Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

School of Robofish Provides Basis for Teams of Underwater Robots

09.06.2008
Most ocean robots have to talk to scientists or satellites to share information. A school of robotic fish developed at the University of Washington communicate directly, allowing them to work cooperatively without ever coming to the surface.

In the world of underwater robots, this is a team of pioneers. While most ocean robots require periodic communication with scientist or satellite intermediaries to share information, these can work cooperatively communicating only with each other.

Over the past five years Kristi Morgansen, a University of Washington assistant professor of aeronautics and astronautics, has built three Robofish that communicate with one another underwater. Recently at the International Federation of Automatic Control's Workshop on Navigation, Guidance and Control of Underwater Vehicles she presented results showing that the robots had successfully completed their first major test.

The robots were programmed to either all swim in one direction or all swim in different directions, basic tasks that can provide the building blocks for coordinated group movement. This success in indoor test tanks, she said, will eventually provide the basis for ocean-going systems to better explore remote ocean environments.

"Underwater robots don't need oxygen. The only reason they come up to the surface right now is for communication," Morgansen said. Her robots do not need to come to the surface until their task is complete.

In the future, ocean-going robots could cooperatively track moving targets underwater, such as groups of whales or spreading plumes of pollution, or explore caves, underneath ice-covered waters, or in dangerous environments where surfacing might not be possible. Schools of robots would be able to work together to do things that one could not do alone, such as tracking large herds of animals or mapping expanses of pollution that can grow and change shape.

Co-authors on the recent study were UW doctoral students Daniel Klein and Benjamin Triplett in aeronautics and astronautics, and UW graduate student Patrick Bettale in electrical engineering. The research was supported by grants from the National Science Foundation and the Air Force Office of Scientific Research.

The Robofish, which are roughly the size of a 10-pound salmon, look a bit like fish because they use fins rather than propellers. The fins make them potentially more maneuverable and are thought to create lower drag than propeller-driven vehicles.

But while other research groups are building fishlike robots, what's novel with this system is that the robotic fish can communicate wirelessly underwater. Again, Morgansen looked to natural systems for inspiration. The engineers worked with collaborator Julia Parrish, an associate professor in the UW's School of Aquatic and Fishery Sciences, to record patterns of fish schools' behavior.

"In schooling and herding animals, you can get much more efficient maneuvers and smoother behaviors than what we can do in engineering right now," Morgansen explained. "The idea of these experiments (with schools of live fish) is to ask, 'How are they doing it?' and see if we can come up with some ideas."

The team trained some live fish to respond to a stimulus by swimming to the feeding area. The scientists discovered that even when less than a third of the fish were trained, the whole school swam to the feeding area on cue.

"The fish that have a strong idea tend to dominate over those that don't," Morgansen said. "That has implications for what will happen in a group of vehicles. Can one vehicle make the rest of the group do something just based on its behavior?"

Beyond finding the optimal way to coordinate movement of the robots, the researchers faced major challenges in having robots transmit information through dense water.

"When you're underwater you run into problems with not being able to send a lot of data," Morgansen said. State of the art is 80 bytes, or about 32 numbers, per second, she said.

The energy required to send the information over long distances is prohibitive because the robots have limited battery power. What's more, signals can become garbled when they reflect off the surface or off of any obstacles.

Messages were sent between the robots using low-frequency sonar pulses, or pressure waves. The new results showed that only about half the information was received successfully, yet because of the way the Robofish were programmed they were still able to accomplish their tasks. Robots that can independently carry out two simple sets of instructions—swimming in the same direction or swimming in different directions—will allow them to carry out more complicated missions.

Now researchers are using the fish's coordination ability to do a task more similar to what they would face in the ocean. The Robofish pack's first assignment, beginning this summer, will be to trail a remote-controlled toy shark.

For more information, contact Morgansen at (206) 616-5950 or morgansen@aa.washington.edu.

Images are posted with this release at http://uwnews.org/article.asp?articleID=42371. More information on the research is at http://vger.aa.washington.edu/research.html.

Morgansen | newswise
Further information:
http://vger.aa.washington.edu/research.html
http://uwnews.org/article.asp?articleID=42371

More articles from Information Technology:

nachricht NASA CubeSat to test miniaturized weather satellite technology
10.11.2017 | NASA/Goddard Space Flight Center

nachricht New approach uses light instead of robots to assemble electronic components
08.11.2017 | The Optical Society

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>