The decrease and aging of Japanese fishermen is a serious problem, and in order to reduce the high-load work by human hands, which is one of the factors, automation such as aquaculture net cleaning robots is being promoted.In the future, it is expected to develop a so-called underwater drone, which is a robot that resides in the sea and is responsible for everything from water quality management to fish growth checks.
Drones need to be recharged and also need to collect data collected underwater.In addition, the weight increase must be suppressed.Therefore, this time, the research team of Toyohashi University of Technology has developed a new type of power transmitter / receiver that realizes wireless power supply and information communication in the sea via a power supply station in a lightweight and space-saving manner.
In the world of wireless power, seawater behaves as a very lossy dielectric.On the other hand, focusing on the fact that high-frequency current flows in seawater rich in ions, this team constructed a new operation theory from the equivalent circuit of a power transmitter / receiver that focused on the conductivity of seawater.Based on this theory, we designed a power transmitter / receiver using four ultra-thin flat plates, prototyped and measured it. As a result, even if 4 kW of power was transmitted in seawater at a distance of 1 cm, the power supply efficiency was 2. The result of% or more was obtained.Using this, we also succeeded in power supply experiments to small underwater drones and real-time video communication.The total weight of the power receiver and power circuit installed in the drone is about 90g, which is extremely lightweight.
It is expected that this result will dramatically improve the operational efficiency of underwater drones, and ultimately lead to the development of an underwater drone system that can manage everything on land.
Paper information:[IEEE Transaction on Microwave Theory and Techniques] Design of Conductive Coupler for Underwater Wireless Power and Data Transfer
[IEEE Transactions on Microwave Theory and Techniques] Design of a Capacitive Wireless Power Transfer System for Operation in Fresh Water
