DOCSLIB.ORG

Introduction of a Small, Submersible Robot to Perform the Data Collection in Order to Achieve Some Level of Autonomous Control of a Task with Some Degj:Ee of Autonomy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Introduction of a Small, Submersible Robot to Perform the Data Collection in Order to Achieve Some Level of Autonomous Control of a Task with Some Degj:Ee of Autonomy .Autmnms1hnHrlSuneying<i~Gft'fltBaniTRaf Stlfan\Villianl;,PaulNewlmn,Som~ ,Jutio~HughDummt.Whyte Amtralian CearefirReId RoOOtia; University ofSydrey Abstract This paper presents work done as a step towards fully autonomous navigation using the Oberon submersible developed at the University of Sydney. The Oberon team is currently working on a project proposed by the Australian Institute of Marine Sciences (.AIMS).This orlaaisation is surveying sections of the Great Barrier Reef in order to study the growth and propagation of coral. They send a diver to record vioeo transects of the reef while holoing an unoerwater video camera at a height of approximately 30cm above the coral. The video images are then analysed to determine the growth and density of Figure 1 - Diver taking a visual transect of the reef various coral structures. This presents an ideal opportunity for the introduction of a small, submersible robot to perform the data collection In order to achieve some level of autonomous control of a task with some degJ:ee of autonomy. The task robotic vehicle the context in which the robot will be used must be well understood. The environment in which it has been divided into two sub-tasks: maintaining an~ altitude above the reef and following the linear will operate the. tasks that it will be required to undertake will all impact heavily on the sensors and transect. Independent behaviours and decoupled controllers provide a modular means of control schemes that are adopted. accomplishing these tasks. Both a sonar-based In the early development of any robotic system, approach and vision are being considered as it is important to find tasks that are achievable and at the methods with which to guide the robot along its same time provioe enough complexity to be interesting. intended course. The task that has been. proposed by the AIMS group has proven to be an ioeal one with which to begin work towards a truly autonomous submersible robot. It Introduction provides few restrictions on the method with which the Keeping a scientifically rigorous track of change on the task will be accomplished but sets clear goals to be Great Barrier Reef is an essential component of good reef achieved. management. ~e Great Barrier Reef survey project of The task itself can be divided up into two distinct the Australian Institute of Marine Sciences (AIMS), problems that must be solved - maintaining a fixed height initiated in 1991, is desiped to provide long-term above the reef and traversing the linear transect. Separate quantitative geographic data about corals, algae and behaviours and controllers are used to develop ·and marine life over the extent of the Great Barrier Reef. This accomplish each ofthese sub-tasks independently. It must data is an information source for the Great Barrier Reef have a stand-off behaviour that allows it to maintain a Marine Park Authority as well as a basis for studies of fixed altitude above the reef while it follows the transect abundance and population change in selected org~isms and collects data for later off-line analysis. on a large geographic scale. The robot must also have the ability to traverse AIMS divers are currently required to perform the section ofreef in a straight line and to be able to repeat broadscale surveys of coral densities and censuses of its path on subsequent missions. Without absolute .corals and marine life that form the basis for status position data available to the sub, it is necessary to sense reports. A set of reefs is monitored on an annual basis; features in the environment and to deduce the vehicle's others are sampled when specific issues arise. Currently, position from these features. There are a number of ways visual transect information is recorded using underwater in which this could be accomplished and two methods are video cameras held above the reef as the diver follows a currently being pursued - visual servoing on a line laid prescribed path (Figure 1). Subsequent analysis of the out along the coral and using sonar to navigate relative to recorded sequences is used to determine coral diversity targets mounted along the line. and gJ:owth patterns. This project presents an interesting By decoupling the control into the separate opportunity for the introduction of a small, autonomous subproblems of altitude control and line following, the subsea robot to perform the reef-surveying task. individual controller desian is greatly simplified. The behaviours to be exhibited by the robot can be developed independently of one another and later combined to allow the robot to meet its goals. 16 the wide beam of the sonar. The Oberon Vehicle The second sonar is a Tritech SeaKing. This sonar has two narrow beam sonar heads and is considerably The AUV project at the University of Sydney has focused faster than the Imagenex unit. It is mounted on top of the on the development of a mid-size submersible robotic sub and is used to scan the environment in which the sub vehicle called Oberon (Figure 2). This device is intended is operating. It can achieve 3600 scan rates on the order primarily as a research platform upon which to test a of 0.25 Hz. The information that is returned from this variety of sensing strategies and control methods. sonar is used to maintain a feature map of the. environment. Internal Sensors A pressure sensor is used to measure the depth of the sub below the surface of the ocean. This sensor provides a voltage signal proportional to the pressure and is sampled at high speeds by an analogue to digital· converter on the embedded controller. This sensor is used to control the depth ofthe sub. An Andrews Laser Gyro has been included in the Oberon robot to allow the robot's orientation to be determined. This sensor provides fairly acc.ate heading information and is used to control the heading of the sub. A tri-axial, Crossbow accelerometer is also present. Since the Oberon is a relatively slow-moving vehicle, this is used primarily as a tilt sensor. The Figure 2 -the 0beron· vehicle accelerations experienced by the sub are negligible and the accelerometers can be used to measure the inclination of the sub relative to the gravitational field. Embedded controller At the heart of the control of the robot is an embedded Camera control system. At the time of the experiments reported A small Pulnix camera is· used to provide video feedback here, the Oberon vehicle was controlled using a series of of the underwater scenes in which the robot operates. transputers. The Oberon robot has since been upgraded to This is a colour camera and sends the video signal to the use a CompactPCI system running Windows NT that surface via the tether. A Matrox Meteor card is then used interfaces directly to the hardware and is used to control to acquire the video signal for further image processing. the motion of the robot and to acquire the sensor data. This data is collated and sent to the surface where a Thrusters network of computers are used for further data processing There are currently 5 thrusters on the Oberon vehicle. and to display the information to provide the user with Three of these are oriented in the vertical direction while feedback about the state ofthe sub. the remaining two are directed horizontally. This gives A number of processes have been developed to the vehicle the ability to move itself up and down, control accomplish the tasks of gathering data from the robot's its yaw, pitch and· roll and move forwards and backwards. sensors, processing this data and reasoning about the Side to side motion is not possible with this thruster course of action to be taken by the robot. These processes arrangement. communicate asynchronously via a TCPIIP socket-based interface. Communications between the computers at the Solving the Problem surface and the sub are via a tether. This tether also provides power to the robot, a video cable for transmitting MaiDtaimDgAltitude abo'¥e Sea Floor video data and a serial line for control of the camera The firSt task that must be accomplished in order·to realise pan/tilt unit. While some effort might have been spent on the goals set out in this project is :the ability to maintain eliminating the tether, it was felt that the development of the robot at a certain altitude· above -the ·seafloor. The the navigational techniques was of more immediate robot must be able to detect the ground and maintain its interest. height in order to avoid colliding with the coral specimens (Figure 3). Sonar This task has been accomplished using. a Sonar is the primary sensor of·interest for the Oberon combination of the lmagenex Sonar and the depth sensor. project. Navigating autonomously underwater using these The robot maintains a particular depth using a simple PIO sonar sensors is one of the ultimate goals of the project controller based on the measurements returned by the [Newman and Durrant-Whyte, 1997]. There are currently depth sensor. The Sonar is then used to periodically two sonars on the robot. determine the desired depth by finding the altitude of the An Imagenex sonar unit has been mounted at the robot. front of the vehicle. It is positioned such that its scanning head can be used as a forward and downward looking beam. This enables the altitude above the sea floor as well as the proximity of obstacles to be determined using 17 The x-y coordinates of the ith pixel (xj, Yi) found are then fitted to a straight line using a linear regression algorithm (Equation 1).
Load more

Recommended publications
  • Winds, Waves, and Bubbles at the Air-Sea Boundary
    JEFFREY L. HANSON WINDS, WAVES, AND BUBBLES AT THE AIR-SEA BOUNDARY Subsurface bubbles are now recognized as a dominant acoustic scattering and reverberation mechanism in the upper ocean. A better understanding of the complex mechanisms responsible for subsurface bubbles should lead to an improved prediction capability for underwater sonar. The Applied Physics Laboratory recently conducted a unique experiment to investigate which air-sea descriptors are most important for subsurface bubbles and acoustic scatter. Initial analyses indicate that wind-history variables provide better predictors of subsurface bubble-cloud development than do wave-breaking estimates. The results suggest that a close coupling exists between the wind field and the upper-ocean mixing processes, such as Langmuir circulation, that distribute and organize the bubble populations. INTRODUCTION A multiyear series of experiments, conducted under the that, in the Gulf of Alaska wintertime environment, the auspices of the Navy-sponsored acoustic program, Crit­ amount of wave-breaking activity may not be an ideal ical Sea Test (CST), I has been under way since 1986 with indicator of deep bubble-cloud formation. Instead, the the charter to investigate environmental, scientific, and penetration of bubbles is more closely tied to short-term technical issues related to the performance of low-fre­ wind fluctuations, suggesting a close coupling between quency (100-1000 Hz) active acoustics. One key aspect the wind field and upper-ocean mixing processes that of CST is the investigation of acoustic backscatter and distribute and organize the bubble populations within the reverberation from upper-ocean features such as surface mixed layer. waves and bubble clouds.
    [Show full text]
  • Wetsuits Raises the Bar Once Again, in Both Design and Technological Advances
    Orca evokes the instinct and prowess of the powerful ruler of the seas. Like the Orca whale, our designs have always been organic, streamlined and in tune with nature. Our latest 2016 collection of wetsuits raises the bar once again, in both design and technological advances. With never before seen 0.88Free technology used on the Alpha, and the ultimate swim assistance WETSUITS provided by the Predator, to a more gender specific 3.8 to suit male and female needs, down to the latest evolution of the ever popular S-series entry-level wetsuit, Orca once again has something to suit every triathlete’s needs when it comes to the swim. 10 11 TRIATHLON Orca know triathletes and we’ve been helping them to conquer the WETSUITS seven seas now for more than twenty years.Our latest collection of wetsuits reflects this legacy of knowledge and offers something for RANGE every level and style of swimmer. Whether you’re a good swimmer looking for ultimate flexibility, a struggling swimmer who needs all the buoyancy they can get, or a weekend warrior just starting out, Orca has you covered. OPENWATER Swimming in the openwater is something that has always drawn those types of swimmers that find that the largest pool is too small for them. However open water swimming is not without it’s own challenges and Orca’s Openwater collection is designed to offer visibility, and so security, to those who want to take on this sport. 016 SWIMRUN The SwimRun endurance race is a growing sport and the wetsuit requirements for these competitors are unique.
    [Show full text]
  • Fusion System Components
    A Step Change in Military Autonomous Technology Introduction Commercial vs Military AUV operations Typical Military Operation (Man-Portable Class) Fusion System Components User Interface (HMI) Modes of Operation Typical Commercial vs Military AUV (UUV) operations (generalisation) Military Commercial • Intelligence gathering, area survey, reconnaissance, battlespace preparation • Long distance eg pipeline routes, pipeline surveys • Mine countermeasures (MCM), ASW, threat / UXO location and identification • Large areas eg seabed surveys / bathy • Less data, desire for in-mission target recognition and mission adjustment • Large amount of data collected for post-mission analysis • Desire for “hover” ability but often use COTS AUV or adaptations for specific • Predominantly torpedo shaped, require motion to manoeuvre tasks, including hull inspection, payload deployment, sacrificial vehicle • Errors or delays cost money • Errors or delays increase risk • Typical categories: man-portable, lightweight, heavy weight & large vehicle Image courtesy of Subsea Engineering Associates Typical Current Military Operation (Man-Portable Class) Assets Equipment Cost • Survey areas of interest using AUV & identify targets of interest: AUV & Operating Team USD 250k to USD millions • Deploy ROV to perform detailed survey of identified targets: ROV & Operating Team USD 200k to USD 450k • Deploy divers to deal with targets: Dive Team with Nav Aids & USD 25k – USD 100ks Diver Propulsion ---------------------------------------------------------------------------------
    [Show full text]
  • Low-Frequency Active Towed Sonar
    LOW-FREQUENCY ACTIVE TOWED SONAR Full-feature, long-range, low-frequency active and passive variable depth sonar (VDS) The Low-Frequency Active Sonar (LFATS) system is used on ships to detect, track and engage all types of submarines. L3Harris specifically designed the system to perform at a lower operating frequency against modern diesel-electric submarine threats. FEATURES > Compact size - LFATS is a small, > Full 360° coverage - a dual parallel array lightweight, air-transportable, ruggedized configuration and advanced signal system processing achieve instantaneous, > Specifically designed for easy unambiguous left/right target installation on small vessels. discrimination. > Configurable - LFATS can operate in a > Space-saving transmitter tow-body stand-alone configuration or be easily configuration - innovative technology integrated into the ship’s combat system. achieves omnidirectional, large aperture acoustic performance in a compact, > Tactical bistatic and multistatic capability sleek tow-body assembly. - a robust infrastructure permits interoperability with the HELRAS > Reverberation suppression - the unique helicopter dipping sonar and all key transmitter design enables forward, aft, sonobuoys. port and starboard directional LFATS has been successfully deployed on transmission. This capability diverts ships as small as 100 tons. > Highly maneuverable - own-ship noise energy concentration away from reduction processing algorithms, coupled shorelines and landmasses, minimizing with compact twin-line receivers, enable reverb and optimizing target detection. short-scope towing for efficient maneuvering, fast deployment and > Sonar performance prediction - a unencumbered operation in shallow key ingredient to mission planning, water. LFATS computes and displays system detection capability based on modeled > Compact Winch and Handling System or measured environmental data. - an ultrastable structure assures safe, reliable operation in heavy seas and permits manual or console-controlled deployment, retrieval and depth- keeping.
    [Show full text]
  • Sonar for Environmental Monitoring of Marine Renewable Energy Technologies
    Sonar for environmental monitoring of marine renewable energy technologies FRANCISCO GEMO ALBINO FRANCISCO UURIE 350-16L ISSN 0349-8352 Division of Electricity Department of Engineering Sciences Licentiate Thesis Uppsala, 2016 Abstract Human exploration of the world oceans is ever increasing as conventional in- dustries grow and new industries emerge. A new emerging and fast-growing industry is the marine renewable energy. The last decades have been charac- terized by an accentuated development rate of technologies that can convert the energy contained in stream flows, waves, wind and tides. This growth ben- efits from the fact that society has become notably aware of the well-being of the environment we all live in. This brings a human desire to implement tech- nologies which cope better with the natural environment. Yet, this environ- mental awareness may also pose difficulties in approving new renewable en- ergy projects such as offshore wind, wave and tidal energy farms. Lessons that have been learned is that lack of consistent environmental data can become an impasse when consenting permits for testing and deployments marine renew- able energy technologies. An example is the European Union in which a ma- jority of the member states requires rigorous environmental monitoring pro- grams to be in place when marine renewable energy technologies are commis- sioned and decommissioned. To satisfy such high demands and to simultane- ously boost the marine renewable sector, long-term environmental monitoring framework that gathers multi-variable data are needed to keep providing data to technology developers, operators as well as to the general public. Technol- ogies based on active acoustics might be the most advanced tools to monitor the subsea environment around marine manmade structures especially in murky and deep waters where divining and conventional technologies are both costly and risky.
    [Show full text]
  • Doppler Sonar Current Indicator 8
    DOPPLER SONAR CURRENT INDICATOR 8 Model High-performance current indicator displays accurate speed and current data at five depth layers on a 10.4" color TFT or virtually any VGA monitor utilizing a Black Box system www.furuno.com Obtain highly accurate water current measurements using FURUNO’s reliable acoustic technology. The FURUNO CI-68 is a Doppler Sonar Current The absolute movements of tide Indicator designed for various types of fish and measuring layers are displayed in colors. hydrographic survey vessels. The CI-68 displays tide speed and direction at five depth layers and ship’s speed on a high defi- nition 10.4” color LCD. Using this information, you can predict net shape and plan when to throw your net. Tide vector for Layer 1 The CI-68 has a triple-beam emission system for providing highly accurate current measurement. This system greatly reduces the effects of the Tide vector for Layer 2 rolling, pitching and heaving motions, providing a continuous display of tide information. When ground (bottom) reference is not available Tide vector for Layer 3 acoustically in deep water, the CI-68 can provide true tide current information by receiving position and speed data from a GPS navigator and head- ing data from the satellite (GPS) compass SC- 50/110 or gyrocompass. In addition, navigation Tide vector for Layer 4 information, including position, course and ship ’s track, can also be displayed The CI-68 consists of a display unit, processor Tide vector for Layer 5 unit and transducer. The control unit and display unit can be installed separately for flexible instal- lation.
    [Show full text]
  • Transducers Recommended by Garmin
    TRANSDUCER SELECTION 2021 GUIDE CHOOSING THE RIGHT TRANSDUCER PANOPTIX LIVESCOPE™ There are several types of sonar available, each with special capabilities. And each requires a different transducer to work most effectively. For optimum performance, it is very important to match the transducer to your device’s sonar. To start, make sure the transducer you are buying pairs with your unit, and determine what type of sonar technology you would like to add. Read through each section to learn more about the sonar technologies and transducers recommended by Garmin. Our award-winning Panoptix LiveScope sonar brings real-time scanning sonar to life. It shows highly detailed, easy-to-interpret live scanning sonar images of structure, bait and fish swimming below and around your boat in real time, even when your boat SONAR TECHNOLOGY // PAGE 3 ADDITIONAL TRANSDUCERS // PAGE 24 is stationary. • Panoptix Livescope™ • Transom Mount Full capabilities are available with the Panoptix LiveScope • Panoptix Livescope™ Perspective • Thru-hull Traditional System (see below). The Panoptix LiveScope™ LVS12 transducer ® Mode Mount provides an economical solution for your GPSMAP 8600xsv • Thru-hull CHIRP Traditional chartplotter — without the need for a black box -- with 30-degree • Panoptix™ All-seeing Sonar • In-hull 2018 forward and 30-degree down real-time scanning sonar views. • Scanning Sonar System: UHD • Pocket Mount Part no: 010-02143-00 LVS12 • Scanning Sonar System: CHIRP Sonar THREE MODES IN ONE TRANSDUCER ACCESSORIES AND SENSORS // PAGE 32 THE RIGHT MOUNTING // PAGE 10 PANOPTIX LIVESCOPE™ DOWN • Accessories • In-hull Mount • Smart Sensors • Kayak In-hull • NMEA 2000® • Trolling Motor Mount • Transom Mount • Thru-hull Mount Live, easy-to-interpret scanning sonar images of structure and swimming fish in incredible detail below your Panoptix LiveScope LVS12 Down GARMIN TRANSDUCERS // PAGE 12 boat — up to 200’.
    [Show full text]
  • Effects of Ocean Thermocline Variability on Noncoherent Underwater Acoustic Communications
    Portland State University PDXScholar Electrical and Computer Engineering Faculty Electrical and Computer Engineering Publications and Presentations 4-2007 Effects of Ocean Thermocline Variability on Noncoherent Underwater Acoustic Communications Martin Siderius Portland State University, [email protected] Michael B. Porter HLS Research Corporation Paul Hursky HLS Research Corporation Vincent McDonald HLS Research Corporation Let us know how access to this document benefits ouy . Follow this and additional works at: http://pdxscholar.library.pdx.edu/ece_fac Part of the Electrical and Computer Engineering Commons Citation Details Siderius, M., Porter, M. B., Hursky, P., & McDonald, V. (2007). Effects of ocean thermocline variability on noncoherent underwater acoustic communications. Journal of The Acoustical Society of America, 121(4), 1895-1908. This Article is brought to you for free and open access. It has been accepted for inclusion in Electrical and Computer Engineering Faculty Publications and Presentations by an authorized administrator of PDXScholar. For more information, please contact [email protected]. Effects of ocean thermocline variability on noncoherent underwater acoustic communications ͒ Martin Siderius,a Michael B. Porter, Paul Hursky, Vincent McDonald, and the KauaiEx Group HLS Research Corporation, 12730 High Bluff Drive, San Diego, California 92130 ͑Received 16 December 2005; revised 14 December 2006; accepted 30 December 2006͒ The performance of acoustic modems in the ocean is strongly affected by the ocean environment. A storm can drive up the ambient noise levels, eliminate a thermocline by wind mixing, and whip up violent waves and thereby break up the acoustic mirror formed by the ocean surface. The combined effects of these and other processes on modem performance are not well understood.
    [Show full text]
  • Table Is Set for ICC's Irish Festival
    June 2013 Boston’s hometown VOL. 24 #6 journal of Irish culture. $1.50 Worldwide at All contents copyright © 2013 Boston Neighborhood News, Inc. bostonirish.com Atlantic Steps, which takes the stage on the final day of the Boston Irish Festival, showcases the story of Irish dance. Table is set for ICC’s Irish Festival By Sean Smith competitions, an Irish bread An Coimisiun, North American its sometimes gritty, sometimes among the cast of Atlantic Special to the BiR baking contest, children and Feis Commission and NAFC saucy, sometimes angry, always Steps, an international-touring Performances by Eileen Ivers family amusements, genealogy New England Region President loud’n proud version of Irish adaptation by Brian Cunning- & Immigrant Soul, Black 47, consultations, and appearances Pat Watkins. rock, flavored with folk as well ham of the Irish show “Fuaim and Atlantic Steps highlight by authors of books related to Kicking off the festival on as reggae, jazz, and hip-hop to Chonamara,” which chronicles this year’s Boston Irish Festival, Irish and Irish-American his- Friday evening, June 7, at 8 create an unabashed working- the story of sean-nos, Ireland’s which will take place June 7-9 tory, culture and literature. o’clock, will be Grammy win- class urban sound. Fronted by oldest dance form, portrayed at the Irish Cultural Centre of This year also will see the ner and nine-time all-Ireland lead singer, writer and guid- through the music, song, dance, New England in Canton. inaugural Boston Irish Festival fiddle champion Eileen Ivers, ing spirit Larry Kirwan, their and energy of the Connemara The traditional fiddle-accordi- Feis, a partnership with Liam whose resume includes appear- songs explore the social and region.
    [Show full text]
  • Diver Detection Sonar System
    Diver Detection Sonar System Product Code: 5510-01 Key Features Track & classify Single or multi-head networked systems Low false alarm rate Integration 3rd party security systems Fixed, temporary or expeditionary deployment Easy to use Overview The Diver Detection Sonar System is a single or multi-head active sonar Features system designed to automatically detect and track underwater and surface threats, principally divers, scuba or closed circuit, with or Identifies & classifies targets without propulsion aids, surface swimmers and unmanned underwater vehicles. Single or multi-head systems It will identify targets at ranges of up to 1,200 metres, depending on environmental conditions and product variant. 900 metres range for divers. Low power consumption 70 watts per sonar head It is small and lightweight so is quick to deploy from a boat, install in a port or fix along a coastline - providing you with an instant underwater security shield. Low false alarm rate Easy to use, security personnel do not need to be sonar experts to use it Maximum depth rating 50 metres once it is set up, it can be left to run autonomously. Can be Integrated with other It can be configured to meet the needs of commercial and infrastructure security systems facility protection projects as a standalone security sensor or integrated with third party C2 (Command and Control) security systems. It can be networked sonar, allowing entire waterfronts can be protected using a single operator station [email protected] | www.wg-plc.com | +44 1295 756300 1 Westminster Group Plc, Westminster House, Blacklocks Hill, Banbury, Oxfordshire, OX17 2BS, United Kingdom Diver Detection Sonar System Applications The practicality of the Diver Detection Sonar makes the system a realistic option for protecting a wide range of maritime assets: - Expeditionary - Warfare units in overseas ports are widely recognised as the most visible and vulnerable of targets.
    [Show full text]
  • STIDD-DPD-System-2
    DPD2 • OM2 • RNAV2 • CP2 • AP2 NEW! DPD System 2 Optionally-Manned Vehicles with Navigation & Control for EOD & Maritime SOF CATALOG 20 stiddmil.com MADE IN U.S.A. Manned or Autonomous... The “All-In-One” Vehicle Moving easily between manned and autonomous roles, STIDD’s new generation of propulsion vehicles provide operators innovative options for an increasingly complex underwater environment. Over the past 20 years, STIDD built its Submersible line and flagship product, the Diver Propulsion Device (DPD), around the basic idea that divers would prefer riding a vehicle instead of swimming. Today, STIDD focuses on another simple, but transformative goal: design, develop, and integrate the most advanced Precision Navigation, Control and Automation Technology available into the DPD to make that ride easier, more effective, and when desired . RIDERLESS! DPD2 - Manned Mode 1 DPD2 - OM2 Mode Precision Navigation, Control & Automation System for the DPD POWERED BY RNAV2 GREENSEA Building on the legacy of its Diver Propulsion Device (DPD), the most widely used combat vehicle of its kind, STIDD designed and developed a system of DPD Navigation, Control and Automation features which enable a seamless transition between Manned and fully Autonomous modes. RNAV2 was developed by STIDD partnering with Greensea as the backbone of this capability. RANV2 is powered by Greensea’s patent-pending OPENSEA™ operating platform, which not only enables RNAV2’s open architecture, but also seamlessly integrates STIDD’s OM2/AP2 Autopilot/S2 Sonar products into an intuitive, easy to use, autonomous system. When fully configured with the Precision Navigation, Control & Automation System including RNAV2/OM2/AP2/S2, any DPD easily transitions between Manned, Semi-Autonomous, and Full- DPD with RNAV2 Installed Autonomous modes.
    [Show full text]
  • Sonar Simulation (Adapted from the Steamship Portland 2003 Expedition)
    Bonaire 2008: Exploring Coral Reef Sustainability with New Technologies Expedition Sonar Simulation (adapted from the Steamship Portland 2003 Expedition) FOCUS Copies of “Sonar Simulation Activity,” one copy Side scan sonar for each student group GRADE LEVEL AUDIO/VISUAL MATERIALS 7-8 (Earth Science/Physical Science) Chalkboard, marker board, or overhead projec- tor with transparencies for group discussions FOCUS QUESTION How can side-scan sonar be used to locate TEACHING TIME objects underwater? One 45-minute class period LEARNING OBJECTIVES SEATING ARRANGEMENT Students will be able to describe side-scan sonar. Groups of 2-4 students Students will be able to compare and contrast MAXIMUM NUMBER OF STUDENTS side-scan sonar with other methods used to search 32 for underwater objects. KEY WORDS Students will be able to make inferences about Coral reef the topography of an unknown and invisible land- Bonaire scape based on systematic discontinuous mea- Sonar surements of surface relief. Side-scan sonar Topography MATERIALS Shoeboxes, one for each student group BACKGROUND INFORMATION Plaster of Paris, 1 – 2 lb for each student group Coral reefs provide habitats for some of the most Woodworking awl or sharp nail, 3 – 4 mm diverse biological communities on Earth. Most diameter people have seen photographs and video images Masking tape of shallow-water coral reefs, and many have vis- Pingpong balls, 2 for each student group ited these reefs in person. Historically, scientists Wooden dowel, approximately 3 mm diameter, have believed that reef-building corals were con- 30 cm long, one for each student group fined to relatively shallow depths because many Colored pencils, five colors for each student of these corals have microscopic algae called group zooxanthellae (pronounced “zoh-zan-THEL-ee”) liv- Ruler, one for each student group ing inside their soft tissues.
    [Show full text]