Quadcopter for Aerial Surveillance
Edmund Nhlanhla Moyo, Student No: 215078937,
Department of Electrical and Electronic Engineering Technology
University of Johannesburg, Johannesburg, South Africa
Abstract—In this document, we will discuss how an Unmanned
Aerial Vehicle (UAV) system is implemented and used to capture
aerial real-time data. A focus shall be given to the selection of the
most important component of the system, the flight controller,
and its sensors. The UAV system will be designed for stable flight
for accurate data capture. The project’s unique feature shall be
the inclusion of a sense and avoid system to allow for the drone to
avoid collisions with obstructions.
Keywords—Aerial Vehicle, Real-Time Data, Flight Controller,
Sense and Avoid.
I.
i.
INTRODUCTION
Background
remaining stationery in the air, as well as its VTOL
capabilities, are its main benefits [3]. Due to this, the
quadcopter can operate in almost any situation, including
inside or in confined locations with restricted agility.
Many of the characteristics of a quadcopter may also be found
in a traditional helicopter with one main rotor and one tail
rotor. The conventional helicopter needs a complicated hub to
make it feasible to spin the motor axis to produce a translating
action, but the quadcopter has no moving elements other than
the rotating motors and propellers. The quadcopter is also
more adaptable in terms of where to set the centre of gravity
and less susceptible to vibrations. Flying inside buildings is
safer since the rotors can be covered more readily and are
considerably smaller [3].
As was previously mentioned, the standard quadcopter design
contains only the propellers as moving elements. The only
method to create a lateral motion is to tilt the entire frame
because the motors and their propellers are fastened to it. The
quadcopter does not need a tail rotor to regulate yaw motion,
in contrast to a typical helicopter. The quadcopter features four
motors with a clockwise and counterclockwise rotation of two
each. There will be a moment near the yaw axis if the
clockwise and counterclockwise motor pairs spin at different
rates [3].
Unmanned aerial vehicle (UAV) development began at the
turn of the 19th century when the majority of the first
prototypes were intended to be airborne missiles or remotely
piloted weapons [1]. Unmanned aerial vehicles (UAVs) now
have a far larger range of uses and are no longer just used for
military objectives. Recent technology advancements have
opened new possibilities and increased the accessibility of
these flying machines for public usage. UAVs are now
ii.
Objectives
routinely flying today on regular basis, guarding the borders,
keeping an eye on agriculture, and recording or
The goal of this project was to design and implement a
photographing TV either provides information or augmented
quadcopter, often known as a four-rotor aircraft, that could fly
reality toys for kids. All these opportunities provide a broad
steadily while being controlled manually by radio. The
range of UAV enhancement options [1].
primary focus of the project is to design a system that can
The advancement of technology has also made it possible for
achieve impeccable flight stability using advanced control
enthusiasts and other amateurs to become ardent drone pilots.
systems techniques. The aim is also to use an Ardupilot PX4
Most civil applications, like search and rescue, or other
Cube Orange flight controller to control the flight of the
cutting-edge applications benefit from some form of computer
quadcopter and to configure the controller with my own
aided autonomous or automated flight, even though most
configuration and drone code. Another aspect of the project is
hobbyists and other enthusiasts buy drone systems for the
to also capture aerial data using the drone. The PX4 Cube
enjoyment of flying the craft around the yard, taking quality
Orange flight controller is a very versatile microcontroller
aerial videos, or competing in First Person View (FPV) racing.
board that can be used for professional flight [4]. Therefore,
The operator can put up a "flight plan" in a control centre
the user must configure and set it specifically for the
application to have a commercial UAV fly from one GPS
appropriate mission. This report's goal is to outline the
waypoint to another, then return home, or travel to a GPS
project's proposal as well as the measures that are to be taken
waypoint, snap a 360-degree photo, then travel back to its
to implement the project.
starting point [2].
The quadcopter is a common type of drone, mostly due of its
distinctive features. The quadcopter's hovering capability or
PJEELB3
ELECTRICAL PROJECT REPORT
2022
iii.
Problem Statement
Many of the present environmental issues facing the globe are
a result of industrialization. For instance, industrialization is
responsible for climate change, dangerous air pollution levels,
the depletion of fishing supplies, poisons in rivers and soils, an
abundance of garbage on land and in the seas, the loss of
biodiversity, and deforestation [5].
Innovations are advancing more quickly, more effectively, and
more broadly than ever before as the Fourth Industrial
Revolution (4IR) picks up speed. Additionally, technology is
getting more interconnected, and we are witnessing a fusion of
the digital, physical, and biological worlds. By influencing the
economies, values, identities, and prospects for the next
generations, new technologies are facilitating societal
transformations [5].
There is a need for advanced, reliable, and cost-effective
systems to collect aerial data and deliver packages. Drones can
also be used in precision agriculture where they are able to do
crop spraying and dusting thus increasing productivity in the
agricultural sector. After all, food security is one of the major
concerns as the Fourth Industrial Revolution looms.
It is apparent that there is a need for stable flight for accurate
real-time data capture, error-free data transmission in precision
agriculture, and crash-free landings in drone delivery. The
need for stable flight is especially important for the drone
pilot, who needs to be able to accurately fly their drone to the
exact location of the target, as inaccuracies might result in the
loss of the drone, injuries to people or animals, or worse still,
fatalities.
motor situated on the same diagonal rotates either clockwise
(CW) or counterclockwise (CCW) in the same direction
(CCW) [7]. When driving a car, we can move forward,
backward, to the left, or to the right, but when discussing a
flying system, we wouldn't use the same terminology. Yaw,
roll, and pitch are terms used in the flying system [7].
Before learning about a quadcopter's flight dynamics, it is
important to grasp its three primary angular motion
parameters: yaw, roll, and pitch.
Figure 1: Three axis of drone movement [11]
II.
LITERATURE REVIEW
i. Components for unmanned aerial vehicles
We need to attach several sophisticated electrical gadgets to
construct a dynamic unmanned aerial vehicle [6]. Many smart
electronic components, including a brushless DC motor, a
PX4 Cube Orange Multi-Rotor controller, an ESC (electronic
speed controller), and a 5500 mah Lithium Polymer battery,
have been employed in this application. All those electrical
components and their behavior will be covered in this section.
This part also includes an in-depth discussion of the flight
dynamics that the flight controller is responsible for. This
chapter also covers the design of the control systems of the
drone.
ii. Flight Control Mechanics
The relative thrust of each of the four motors is changed to
regulate the quadcopter's mobility. We are employing Xshaped quadcopters in this instance. In this quadcopter, the
III.
i.
THE QUADCOPTER
Actuators
Here, a brushless DC motor (BLDC) has been employed. A
brush placed across the shaft of a DC motor switches the coils'
power direction [5]. The coils and magnets of a DC motor are
utilized to drive the shaft. These brushes are absent from
brushless motors. The motor, which is mounted to the
mounting, has coils in the middle. They have many magnets
fixed to an exterior cylinder that is connected to the spinning
shaft. The coils are so secured. It indicates that a brush is not
necessary because the wires may reach them directly [8].
Compared to a DC motor, a brushless DC motor rotates at a
significantly greater speed and consumes less power (at the
same speed). Additionally, there is no power loss because of
brush transfer. We can see a 1000KV BLDC motor with three
input wires in the figure below. These three wires will be
connected to an electronic speed controller (ESC) [5].
Each brushless motor has a Propeller installed on top of it.
There are several sizes and forms of propellers. We are
employing propellers with dimensions of (15*5.5), which
means that their diameter is 15 and their pitch is 5.5 inches.
Pitch provides an effective area whereas diameter provides an
area. The propeller will produce more thrust and be able to lift
more weight if we use one with a greater pitch for a similar
diameter, but it will also need more electricity. More velocity
and agility are offered by a high RPM, but less weight can be
lifted [8].
ii.
HD Camera
A camera shall be used to view and capture real-time data
using the drone. The camera of choice is the Run Cam Nano 3.
vi.
Circuit Diagram
Below is the full circuit diagram of the Quadcopter:
Electronic Speed Controllers (ESC)
Since brushless motors are three-phase, they cannot be used
with DC power. To keep the motor spinning, ESC continually
provides three frequency impulses with distinct yet adjustable
phases. Both the battery input and the motor's three-phase
output are present.
Using pulse width modulation, the controllers connected and
disconnected the motor about 2000 times per second (PWM).
In place of a mechanical switch, a MOSFET transistor is
employed as a switch. Motors cannot notice the changeover
because it happens so quickly [7]. When a 24 V battery is
attached, the motor only operates at half speed since it only
recognizes the battery as 12 V half the time. The motor
inductance, which maintains the motor current flowing
continuously, is likewise impacted by the switching speed.
The battery current will be equal to 50% of the motor current
since the battery is only supplying that current 50% of the
time. The internal circuit diagram of the ESC and its current
(Amps) response over time are shown in the figure below.
iii.
v.
Figure 2: The layout of the Unmanned Aerial Vehicle [3].
An inclusion of Detect and Avoid system shall be included to
give the project an interesting twist. The drone shall be wired
and configured to detect and avoid possible obstructions.
Using the circuit diagram and components the actual quadcopter
is as depicted in the figure below.
Radio and Reciever
A transmitter serves as a user's controller. The user can only
control the quadcopter using this transmitter. The foundation
is radio communication. The drone has a receiver attached to
it, and the receiver has an antenna that it uses to communicate
with the transmitter. This entire conversation is wireless. A
signal is sent from the transmitter to the receiver, which then
delivers it to the flight controller. Here, we are utilizing a
transmitter and receiver from FLYSKY. This transmitter has a
range of 1500 meters, however, if it is used in an area with a
lot of magnetic interference, its range will be reduced.
iv.
Power Plant
Figure 3: The complete quadcopter as built.
Quadcopters frequently employ lithium polymer (LiPo)
batteries due to their lightweight design and high current
rating. Here, 3 Cell LiPo batteries were utilized. LiPo batteries
have a single-cell capacity of up to 3.6 V. The 2200mAh LiPo
battery has a voltage of 11. V (3 cells), a discharge rate of
30C, and a capacity [7]
vii.
Specifications of aircraft
The aircraft specifications are as follows:
• Max Flight time/Endurance = 30 minutes
• Max speed 300km/hr
• Max payload = Up to 1Kg
• Range = 1500m
•
•
•
Vertical take-off & landing capability
practically take off and land anywhere)
Hovering capability
Max altitude 100m
IV.
(can
METHODOLOGY AND TASKS
Like any other robust project, a comprehensive methodology
must be followed to ensure successful completion. This
includes a thorough planning phase. In fact, the planning
phase is the most important phase of the project. A lot of time
is spent figuring out which components exactly are to be used
and what their sizing should be. The next phase is the
execution phase. In this phase, the connection of components
is implemented. The flight controller is also configured to the
desired specifications.
The final phase is the testing phase. This is where the system
is checked and tested to ensure that it is working as intended.
The testing phase is also where the system is debugged and
tweaked. The actual flight is also performed in this phase. The
last phase is the analysis phase. This is where the data is
analyzed. This phase is also where the results are presented
and a comprehensive conclusion to the project is drawn.
Figure 4 below gives a summary of the process steps
V.
RESULTS AND OUTCOMES
The results of flight test conducted at the James and Ethel
Park, Johannesburg are shown in the figure below.
Figure 5: The flight path of the quadcopter during the successful test.
Figure 6:The graph depicting altitude vs time.
Figure 4: The block diagram of the formulated methodology.
Figure 7: The graph depicting voltage vs time
It was also important to understand the flight dynamics
surrounding vertical take-off and landing so that we are able to
include a sense and avoid system and how to configure it in
our flight controller and Ground Control Station. We also
wanted to determine the behavior of the Brushless DC motors
and their relative power consumption when used to hover. The
flight controller we used is the PX4 Cube, which is a
sophisticated autopilot system.
Astounding results were achieved from the Vertical Take Off
and Landing/Hover Test bench as the system is optimized for
sensing and avoiding obstacles and gathering data.
REFERENCES
Figure 8: The graph depicting current vs time.
VI.
PERFORMANCE AND DATA ANALYSIS
From the results above, in the tests, the maximum altitude
achieved is 45m and this is achieved after a climb of 2
minutes. Caution was being taken not to push the parameters
to their rated maximum. As expected, the battery voltage
experienced an exponential decrease. The full charge voltage
is found using the formula below:
Voltage = No of battery cells * 3.8
= 8 * 3.8
=30.4v
The flight commenced with a nominal voltage of 28v and
ended at a voltage of 25v. This was done so as not to reach the
critical voltage of the cells as this would have potentially
caused a crash.
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]
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]
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]
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A fairly constant current output was maintained throughout
the test. This is also important during hovering to maintain the
balance of the aircraft.
[8
]
CONCLUSION
The objectives of the project explore a lot of aspects in the
fields of electrical, electronic, and aeronautical engineering.
The first part of the project is to achieve stable flight using
advanced control systems. The second part of the project is to
use brushless DC motors to replace traditional DC motors for
propulsion. The third part of the project is to achieve remotecontrolled flight using a radio control transmitter and receiver.
The fourth part of the project is to develop a quadcopter drone
that is capable of aerial data collection using an HD camera.
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