The slides provide the information about the basic terminologies used in the functioning of drone( specifically Quad-copter here), various sensors used and the drone's working.

1. BY –
MEDHA GUPTA
DEVENDER SINGH BOHRA

2. The mechanical force
applied by any fluid to
oppose the motion of
any object is called
Drag.
DRAG

3. Since here we are talking about Drones
passing through the air, so here we’ll be
dealing with the ‘aerodynamic drag’.
The difference in velocity between the
multirotor and the air is responsible for the
aerodynamic drag.
This comes to act only when the quadcopter /
multirotor is in motion otherwise there is no
drag.
For the movement of a drone, this drag force
along with the weight of the drone is required
to be overcome.

4. It is the force generated by the
propellers of the multirotor to
work against the aerodynamic
drag. The thrust is not the only
force responsible for lifting the
multirotor up, instead, it is the
force that helps to overcome the
drag resistance.
THRUST

5. It is the force which is
responsible for lifting the
drone up in the air acting
against the weight of drone.
LIFT

6. The propellers on the multirotor
generate a ‘lift’ force using principles
like Newton’s third law of motion and
the Bernoulli’s Principle(pushing the air
downwards and the difference in air
pressure).
For a successful flight, lift force must be
greater than the weight of the drone.

7. To fly in the forward or the
backward direction we need to
control the speed of rear motors
relative to the front motors and the
term used for this motion is Pitch.
PITCH

8. In order to pitch forward, the speed of rear
motors of the quadcopter must increase
relative to the speed of the front motors
which ‘pitches’ the nose (front) of the
quadcopter down and hence resulting in the
forward movement.
This can be achieved by either decreasing
the speed of the front motors or increasing
the speed of the rear motors.
In a similar manner to ‘pitch’ backward, the
speed of the front motors of the quadcopter
must increase relative to the speed of the
rear motors.

9. For the side to side
motion, the Speed of
the right motors is
controlled relative to
the speed of left
motors and the term
used for this type of
motion is ‘Roll’.
ROLL

10.  In order to ‘roll’ to the right, the speed of left
motors of the quadcopter must be increased
relative to the speed of the right motors.
 This ‘rolls down’ the quadcopter to the right side
in a sideways swaying movement.
 Similar to the Pitch, this can also be achieved by
either decreasing the speed of the right motors or
increasing the speed of the left motors.
 In the similar manner to ‘roll’ left, the speed of
the right motors of the quadcopter should be
increased relative to the speed of left motors.

11. The rotational movement
of the quadcopter is termed
as yaw.
YAW

12. It comes into action when the diametrically
opposing pairs of motors increase their speed
relative to the other pair.
In this case, the rotation speed of
diametrically opposing pairs of motors is
increased or decreased, varying the torque in
the direction of rotation of that pair which
causes the quadcopter to rotate in the
direction of the increased torque.

13. WORKINGOFMOTORSINUAV

14.  In a quadcopter, the four motors are placed at the edges of
the arms of the frame.
 The direction of rotation of each motor is such that the
torque generated by each of the motors cancels out.
 The adjacent motors rotate in the reverse direction while
the opposing motors rotate in the same direction.
 In order for the quadcopter to hover in place, it is
necessary to ensure that all the motors rotate at the same
RPM which must be sufficient enough to generate a ‘lift’
balancing its own weight and the torque due to all four
motors must be cancelled out so that the quadcopter don’t
yaw in a certain direction.
 In order to gain the altitude, all four motors of the
quadcopter must increase the speed of rotation
simultaneously and similarly to descend down, the speed
of all four motors must be decreased simultaneously.

15. FLIGHTCONTROLLER
The flight controller is
the Brain of the
Drone.

16.  This board is placed at the center and responsible
for controlling the firmware within the ESCs and
consequently controls the spin rate of the motors.
 The quadcopter cannot function accurately and
efficiently without the use of external sensors
added with the flight controller.
 So for a stable and precise flight different sensors
like Accelerometer, Gyroscope, Inertia
measurement unit (IMU) are used and interfaced
with the flight controllers and to make a
quadcopter fly better some additional sensors
like Barometer, Distance measuring sensors,
GPS, Magnetometer could be used.

17. In order to make the drone agile, the
acceleration and de-acceleration of the drone
must be quick, that means that it should pitch
forward in the beginning and when it is time
to stop, the quadcopter should pitch in the
opposite direction quickly in an aggressive
angle.
It is necessary so as to decrease the stopping
distance.
Secondly for the drone to be agile, the
quadcopter must be able to turn quickly with
a small turning radius.

18. IMPORTANTSENSORS
 Accelerometer
 Gyroscope
 Inertial measurement unit (imu)
 Barometer
 GPS
 Magnetometer
 Distance

19. FLIGHTCONTROLLER
The flight controller is
the Brain of the
Drone.

20. ACCELEROMETER
The accelerometer measures
the rate of change of the
object’s speed and tells
whether the object is going up
or down.

21. It senses both static gravity acceleration and
dynamic acceleration to detect the type of
motion.
The unit of measurement is meter per second
square or g (9.8 m/s^2).
It measures acceleration in three different
axes(x, y, and Z-axes).
The accelerometer senses both linear motion
and the direction of the ground by sensing the
earth’s gravitational pull.

22. GYROSCOPE
The gyroscope measures the rate of
rotation of an object about its axis
which is measured in degrees per
second or rotations per minute
(RPM). It is mounted on the center of
the quadcopter in such a way that it is
aligned with its axes and thus
providing information about the
orientation of the quadcopter. Three
axes of rotations are measured (roll,
pitch, and yaw).

23. INERTIALMEASUREMENTUNIT
(IMU)
For the accurate measurement of the
orientation, velocity and the location
of the quadcopter, IMU is used. It is a
board in which both accelerometer
and the gyrometer are combined to
get much stability. To correct the
errors in the gyroscope feedback,
IMU may also contain a
magnetometer.

24. BAROMETER
The barometer is a pressure
sensor that senses changes in
air pressure and hence can be
used to measure the altitude of
the quadcopter as with an
increase in the altitude the
pressure decreases.

25. GPS
It receives data from multiple
satellites in order to point the
geographical location of the
quadcopter. With the GPS system,
we can also set specific coordinates
for the quadcopter to fly to and
GPS also provides us an RTH
(return to home) function which
enables the drone to fly back to the
controller in case of connection
loss.

26. MAGNETOMETER
It acts like a compass to
measure the earth’s magnetic
field and serves the task of
correcting the drift of the gyro
and to serve as an ancillary to
the GPS system.

27. DISTANCESENSORS
Distance sensors are used for
the much accurate reading of
the altitude and to prevent the
drone from Collison with any
external obstacle. Generally,
these distance sensors use the
ultrasonic or light-based
system.