In 2003, engineers were
able to upgrade the previous
prototype to a state where
it could bear 500 Micro
Newton of lift. From 2003,
the robot insects have been
continuously
developed
to reduce weight, solve
problems in power supply,
increase the wing flapping
frequency, improve the wing
control and achieve a smooth
realistic stable flight.
As a result, the lift from a
single wing was increased
from 500 Micro Newton to
1400 Micro Newton in 2007
These robot insects are too
and it had a single actuator
small to be controlled by a
thorax to control both
remote controller. Therefore,
wings. It had a wing flapping
the need for an autonomous
frequency of 270 Hertz.
control system arose. As a
solution, the signals which
These robots made their
have been captured from
developments step by step
the external environment
slowly and today the robot
by sensors are processed
insects mainly consist of the
and sent to the control unit
sensory system, locomotive
which consists of several
and
control
system,
microcontrollers. Then the
communication system and
signals generated by the
power system. Their sensory
control unit are transferred
system mainly consists of an
to the locomotive unit. It
optic flow sensor in the eyes.
controls the whole-body
These sensors detect visual
dynamics of the robot
motions in the environment
insect by controlling the
and decide their path of
wings, thorax and actuators
the flight like the real flies.
relevantly.
Additionally, accelerometer,
temperature sensors, wind
The method of the power
speed sensors and other
supply of the robot insect
sensors relevant to the
was a great challenge for the
specific task of the robot
engineers since the lithium
are added to increase the
rechargeable battery packs
performance.
on their body increased the
weight of the robot and the
ground power supply added
a wire and caused restrains
for the flight. Engineers tried
to find solutions for these
problems for a long time and
finally in 2018 engineers at
the University of Washington
found a solution. Their
solution was to project a laser
beam to a photovoltaic cell
which is on the body of the
robot. Then the laser beam is
converted into usable energy.
Since this energy was not
enough for the robot, it had
to be increased by seven
times. By using this method,
the connecting wire could
be removed and it made the
robot insects another huge
step closer to the real flies.
With all these developments
insect drones have achieved
most of the goals by now. But
still, they have not achieved
the state of the ideal flies
in nature. Around the next
GAUGE Magazine University of Peradeniya
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