Underwater WPT Group

Underwater drones are expected to play an active role in freshwater and seawater applications ranging from bridge and dam deterioration diagnosis to environmental monitoring in aquaculture and marine resource exploration. To achieve these targets, research has been conducted on a system in which an underwater station is installed, and the drone charges and transmits data once it touches the bottom of the water.

We have proposed a coupler consisting of a power transmitter and receiver that can be configured with four flat electrodes to develop a simple and lightweight underwater wireless power and information transmission system. In freshwater, our system uses electric lines of force as carriers, i.e., electric fields, to transmit and receive power and information. In seawater, ions are the carriers, and the displacement current allows power and information to be transmitted and received.

The drone can be resident underwater by our system. The power to charge the drone is provided by offshore power generation (wind, tidal, solar, etc.) and is wired to the station. Information retrieved from the drone can be wired from the station to a buoy with an antenna floating on the sea, allowing communication with land and enabling work to be performed without having to go to the site.

We have achieved RF-RF power transmission efficiencies of over 90% for both freshwater and seawater. Currently, we are studying the efficiency improvement of the entire system and high-power RF power circuits.

Main Achievements

Main Press Releases (in Japanese)