Underwater Robot to Aid Port Security

Photo courtesy MIT

by Scott Kesselman



Researchers a MIT unveiled an oval-shaped maritime robot, smaller than a football, with a flat panel to perform ultrasound scans along an underwater surface to aid port security.



Initially created to look for cracks in nuclear reactor water tanks, the robot was revealed at the International Conference on Intelligent Robots and Systems and will be capable of detecting false hulls where smugglers can hide contraband.  



“It is very expensive for port security to use traditional robots for every small boat coming into the port, says Sampriti Bhattacharyya, a grad student in mechanical engineering, who designed the robot with her advisor, Harry Asada.  “If this is cheap enough – if I can get this our for $600, say – why not just have 20 of them doing a collaborative inspection?”



The main structure was built using a 3-D printer and is propelled between a half and one meter per second by six pumps that expel water through rubber tubes. The side of the robot with the propulsion system is permeable, while the flattened half, to be used for scanning, is waterproof and houses the electrical components, battery and sensors.



Currently, prototype testing involves navigation and propulsion refinements, as an algorithm is used to adjust the velocity of water expelled through each tube to refine movement.  This model does not include an ultrasound sensor and the lithium batteries used provide only about 40 minutes a charge. 



The next prototype will feature wirelessly rechargeable batteries and modifications the propulsion that should increase operation time on a single charge to 100 minutes.  This will be ample time for a team of robots to search a ship and shifts of bots can cycle throughout the day to allow time for each unit to recharge.



The biggest challenge will be contending with deposits on boat hulls that interfere with the flat surface needed to take ultrasound images. The team is exploring use a mechanical system to create hydrodynamic buffers that would allow scans without surface contact.