of Autonomous Undersea Vehicle (AUV) Developments OCEAN VOYAGER II AND OCEAN EXPLORER [39] The AUV program is an ever-expanding field of study in the Ocean Engineering Department of Florida Atlantic University (FAU). Small, low-cost, long- range vehicles have been developed as sensor platforms for educational, scientific, and military applications. Currently, two separate vehicles are under construction, development, and refinement: the Ocean Voyager II (OVII) and the Ocean Explorer series. Several projects directly related to the vehicles themselves are underway at the FAU Ocean Engineering Department and at the University of South Florida Marine Science Department. Some of these include CHIRP side-scan and sub-bottom sonar, passive imaging sonar, long baseline sonar, acoustic modems, exotic batteries, ocean small-scale turbulence sensors, and various suites of water quality packages. ies h Figure 24. Ocean Voyager Il The OVII (figures 24 and 25), was initiated as the child of 23 seniors of the Ocean Engineering Department in fall 1992. It was the senior design project of this class to design a practical AUV to carry a sensor package designed by the University of South Florida (USF) to measure the shallow-water coastal environment. These data are then used to ground truth data from satellites currently in orbit. OVII has been operational since January 1994 and is continually upgraded and modified by the staff and students here as tasks dictate. This vehicle has also been used to test CHIRP sidescan and sub-bottom sonars being developed here, as well as LBL navigation techniques. Following operations in the Dry Tortugas off the Florida Keys in August, the vehicle is slated to be turned over to USF for continued operations with their instrument packages. The instruments aboard the OVII are the Bottom Classification Albedance Package (BCAP), an _ integrated suite which includes a Xybion multispectral downward-looking camera, upwelling and downwelling radiometers, fluorometer, transmissometer, and pencil lasers for sizing. The Bottom Classification and Albedo Package (BCAP) is an ensemble of optical sensors used to calibrate algorithms and validate satellite ocean color data in the coastal oceans. BCAP was prototyped aboard an ROV and has, since June 1995, been routinely deployed aboard OVII. Figure 25. OVII Cut-Away 56 Review of Autonomous Undersea Vehicle (AUV) Developments The Ocean Explorer is not just a single AUV but rather the name for the next generation of several vehicles currently being built. This is a new family of AUVs of modular construction, with hull, sensors, and software easily convertible for different payloads. The one pictured in figure 26 has been named COOK. It uses an extensive intelligent distributed control system called Figure 26. COOK LonWorks (Neuron) for communications between numerous sensors and actuators. It is presently undergoing tests in the local waters around FAU. The docking system allows an Ocean Explorer AUV to rendezvous and dock with its base station using fuzzy logic control. Note: The 3-foot parallel midbody version, containing approximately 7.5 cubic feet of payload volume. This version is about 10 1/2 feet long. The base vehicle is about 7 1/2 feet in length. Payload interfacing specifications are depicted in table 11. 57 Review of Autonomous Undersea Vehicle (AUV) Developments Table 11. Ocean Explorer Payload Interface Specifications = Available Power: 48 Volts (42-56V) 5A max. current Cables/Connectors: Power/LonTalk Network SeaCon FAWM Series Pin 1 BATTERY GND Pin 2 BATTERY +48V Pin 3 BATTERY GND Pin 4 BATTERY +48V Pin 5 BATTERY GND Pin 6 BATTERY +48V Pin 7 LonTalk Data A Pin 8 LonTalk Data B Note: LonTalk Data Lines A&B must be a twisted pair. Ethernet/Serial SeaCon FAWM Series Pin 1 TD+ 10Base-T Ethernet Pin 2 TD- 10Base-T Ethernet Pin 3 RD+ 10Base-T Ethernet Pin 4 RD- 10Base-T Ethernet Pin 5 EIA-232 Common Pin 6 ElA-232 TX Pin 7 EIA-232 Common Pin 8 EIA-232 RX Note: 10Base-T TD+/- and RD+/- are twisted pair. Power The Power/LonTalk network cable supplies 48-volt power. The maximum allowable current for a payload is 5A. The Ocean Explorer AUV total battery storage capacity is 40 Ampere-hours at a nominal voltage of 52V. This capacity is divided into eight 5-Ampere-hour battery packs. If the total capacity is insufficient, additional battery modules can be added to the payload compartment. BATTERY GND (pins 1, 3, and 5) should not be connected to the pressure vessel (i.e., seawater) which houses the payload electronics. If the payload circuit ground must be connected to seawater, then an isolated power supply should be used. Communications The preferred method of communication between the AUV and payload is through the LonTalk network (connections in the Power/LonTalk cable). The Lon/Talk network is used to communicate directly with any of the sensors or actuators that comprise the AUV's distributed control network. Typically a serial gateway module is provided to the payload manufacturer for incorporation into the payload. The serial gateway module provides a bridge between EIA-232 communications and the LonTalk network. Custom software for the serial gateway module must be written to implement the desired functionality. The Ethernet/Serial cable contains a 3-wire ElA-232 serial communication channel that connects to a serial gateway module in the main pressure vessel. This module provides an EIA-232 to LonTalk network interface. Custom software for the serial gateway module must be written to implement the desired functionality. This connection would normally be used when installation of a serial gateway module in the payload is impractical. The Ethernet/Serial cable also contains a 4-wire (two twisted pair) 10Base-T Ethernet channel. This is connected to a 10Base-T hub in the main pressure vessel. Either a cable or wireless Ethernet links the AUV to a surface vessel. 58 Review of Autonomous Undersea Vehicle (AUV) Developments AUTONOMOUS UNDERSEA SYSTEMS INSTITUTE (AUSI) [40,41 ,42,43] The Marine Systems Engineering Lab (MSEL) began at the University of New Hampshire (UNH) in 1976. MSEL personnel and facilities moved to the Marine Science Center of Northeastern University located in Nahant, Massachusetts in July 1993. In January 1996, the laboratory moved back to New Hampshire to continue its research activities as part of the Autonomous Undersea Systems Institute (AUSI). AUSI has been funded mainly through grants from the ONR and the NSF. AUSI also provides its facilities and expertise to support research programs at other institutions. AUSI continues to organize and conduct International Symposia on Unmanned Untethered Submersible Technology. AUSI, along with the Institute for Marine Technology Problems | (IMTP) in Vladivostok, Russia, are investigating the characteristics and limitations of using solar energy as an energy source for a long- endurance AUV (figure 27). The prototype testbed is being used to evaluate the results of a number of analyses related to the solar- powered AUV. The ultimate objective is to develop a solar-powered | AUV system for the marine community with endurance in excess of | one year. Cooperative Distributed Problem Solving for Controlling Semi- fas = Autonomous and Autonomous Oceanographic Sampling Networks Figure 27. Recovery of (AOSNs). Successful deployment of AOSN systems will rely on Solar Powered AUV coordinated, flexible, and adaptive behavior among the system's various participants. The Cooperative Behaviors project investigates such coordinated behavior. This project's goal is the development of protocols and mechanisms for intelligently planning and controlling AOSNs. Cooperative Autonomous Underwater Vehicle Development Concept (CADCON). The AOSN concept is broad and far reaching. AOSN developers must deal with a huge list of intertwining issues. The technical problems associated with the design and development of such a complex system are many and varied; as a result, AUSI developed ideas relative to the sort of development environment that would better enable AOSN work. These ideas were formalized as the Cooperative AUV Development Concept (CADCON). Development of Basic Autonomous Vehicle Behaviors. AUSI is developing and testing a prototypical set of behaviors which will provide a functionally robust mobile underwater vehicle. Initial research findings show that complex and robust behavior can arise from fairly simple heterogeneous neural networks. In short, this body of researchers has engendered a new branch in artificial intelligence/robotics that focuses on a bottom-up approach to the issue of autonomous agent behavior. 59 Review of Autonomous Undersea Vehicle (AUV) Developments THE COMMISSION FOR GEOSCIENCES, ENVIRONMENT AND RESOURCES (CGER) [44] The Commission for Geosciences, Environment, and Resources (CGER) oversees and coordinates the activities of the National Research Council in the broad areas of atmospheric sciences and climate, oceanography, solid-earth sciences, radioactive waste management, polar research, environmental science and toxicology, natural disasters, and water science. The National Research Council (NRC) is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering and serves as an independent advisor on scientific and technical questions of national importance. CGER manages the efforts of the following boards: Board on Atmospheric Sciences and Climate (BASC) Board on Earth Sciences and Resources (BESR) Board on Environmental Studies and Toxicology (BEST) Board on Radioactive Waste Management (BRWM) Natural Disasters Roundtable (NDR) Ocean Studies Board (OSB) Polar Research Board (PRB) Water Science and Technology Board (WSTB) Of particular importance to AUV developments is the work performed under the leadership of the OSB. OSB was established by the NRC to advise the Federal government on issues of ocean science, engineering, and policy. In addition to exercising leadership within the ocean community, the OSB undertakes studies at the request of Federal agencies, Congress, or other sponsors, or upon its own initiative. The OSB explores the science, policies, and infrastructure needed to understand and protect coastal and marine environments and resources. The Board provides an open forum for those interested in ocean issues to bring technical and policy concerns for discussion and possible action. A primary responsibility of the Board is to initiate studies and ensure that they are carried out successfully. As appropriate, studies can be developed and overseen jointly with other NRC Boards. In selecting projects, the OSB attempts to be responsive to the requests of sponsors while also engaging in proactive activities related to ocean sciences, engineering, and policy. A recent project completed is “Sea Floor Observatories: Challenges and Opportunities.” The final report entitled, "Illuminating the Hidden Planet: The Future of Sea Floor Observatory Science," discusses the scientific merit of, technical requirements for, and overall feasibility of establishing the infrastructure needed to implement a system of sea floor observatories. Recently, many sea floor observatory programs have been discussed or proposed. This study assesses the extent to which sea floor observatories will address future requirements for conducting multi-disciplinary ocean research and attempt to gauge the level of support for such programs within ocean science and the broader scientific community. This report highlights the use of AUVs in sea floor observatory projects. 60 Review of Autonomous Undersea Vehicle (AUV) Developments OSB ACTIVITIES UNDER DEVELOPMENT e Assessing Ambient Noise in the Ocean with Regard to Potential Impacts on Marine Mammals Carbon Sequestration Science Environmental Information for Naval Use Effects of Climate on Fisheries Environmental Considerations for Deep-Water Drilling Gas Hydrates in the Marine Environment Governance Structures for Publicly Owned Natural Resources Marine Biotechnology: Biosensors, Sentinel Species, and Marine Pharmaceuticals Representing and Reducing Uncertainty in Operational Ocean Models Reference Materials for Ocean Sciences The Role of Stock Enhancement in Fisheries Management Understanding and Managing Coastal Sediment Budgets THE CONSORTIUM FOR OCEANOGRAPHIC RESEARCH AND EDUCATION (CORE) [45] The Consortium for Oceanographic Research and Education (CORE) is an association of U.S. oceanographic research institutions, universities, laboratories, and aquaria organized to advance the science of oceanography. CORE actively supports a wide range of issues and projects in research. The fundamental objective of this activity is to promote continued public and private investment in ocean research and to raise the awareness of the importance of this research to a spectrum of societal needs. Education is a major component of CORE’s mission. Facilitating the formulation of goals, policies, and objectives and providing advice and management for educational and research programs and facilities in oceanography and related fields are paramount. To foster an environment wherein oceanographic science and education are recognized as integral to U.S. policy goals in national security, economic development, quality of life, and education remains one of CORE’s primary objectives. 61 Review of Autonomous Undersea Vehicle (AUV) Developments THE MARINE TECHNOLOGY SOCIETY [46,47] The Marine Technology Society (MTS) is dedicated to serving all people interested in the world's oceans. It is the only professional society committed to every sector of the ocean community: engineers, scientists, policymakers, educators, industry leaders, students, and concerned individuals. The MTS leads all its members to greater information and recognition. MTS is a network with a bounty of benefits. Since its founding in 1963, MTS has been working toward the following goals: e Disseminating marine science and technical knowledge e Promoting and supporting education for marine scientists, engineers, and technicians e Advancing the development of tools and procedures required to explore, study, and further the responsible and sustainable use of the oceans e Providing services that promote a broader understanding of the relevance of the marine sciences to other technologies, arts, and human affairs MTS’s goals are accomplished by a variety of means, including conferences, workshops, committee meetings, and publications. The activities are enhanced by the diversity of the MTS membership, which is comprised of students and professionals involved in business, government, and academia who share an interest in ocean and marine science, engineering, and policy. The combination of the organized activities and the dynamic membership makes MTS a valuable forum for a rich exchange of ideas. The MTS ROV Committee probably has one of the most dynamic pasts of any professional committee of the society. Its growth provides a good indication of the increasingly dynamic role of unmanned vehicles around the world. The parent MTS Undersea Vehicle Committee was essentially a manned submersible committee. Previous chairmen, such as R. McGrattan, John Pritzlaff, Joe Vadus, and R. Frank Busby nurtured it through its dynamic early days. Of particular note are the three MTS publications on manned submersible safety compiled by the Safety Standards Subcommittee led by Pritzlaff. These books were created by icons of the industry, although they did not reference unmanned vehicles, as the world was dominated by manned systems. Unmanned vehicles arrived on the scene, making deeper penetrations into the manned vehicle realm, and the ROV Subcommittee was created in 1978, chaired by Drew Michel, who was followed by Robert Wernli from 1981 through 1991. As ROVs emerged in importance during that period, and with the timely theme of "A Technology Whose Time Has Come," the ROV subcommittee created the first unmanned vehicle conference--ROV '83--held in San Diego, California. Between ROV '83 and '84 conferences, the subcommittee produced the book "Operational Guidelines for Remotely Operated Vehicles," a needed follow-on to the three Pritzlaff-developed books. The ROV conferences and the Guidelines were successful. Along with the growing strength of the subcommittee, the Undersea Vehicle Committee became the largest committee in MTS. ROV '85 was again held in San Diego, and between 1985 and 1986, the Undersea Vehicle Committee again doubled in size to nearly 225 members. Because of the strength of the ROV industry and the size of the ROV committee (nearly twice the size of the 62 Review of Autonomous Undersea Vehicle (AUV) Developments next largest), the ROV Subcommittee was merged with the Undersea Vehicle Committee to become the Undersea Vehicle/ROV Committee. ROV COMMITTEE MISSION “To promote the interchange of technical information between _ industrial, academic, defense, and other organizations on an international basis in the areas of ROVs, undersea robotics and artificial intelligence; provide speakers to academic institutions to increase the participation of students in the society and areas of ROV and undersea technology; produce technical publications related to ROV technology.” The "Operational Effectiveness of Unmanned Underwater Systems" CD-ROM is now available from MTS. Robert Wernli of First Centurion Enterprises announced that the final product is 700 pages with 390 photographs, charts, and diagrams. For a demonstration of this CD-ROM see www.rov.org/rovdemo. The CD-ROM contains details about unmanned systems and their expected performance, including full descriptions and specifications, how they operate, where they are operating and how successfully, and what they can be expected to do in the future. The product has full CD-ROM search capability for key words in the basic text to related text and databases, as well as related photos and data sheets. Also included is a bibliography of past years of ROV/UI conference manuscripts, links to hundreds of ROV technology World Wide Web sites and a committee membership directory, including Internet addresses. The product is a truly interactive CD-ROM that offers needed information, accurately and rapidly. THE NATIONAL UNDERSEA RESEARCH PROGRAM OF NOAA [48] Progress in oceanography in the past quarter century has been greatly assisted by the development of undersea technology. The National Undersea Research Program (NURP), within NOAA, provides a unique national service by providing undersea scientists with the tools and expertise they need to work in the undersea environment. NOAA equips scientists with submersibles, ROVs or AUVs, mixed gas diving gear, and underwater laboratories and observatories. NOAA research programs cover a range of undersea environments from the shoreline to the deep sea, capturing nearly all the scientific disciplines. A compendium of NURP's scientific studies illustrates the significance of gathering information from the ocean. 63 Review of Autonomous Undersea Vehicle (AUV) Developments NURP's science programs are carried out by a series of regional centers around the nation. Projects are selected by peer-review, thus, opening up opportunities for undersea support to all of the nation's science community. Presently, the regional centers include (figure 28): e Caribbean: Perry Foundation's Caribbean Marine Research Center e Hawaii _ and the Western Pacific: University of Hawaii at Manoa, Hawaii Undersea Research Laboratory Mid-Atlantic Bight: Rutgers University West Coast and Polar Regions: University of Alaska at Fairbanks North Atlantic and Great Lakes: University of Connecticut-Avery Point Southeast and Gulf of Mexico: University of North Carolina at Wilmington GG North Anlantic & Great Lakes C7 Somheastem US. & the Gulf of Medco C7 Caribbem CJ Hywaii & the Pacific C7) Vest Coast & Polar Regiors Figure 28. NURP Regional Centers NURP operates undersea robots or remotely operated vehicles ROVs that are deployed from ships of opportunity. NURP provides access to a variety of ROVs, some leased and some owned by the program. NURP's ROVs have worked from the tropics to the Arctic and Antarctic. The manipulator arm of the Kraken, a Deep Sea Systems International MAXRover MK1, the largest of the center's ROVs with a depth capability of 940 meters (3,000 feet), works like the arms and hands of a human body to pick up specimens and place them in containers. Kraken's suction samplers collect algae, animals, and sediments. Three video cameras on the Kraken wide-angle, close-up, low-light, and 35-mm-film camera with a flash allow for high-resolution imaging and photography. A laser determines the size of objects underwater, and a scanning sonar uses sound to view objects and organisms outside the range of the cameras. NURP also operates smaller ROVs like the MiniRover and the Phantom S-2, which carry less weight and 64 Review of Autonomous Undersea Vehicle (AUV) Developments equipment in their dives to 230 meters (750 feet), but require only one support person above water. AUVs are the most recent class of exploration technology. Independent of the surface, battery powered, and controlled by computers using various levels of artificial intelligence, these vehicles are programmed to carry out various underwater survey tasks. The REMUS AUV (figure 29) was developed by Woods Hole Oceanographic Institution for NURP's Mid-Atlantic Undersea Research Center to carry out wide-area continental shelf surveys. Designed for coastal monitoring and multiple vehicle survey operations, REMUS can operate in fresh or salt water. Though small in size, Figure 29. REMUS the vehicle is currently configured to support a variety of sensor packages. LONG-TERM ECOSYSTEM OBSERVATORY [49] An innovative approach is being demonstrated by Rutgers University and the Woods Hole Oceanographic Institution at a Long-term Ecosystem Observatory (LEO-15) at a 15-meter (48 foot) depth on the inner continental shelf of New Jersey. Most events in the ocean are missed because sensors are not in the ocean environment to continuously recording what happens there. As a result of this deficiency, LEO-15 is now the focus of a broad spectrum of research sponsored by NURP's Mid-Atlantic Research Center. Since its inception, more than 50 projects at LEO-15 have been supported with funding from the NSF, NURP, and the National Ocean Partnership Program. A dozen different sensors at LEO-15 provide real-time information (figure 30). LEO's Web site receives real-time data from satellites and the in situ sensors. An electro-fiber optic cable runs along the bottom of the ocean to two submerged nodes. The nodes are equipped with profiling instruments that move up and down in the water column, measuring temperature, salinity, and depth. Scientists can control the nodes via the Internet onshore. To get an idea of ocean events occurring between these nodes, two AUVs have been designed to travel between them measuring different oceanic processes. LEO's capabilities will eventually extend to sites at 750 meters (2,400 feet) and at 2,500 meters (8,000 feet) offshore. Extensive studies have already taken place at the 2,500-meter site where six years of intensive sewage sludge dumping occurred. Having an observatory there would facilitate the study of the long-term effects of deep-ocean dumping on the ecosystem. This is an important consideration in light of the pressing need to find alternative sources for waste disposal. The development of other coastal observatories in places like Chesapeake and Monterey Bays, on Georges Bank, or in extreme environments, such as along mid-oceanic ridges, could also be sparked by LEO-15. 65 Review of Autonomous Undersea Vehicle (AUV) Developments Long-term Ecosystem Observatory (LEO-15) Figure 30. Long-term Ecosystem Observatory (LEO-15) 66 Review of Autonomous Undersea Vehicle (AUV) Developments THE DEEP SUBMERGENCE SCIENCE COMMITTEE OF UNOLS [50,51] The DEep Submergence Science Committee (DESSC) is a standing committee of the University National Oceanographic Laboratory System (UNOLS). DESSC provides advisory responsibilities for the National Deep Submergence Facility that includes ALVIN, Jason-Medea, ARGO-II, and the 120-kHz Side-Looking Sonar. 67 Review of Autonomous Undersea Vehicle (AUV) Developments AUV MARKET FORECAST [52,53,54] Sales of UUVs are expected to climb from $100 million in 2000 to over $330 million in 2004, and total $1.2 billion over the period. But growth in operational revenues during the same period will be greater, from $500 million to nearly $930 million, for a total of $3.5 billion (excluding support vessels). The revenues found in figure 31 are part of the results of a major new study, “The World UUV Report,” on business prospects for Work-Class ROVs, and the “new” technology of AUVs launched by leading oil and marine analysts Douglas-Westwood at the Offshore Technology Conference in Houston. UUV operations Revenues ($ million) 900 | WAUVs 800 | @Work-Class ROVs $ million . 0 sae e pee eS 2000 2001 2002 2003 2004 Figure 31. Strong Growth Forecast in UUV Market Source: The World UUV Report (Douglas-Westwood Limited) Over 3,000 ROVs of various types have been built to date, but the report concentrates on the high-price, high-earning Work-Class ROVs. There is currently a world fleet of 478 units for which the offshore oil and gas industry is the biggest customer. According to the report, the year 2000 represents a cyclical low for the UUV manufacturing industry caused by the earlier oil price fall. In 1999, 61 Work-Class ROVs were delivered, but in 2000 only 38 deliveries were expected. However, with firm oil prices and growing deep-water activity, deliveries should climb to 118 units in 2004. Over the period, the report’s base-case analysis shows the Work-Class ROV fleet growing by nearly 50%. This growing fleet will require an increasing expenditure on ancillary equipment and replacement items with an estimated market value of $468 million over the five-year period. While the offshore oil industry has been though a cyclical low, the submarine telecom cables sector has boomed. UUVs are used to survey, trench, and maintain cables, and the authors expect that cable work will account for 34% of UUV operational revenues over the period. 68 Review of Autonomous Undersea Vehicle (AUV) Developments According to report joint author, John Westwood, the major technical challenges are “to reduce costs of ownership and to provide cost-effective systems for operations in ever-increasing water depths. One approach is the use of all-electric ROVs (most existing machines are electro- hydraulic systems) involving aerospace standard power systems and a total redesign to reduce component count and the numbers of electrical connections exposed to seawater.” AUVs, the new kids on the block, are true pre-programmed robots, increasingly capable of carrying out underwater survey and other missions without direct human control. AUVs entered commercial service in 2000, and if industry expectations are achieved, the authors believe that annual sales could grow to over 30 units in 2004 and AUVs account for 20% of UUV operations revenues. Two thirds of AUV revenues are expected from their use in seabed survey. (See Table 12.) Financing UUV development remains a problem. Despite the growth of the telecommunications market, the major end-users of UUVs are the oil and gas companies. Their corporate objectives preclude most of them from direct investments in the development of new technology, regarding this as the role of the technology providers — the underwater service contractors. Table 12. Report Projections of Growth Operations ($m) 2000 2001 2002 2003 2004 00-04 Work-Class ROVs 501 565 695 747 817 3325 AUVs 2 9 26 59 112 207 total $m 503 574 720 806 928 3532 OBSERVATIONS AND RECOMMENDATIONS The number of UUVs of various types has increased each year over the period of this report. The spectrum of vehicles includes those for military, scientific, and industrial uses. The complexity of missions, depth, range, and mission duration has increased over this period. Launch and recovery considerations, less glamorous than the UUVs themselves, have not received the deserved emphasis necessary to elevate the operational efficiency of UUV systems. Docking stations, designed to download data from UUVs, recharge batteries, and program the UUV for its next mission, are advancing quickly. Industry, who earlier postponed interest in UUVs until they were confident in the technology, appears now to be reasonably comfortable in applying UUVs as tools. UUVs are now in use commercially in survey work. Commercial acceptance of UUVs has begun! The future for UUV use is great. Sensors and energy systems demand attention to speed the technical advances and operational uses of UUVs. 69 Review of Autonomous Undersea Vehicle (AUV) Developments Bibliography 1. Mooney, J.B. et al., 1996. National Research Council Report, Undersea Vehicles and National Needs. National Academy Press 2 National Research Council, Naval Studies Board, 1997. Technology for the United States Navy and Marine Corps, 2000-2035: Becoming a 21st Century Force, http://www.nas.edu/cpsma/nsb/tfnf.htm 3, Dunn, P.M., 28 Dec 1999, The Navy Unmanned Undersea Vehicle (UUV) Master Plan, Naval Undersea Warfare Center 4. CAPT Fiebeg, June 1998, Brief slides on The Navy's Unmanned Undersea Vehicle (UUV) Program 5: Near-Term Mine Reconnaissance System (NMRS) Office of Naval Research Web Page of 4 Sep 1997. http://www.onr.navy.mil/sci tech/ocean/jcm/nmrs.htm 6. Federation of American Scientist Web Page of 1 Jan 1999. http://www.fas.org/man/dod- 101/sys/ship/weaps/nmrs.htm ie Federation of American Scientist Web Page of 1 Jan 1999 http://www.fas.org/man/dod- 101/sys/ ship/weaps/Imrs.htm 8. The Boeing Company Web Page of 2000. http://www. boeing.com/defense- space/infoelect/Imrs/ 9. Naval Postgraduate Research Center for AUV Research Web Page, http://www.cs.nps.navy.mil/research/auv/about_auv.html 10. SonTeck Web Page of 3 June 2000. http://www.sontek.com/apps/auv-rov-uuv/advo- nps/advo-nps.htm 11. Walton, J., Nov 1992. NRaD Technical Report 1527, Advanced Unmanned Search System (AUSS) Testbed - Search Demonstration Testing 12. Jones, H.V., Nov 1992. NRaD Technical Report 1528, Advanced Unmanned Search System (AUSS) Description 13. | Uhrich, R.W. & Walton, S.J.,. Nov 1992. NRaD Technical Report 1530, Deep-Ocean Search Inspection: Advanced Unmanned Search System (AUSS) Concept of Operation 14. | McCracken, H.B., Nov 1992. NRaD Technical Report 1533, Advanced Unmanned Search System (AUSS) Supervisor Command, Control, and Navigation 70 Review of Autonomous Undersea Vehicle (AUV) Developments 15. Smith, K.L., Jr., R.C. Glatts, R.J. Baldwin, A.H. Uhlman, R.C. Horn, C.E. Reimers and S. E. Beaulieu. 1997. An autonomous, bottom-transecting vehicle for making long time-series measurements of sediment community oxygen consumption to abyssal depths, Limnol. Oceanogr., 42(7):1601-1612. 16. Ken Smith Laboratory Website, http://smithlab.ucsd.edu/ 17. | HUGIN 3000 Brochure, Kongsberg Simrad As 18. | Kongsberg Simrad As Website, http://www.kongsberg-simrad.com 19. Northcutt, J.G., Kleiner, A.A. & Chance, T.S., May 2000. A High-Resolution Survey AUV, 2000 Offshore Technology Conference Paper OTC 12004 20. Chance, T.S., Kleiner, A.A., Northcutt, J.G., 2000. The Autonomous Underwater Vehicle (AUV): A Cost-Effective Alternative to Deep-Towed Technology, Integrated Coastal Zone Management 6th Ed. (pp. 65-69) 21. C&C Technologies, Inc., Web Page http://www.cctechnol.com/auy.htm Ze. MIT Web Page. http://auvserv.mit.edu/Odysseyllb.html 23. Nadis, S. 28 March 1997. Real-Time Oceanography Adapts to Sea Changes, Science, Vol. 275 (pp. 1881-82) 24. Nadis, S. 28 March 1997. Robotic Subs for Rapid-Response Science, Science, Vol. 275 (p. 1881) 25. Kreider, J.R, February 1997. UUVs for Underwater Work - Innovation or High Tech Toy?, Sea Technology (pp. 51-57) 26. Levi, C., 29 January 1997. MIT Sea Grant's Underwater Robot to Search for Giant Squid, MIT Tech Talk 27. Niller, E., 19 February 1997. Going Deep to Look for Real Live Giant Squid, The San Diego Union-Tribune 28. Levi, C., Fall/Winter 1996. Science at the Front, MIT Sea Grant Nor'easter (pp. 16-19) 29. Bellingham, J.G., August 1997. New Oceanographic Uses of Autonomous Underwater Vehicles, DRAFT submitted to Marine Technology Review 30. MIT Web Page http://seagrant.mit.edu/loops.html 31. | Lauerman, J.F., 1999. The Little Yellow Sub That Could: Evolving Technologies Plumb the Oceans' Depths, MIT Sea Grant Nor'easter 71 Review of Autonomous Undersea Vehicle (AUV) Developments 32. MIT Web Page hftp://auvserv.mit.edu/reports/HLbjg99.htm 33. MIT Web Page http://auvserv.mit.edu/aosn.htm 34. SPAWAR Web Page of 10 December 1999. http://www.nosc.mil/robots/undersea/dssn/dssn.html 35. Bellingham J.G., Schmidt H., & Chryssostomidis C., AOSN MURI., Real-Time Oceanography With Autonomous Ocean Sampling Networks: A Center for Excellence, MIT Sea Grant Program ONR Annual Report, also on Web Page http://auvserv.mit.edu/MURI/annual- report98.htm 36. MIT Web Page http://auvserv.mit.edu/CETUS.html 37. WHOI Web Page http://adcp.whoi.edu/REMUS/index.html 38. |WHOI Web Page http://www.marine.whoi.edu/ships/auvs/abe_description.htm 39. FAU Web Site http://www.oe.fau.edu/research/ams.html 40. AUSI Web Site http://www.ausi.org/ 41. AUSI, 21-22 January 2000, Autonomous Undersea Systems Institute Board of Directors Meeting 42. AUSI, 31 March 1998, A Strategic Plan for A AUS Consortium for the Research, Development, Utilization and Commercialization of Autonomous Undersea Vehicle Systems Technology, Version 1.4(rev) 43. | AUSI Annual Report for Fiscal Year 1999 44. CGER Web Site hftp://www4.nas.edu/cger/cger.nsf 45. CORE Web Site http://core.cast.msstate.edu/ 46. MTS Web Site http://www.mtsociety.org/ 47. MTS ROV Committee Web Site http://www.rov.org/ 48. NOAA National Undersea Research Center Web Site http://www.oar.noaa.gov/oceans/ocean_nurp.html#start 49. NOAA NURC Web Page http://marine.rutgers.edu/nurp/mabnurc.html 50. | UNOLS Web Site http://www.unols.org/ 72 Review of Autonomous Undersea Vehicle (AUV) Developments 51. UNOLS DESSC Web Site http://www.unols.org/dessc/ 52. Westwood, J., 16 September 1999. Future Prospects for AUVs, presented Maridan 'PING' Symposium in Copenhagen 53. Douglas & Westwood, 1 May 2000. Strong Growth Forecast in Underwater Vehicles Market, Douglas-Westwood Limited News Release 54. Westwood, J., 2000. Future Markets for UUVs, Douglas-Westwood Associates 73 a