Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deep Sea Technology Is Put To The Test In Campus Tank

22.11.2002


Photo A: Louis Whitcomb supervises underwater robotics research at Johns Hopkins, including a new lab that features a tank filled with nearly 43,000 gallons of water.
Photo by Jay Van Rensselaer


Photo B: Doctoral student James Kinsey prepares to test the navigation and control systems that guide the lab’s underwater robot.
Photo by Jay Van Rensselaer


Tethered Robotic Sub Helps Engineers Refine Computerized Navigation, Control Systems

In a new indoor tank filled with almost 43,000 gallons of water, Johns Hopkins engineers are developing and testing computer control systems to serve as the "brains" for some of the world’s leading deep sea robotic exploration vehicles. To promote advances in underwater robotics, the Whiting School of Engineering recently constructed the circular hydrodynamics tank, 14 feet deep and 25 feet in diameter, inside a large lab space within Maryland Hall.

In the tank, researchers are testing the JHU Remotely Operated Vehicle, a small underwater robot developed at the university. Its navigation and control systems, also developed at Johns Hopkins, have recently been adapted and enhanced for use in the much larger Jason II vehicle, a new deep-sea oceanographic research robot operated by the Woods Hole Oceanographic Institution. The Johns Hopkins navigation program also has been deployed aboard the Deep Submergence Vehicle Alvin, Woods Hole’s inhabited oceanographic submersible.



Future navigation and control techniques devised in the new test tank are expected to improve the operations of deep-sea robots such as Jason II and Isis, a similar vessel that Woods Hole is developing for the University of Southampton in the United Kingdom.

"Our research goal is to develop new technology to enable new oceanographic research," says Louis Whitcomb, associate professor in the Department of Mechanical Engineering, who is director of the new testing facility. "Moreover, we collaborate with other institutions like the National Deep Submergence Facility at Woods Hole Oceanographic Institution to deploy these new technologies for ocean science on vehicles such as Jason II and Alvin."

Deep sea robots like Jason II are relatively new but increasingly important tools for scientists who want to explore some of Earth’s most remote and hostile frontiers. Human scuba divers can descend safely only about 300 feet, or 100 meters. Yet the deepest parts of the ocean lie 11,000 meters below the surface. To explore greater depths, scientists in the 1960s began building small inhabited submersibles. Such vessels have been used to explore the R.M.S. Titanic’s wreckage. But because such vehicles must carry their own fuel and air supplies, explorers are limited to eight to 12 hours per dive.

To overcome these limitations, engineers in the last 15 years have begun building uninhabited robotic vehicles that remain tethered to a research ship on the surface. Long cables feed power and instructions to the submersible and retrieve images and other data. These vehicles usually are equipped with video cameras to allow researchers to see what the vehicle "sees" in real time. They often possess robotic arms to collect artifacts, rocks and biological samples.

"The deep ocean is a cold, dark, high-pressure, inhospitable environment, and this equipment must be able to operate reliably under these conditions," Whitcomb says. "Inhabited deep submersibles, such as the U.S. Deep Submergence Vehicle Alvin, remain the only way for humans to directly observe the benthic floor with their own eyes. Deep-diving submarines are ideal for many tasks, yet they have limited endurance. One advantage of an uninhabited submersible is that it can explore the deepest parts of the ocean 24 hours a day, seven days a week, under the remote control of science teams that are working around the clock aboard the mother ship."

Operating a robotic vehicle from a great distance poses certain challenges, however, and that’s where Whitcomb’s team comes in. "Our lab focuses on two key problems that occur in the design of remotely operated undersea vehicles: navigation and control," Whitcomb says. "One of the most difficult things about maneuvering an underwater vehicle is that you need to know where it is. What, precisely, is its position and orientation on our planet? To determine these things, we’ve developed a computer system that integrates signals from a dozen on-board sensors to compute the submersible’s position and velocity."

Based on this information, an operator on the surface can use a joystick to move the undersea robot in three dimensions. The control system developed by Whitcomb and his students also allows an operator to tell a computer precisely where the vehicle should be located; the software then automatically moves the vehicle to that point. At the new Johns Hopkins hydrodynamics lab, researchers are fine tuning this system by sending commands over a tether line to six electric thrusters mounted upon the test submersible.

At sea, researchers on the surface can use this same system to carefully control a larger underwater robot’s movements, instructing the vehicle to move in a precise grid pattern. This allows the sub to collect the images and sonar data needed to produce photographic and topographic maps of sections of the ocean’s floor that contain interesting geological, biological or archaeological features. Whitcomb says his computer system also can direct a submersible to hover just 6 to 12 inches above the ocean floor, close enough to collect samples without disturbing ecologically sensitive surfaces. "With this system," he says, "we can control a vehicle’s position to within a few centimeters and its heading to within a degree."

Whitcomb supervises underwater robotics research at Johns Hopkins as director of the Dynamical Systems and Control Laboratory. The JHU Remotely Operated Vehicle was designed and built by one of his doctoral students, David Smallwood. Another of Whitcomb’s doctoral students, James Kinsey, is refining the underwater navigation system at the new testing tank. Other Johns Hopkins marine and oceanographic researchers will have access to the new tank. Funds for construction of the tank and related research were provided by the National Science Foundation.

Office of News and Information
Johns Hopkins University
3003 N. Charles Street, Suite 100
Baltimore, Maryland 21218-3843
Phone: (410) 516-7160 | Fax (410) 516-5251

Phil Sneiderman | EurekAlert!
Further information:
http://www.jhu.edu/news_info/news/audio-video/underwater.html
http://robotics.me.jhu.edu/dscl/
http://www.me.jhu.edu/

More articles from Process Engineering:

nachricht New technology for ultra-smooth polymer films
28.06.2018 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht Diamond watch components
18.06.2018 | Schweizerischer Nationalfonds SNF

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

NSF-supported researchers to present new results on hurricanes and other extreme events

19.07.2018 | Earth Sciences

Scientists uncover the role of a protein in production & survival of myelin-forming cells

19.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>