What is a quadcopter. explain how quadcopter work and its application and uses. why quadcopter become more important these days. comparisons between helicopter and quadcopter. explain the sensors...

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A BRIEF REPORT ON QUADCOPTER AND ITS WORKING
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Quadcopter:
Quadcopter is a helicopter with
four rotors. It is also known as quadrotor.
The four rotors of the quadcopter are
pointed upwards and they are a
anged in a
square pattern with equal separation from
the centre of mass of the quadcopter. The
angular velocities of the rotors which are
spun by electric motors control the
movement of quadcopter. Because of the
simple structure Quadcopter can be treated
as a symbolic design of small unmanned
aerial vehicles (UAV).
Quadcopters are compact rotor
craft air vehicles that can be applied to
indoor and outdoor inspection and
exploration tasks. Like a conventional
helicopter they can hover, however, they
have other significant advantages such as
mechanical simplicity, vertical take-off
and hover capabilities, and dynamic
manoeuvrability.
Figure 1 - A Quadcopte
Working of Quadcopter:
Quadcopters use fast on board
motor control to take care of stability. This
mechanical simplicity is also their main
attraction. Quadcopters can navigate in
three dimensions using only four moving
parts. And the high reliability of
ushless
motors makes them a simpler, more
eliable alternative to many traditional
flying platforms.
A quadcopter has four propellers
a
anged in a cross configuration or square
pattern. Two propellers rotate clockwise
and other two propellers rotate counter
clockwise, with which the quadcopter gets
lifted into the air without any net angular
momentum. Movement in the x and y
direction is attained by tilting the
quadcopter such that the thrust forms a
horizontal component. Figures below
present how the thrust of different
propellers can be modified allowing the
quadcopter to move. The platform of the
quadcopter is same as that of a helicopter
with respect to its mobility, however it is
simple to construct and can be operated
with ease because the blades of the
propeller are fixed-pitch.
The figures also show how a
quadcopter can control its pitch, row and
yaw angles. In the figure 2, the quadcopter
is level and still because of the equal thrust
provided by the motors (the red propellers
otate clockwise and the green propellers
otate counter clockwise). If one of the
pairs generates a difference in thrust, as
indicated in the figure 3, then the
quadcopter will roll or pitch about the
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other axis. In other case, if one pair of
motors rotates faster than the other pair, as
indicated in the figure 4, then the
quadcopter controls its yaw angle.
Figure 2 - Condition for level
Figure 3 - Condition for roll
Figure 4 - Condition for yaw
Pitch movement is obtained by
increasing (reducing) the speed of the rear
motor while reducing (increasing) the
speed of the front motor. The roll
movement is obtained similarly using the
lateral motors. The yaw movement is
obtained by increasing (decreasing) the
speed of the front and rear motors while
decreasing (increasing) the speed of the
lateral motors. This should be done while
keeping the total thrust constant.
Applications and Uses:
Because of their capability to
manoeuvre in dangerous locations while
allowing their human operators to be at a
safe distance the use of unmanned aerial
vehicles (UAVs) has grown in the military.
The larger UAVs are providing a reliable
long duration, cost effective, platform for
econnaissance as well as weapons. Hence
they have grown as an indispensable tool
for the military.
The Quadcopter is capable of being
distantly operated to fly for specific pre-
determined missions. Some missions may
e like examination of a difficult to reach
location, rapid deployment video from the
location of a fictitious campus incident, or
like surveillance video along a pre-planned
track around campus. Quadcopters are
used in search, rescue and surveillance
operations, construction inspections and
many more other applications.
Other applications include taking
pictures of buildings from the side for
advertisements, filming riots from the
safety of the air, scenes in indie movies,...