Subsea Robot Aims to Thwart Smugglers

FRIDAY, OCTOBER 3, 2014


A small, submersible robot under development could provide a new line of defense against smugglers trying to sneak contraband in ship hulls.

Researchers at MIT have designed a football-shaped robot with one flat side that slides along underwater surfaces to perform ultrasound scans, the university announced.

The robot can inspect ships for false hulls and propeller shafts, areas that often hide contraband. The bot was originally designed to look for cracks in nuclear reactor water tanks.

Its unique propulsion mechanism leaves no visible wake, making it easy to camouflage the robots in something such as algae, MIT said.

Port Security

"It's very expensive for port security to use traditional robots for every small boat coming into the port," said Sampriti Bhattacharyya, a graduate student in mechanical engineering who designed the robot with her advisor, Ford Professor Harry Asada.

"If this is cheap enough—if I can get this out for $600, say—why not just have 20 of them doing collaborative inspection? And if it breaks, it's not a big deal. It's very easy to make," Bhattacharyya said. 

The robot was unveiled at the International Conference on Intelligent Robots and Systems, which took place in Chicago, IL, Sept. 14-18. The MIT research was funded by the National Science Foundation.

Designed to be Unstable

Bhattacharyya used a 3-D printer in Asada's lab to built the robot's main structural components. Half of the robot consists of a waterproof flattened panel that houses the electronics. The other half houses the propulsion system—six pumps that pump water through rubber tubes.

The watertight chamber houses the robot's control circuitry, battery, communications antenna and inertial measurement unit.

The oval shape was intentionally designed to be unstable, Bhattacharyya explained.

"It's very similar to fighter jets, which are made unstable so that you can maneuver them so easily," she said. "If I turn on the two jets [at one end], it won't go straight. It will just turn."

ship inspection robot

"I have a great deal of interest in seeing if this type of technology can have a substantive impact on a number of missions or roles which I might be charged with in the future," said Nathan Betcher, a special-tactics officer in the U.S. Air Force.

However, this can make it difficult to travel in a straight line while scanning a ship hull. To counter this, Bhattacharyya designed all of the tubes to exit at different angles that she calculated for the greatest control over the robot.

Air Force Interest

Nathan Betcher, a special-tactics officer in the U.S. Air Force, has been keeping a close eye on the project.

"I have a great deal of interest in seeing if this type of technology can have a substantive impact on a number of missions or roles which I might be charged with in the future," Betcher said.

"I am particularly interested to see if this type of technology could find use in domestic maritime operations ranging from the detection of smuggled nuclear, biological, or chemical agents to drug interdiction, discovery of stress fractures in submerged structures and hulls, or even faster processing and routing of maritime traffic," he said.

Future Modifications

Initially, the researchers were just focusing on getting the robot to navigate an underwater surface in a straight line, so the prototype was built without an ultrasound sensor.

underwater robot

Half of the robot consists of a waterproof flattened panel that houses the electronics. The other half houses the propulsion system, whose six pumps pump water through rubber tubes.

The prototype ran on rechargeable lithium batteries, which last about 40 minutes, giving it plenty of time to inspect a small boat while traveling half a meter to a meter per second, Bhattacharyya said.

The researchers plan to use wirelessly rechargeable batteries in their next prototype as well as modify the propulsion system to boost the charge time to 100 minutes.

The researchers noted that encrustations on some ship hulls would prevent continuous contact, and the ultrasound emitter only works when in direct contact with the object it's scanning or when its distance is a specific multiple of the wavelength sound. Future steps in their work will explore how to create the right depth for the robot to perform ultrasound scans without surface contact.

   

Tagged categories: Colleges and Universities; Marine; North America; Program/Project Management; Research; Robotics; Security; Shipyards; Technology

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