Underwater robotic vehicle
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A novel robotic vehicle that includes a floating buoy and an underwater glider is being tested by the Russian military. The watercraft is a sensor and communication platform, which the Navy may find handy for submarine patrol missions.

Dubbed Fugu, the vehicle is an unusual combination. It has a floating part that looks like a surfboard, and an underwater part which serves as an engine for both of them.

The underwater part is a glider. It is a vehicle that changes its buoyancy to go up and down and uses fins to translate this seesaw-like motion into propulsion.

Underwater gliders have extremely high endurance because they require only a fraction of the energy that a more traditional AUV equipped with an electric motor does. The downside is that it is very slow.

Fugu is intended to be used as both a sensor platform and a communication relay, which would allow a submerged submarine to communicate via satellite link without surfacing and exposing it to the enemy, Mikhail Ryabtsov, head of the drone developer MAKO, told Izvestia newspaper.

"This is an autonomous robot with virtually indefinite endurance," he said.

The batteries of the glider part of Fugu are recharged by solar panels mounted on the buoy part. The buoy carries satellite communication equipment and sensors to monitor weather and other environmental data. The glider provides propulsion, monitors the ocean with several sonars, and has an acoustic modem which exchanges signals with submarines.

The unmanned vehicle is currently undergoing trials at the Defense Ministry's robotic research test center, the newspaper said.