Wireless power
charger for electric wheel chairs
(January 20, 2016) In
a joint research project, Kyoto University's Center for Innovation (COI),
Panasonic Corporation, and Mitsubishi Heavy Industries, Ltd (MHI) have
successfully developed a battery-less sensor and wireless power charger for
electric wheel chairs.
Background
Wireless power charging technology enables power
transmission between distant places via electromagnetic field or
electromagnetic waves, thus giving rise to electric devices that require no
batteries. This has been hailed as "a game-changing technology" or
"a technology that will cause a paradigm shift", and has recently
drawn a great deal of attention from the academic and industrial societies
worldwide. Kyoto University's researchers have long been engaged in research on
wireless power charging technology that utilize microwave power transmission.
In an experiment that was publicly released in July 2015, Professor Shinohara
and his team used a drone to demonstrate wireless power transmission and sensor
technologies.
Battery-less
sensor
Research Method and
Achievements
A wide variety of research on wireless power charging
technologies is currently being conducted, and their standardization and
industrial application have increasingly been undertaken in Japan and the
world. Most of these research and development activities, however, focus on
technologies using the magnetic field, which only allows for wireless power
transmission between two points which are practically adjacent to each other.
On the other hand, in the current study, the team used microwaves and succeeded
in driving a device charged several meters away from the power source. With
this technology it's necessary to reduce interference, as the type of microwave
used in this technology is also used in mobile phones and other common devices.
High efficiency is also required for transmitting energy via radio wave. In
this project, Kyoto University and two corporations have jointly developed a
battery-less sensor for medical use and a wireless power charger for electric
wheel chairs. Panasonic has been working on the battery-less sensor
specifically for clinical use, and also developed a new, high-efficient power
reception antenna and beam technology for interference reduction. Reducing
interference and securing safety are crucial as the wireless power charging
system for wheel chairs require a much larger amount of power transmission than
a sensor driving system. Using a beam control system that minimizes emission,
MHI developed a safe and low-interference system and a microwave oscillator
with lower interference.