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 Magnetic Quantum Objects in a "Nano Egg-Box"
25.07.2017 | Universität Wien

nachricht 3-D scanning with water
24.07.2017 | Association for Computing Machinery

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

Programming cells with computer-like logic

27.07.2017 | Life Sciences

Identified the component that allows a lethal bacteria to spread resistance to antibiotics

27.07.2017 | Life Sciences

Malaria Already Endemic in the Mediterranean by the Roman Period

27.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>