Ultrasound System Developed for Submarine Data, Power

Tristan Lawry (RPI)

An engineering doctoral student at Rensselaer Polytechnic Institute in Troy, New York has developed a new system using ultrasound to transmit large quantities of data and power wirelessly through thick metal walls, like the hulls of ships and submarines. The system built and demonstrated by Tristan Lawry (pictured right) is one of three finalists for the 2011 Lemelson-MIT Rensselaer Student Prize, awarded tomorrow.

Aboard naval surface ships and submarines, using wireless rather than wired connections not only improves efficiency and saves money, but also improves safety. To install safety sensors today on their exteriors, the U.S. Navy is forced to drill holes in the hull through which cables for data and power transmission are run. Each hole increases the risk of potential damage, including leaks and structural failure. Installing these sensors with wires also requires taking the ship or submarine out of commission, which can take months and cost millions of dollars.

Lawry’s invention, for which a patent has been applied, solves this problem. Unlike conventional electromagnetic wireless systems, which are ineffective at transmitting power and data through vessel hulls because of the shielding effects of the hulls, Lawry’s system uses ultrasound — high-frequency acoustic waves — that propagate signals through thick metals and other solids. The system converts electrical signals into acoustic signals and vice versa, allowing the system to form wireless electrical bridges across these barriers. The design separates the ultrasonic channels for data and power transmission to prevent interference.

The new system has demonstrated simultaneous and continuous delivery of 50 watts of power and 12.4 megabytes per second of data through a 2.5-inch-thick solid steel block in real time. The university says these results surpass all known published systems capable of simultaneous data and power transmission through metal.

Lawry says his design, with minor modifications, will have the capacity to support much higher power levels and data rates. His invention uses a communication technology that allows the transmission system to adapt to less-than-ideal conditions and mechanical variations over time. This flexibility is important for the system to meet real-world conditions outside of the lab.

The system can also communicate through thick metal walls without the need for a battery or any supplemental power source. This means sensors on the outer hull of submarines can be made to work with systems on the other side of the wall for many years without the need for human intervention.

Read more: Institute Developing Autonomous Underwater Robots

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