Page 13 - trends in automation

T he dragonfly has become highly
specialised over the course of its
300 million-year evolutionary
history, developing a unique way
of flying. It moves effortlessly in all direc-
tions, can hover in the air and glide without
beating its wings. Its ability to move its two
pairs of wings independently means it can
slow down and turn abruptly, accelerate
swiftly and even fly backwards. Realising
the highly complex flight characteristics
of the dragonfly certainly wasn’t an easy
task to take on. However, the developers
of the Bionic Learning Network, a network
Festo shares with well-known universities,
institutes and development companies,
have succeeded in doing just that, and to
perfection, too. The BionicOpter is the
first model ever that can master more
flight conditions than a helicopter, plane
and ­glider combined.
Lightweight construction
The artificial dragonfly is a true light-
weight. With a wingspan of 63 cm and a
body length of 44 cm, it weighs just 175 g.
This is thanks to the BionicOpter’s ex-
tremely lightweight construction. Its wings
con­sist of a carbon-fibre frame and a thin­
foil covering. The structure of the hous-
ing and the mechanical components made
from flexible polyamide and terpolymer
make the entire system flexible and ultra-
light, yet sturdy. The very small ribcage
houses the battery, eight servo motors, ­
a high-performance ARM microcontroller
as well as sensors and ­wireless modules.
Compact and integrated
The BionicOpter’s unique way of flying
is made possible by the lightweight con­
struction as well as the high level of
function integration. For the artificial
dragonfly, this means that components
such as sensors, drives and mechanical
components as well as communication,
open and closed-loop control systems
are installed in a very small space and
adapted to one another. Festo is thus
­illustrating the possibilities and per-
spectives of function integration in an
extremely compact format. The remote-
controlled dragonfly communicates
­wirelessly in real time and exchanges
­information continuously. It combines
dif­ferent sensor evaluations and identi-
fies complex events and critical states
automatically.
Intelligent kinematics
In order to stabilise the flying object, data
on the position and the twisting of the
wings is continuously recorded and eval-
uated in real time during the flight of the
dragonfly. The acceleration and the tilt-
ing angle of the BionicOpter in space can
be measured using the inertia sensors.
The integrated position and acceleration
sensors detect the speed and spatial di-
rection of the dragonfly’s flight. In addi-
tion to control of the flapping frequency
and twisting, each of the four wings also
features an amplitude controller. This
means that the direction of thrust and
the intensity of thrust for all four wings
can be adjusted individually, thus en­
abling the remote-controlled dragonfly to
move in almost any orientation in space.
The intelligent kinematics correct any
­vibrations during flight and ensure flight
stability both indoors and outdoors.
Fascinating flyer
The dragonfly is one of the most elegant and skilful aerial acrobats in the
­insect world. The ability to move its two pairs of wings independently enables
it to change direction abruptly, hover in the air or, like some of the over­5,600
differ­ent species, even fly backwards. Its wingspan measures ­between 20 ­
and 110 mm. Large dragonflies can reach speeds of up to 50 km/h without ­a
tailwind.
2.2013 trends in automation
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