introduction to quadcopter

1. Autonomous Attitude control research for Quad-rotor
Unmanned Aerial vehicle (UAV)
SUPERVISOR
Dr. Mohd. Amrallah B. Mustafa
BY
MOHAMMED Rameez Hadi
MSc. Candidat
Department Of Electrical and electronic engineering DIDATE
University Putra Malaysia

2. INTRODUCTION
• A quad copter, is an aerial vehicle which is
operated to fly independently , its also called a
Quad rotor helicopter, is a Multicopter that is lifted
and propelled by four rotors. .
• Each rotor produces both a thrust and torque about
its center of rotation, as well as a drag force opposite
to the vehicle's direction of flight
• The Control of vehicle motion is achieved by altering
the rotation rate of one or more rotor discs, thereby
changing its torque load and thrust/lift
characteristics.

3. BriefHistory
Breguet Brothers were the first people who built the quadrocopter in 1907.
they named their quadrocopter as Gyroplane. Their Gyroplane comprised of
four long girders fixed in the form of a horizontal cross. The flights of the
Gyroplane are considered to be the first human piloted flight of a helicopter,
but not a free or untethered flight. The Gyroplane never flew properly because
it lacked in stability and proper means of control.
The second attempt was made in 1922 when Georges de Bothezat built one
of the largest helicopters of the time which was also a quadrocopter. He named
his quadrocopter as Flying Octopus. His Flying Octopus flew successfully many
times, at low altitudes with slow moving speeds. However, the project was
cancelled because of low performance, high financial costs, and the increasing
military interest in autogiros at that time.

4. • In recent years, small quad rotor helicopters have
received widespread attention from researchers in both
civilian and military applications due to their low costs
and vertical take-off and landing (VTOL) characteristics
and advantages. These characteristics help quad rotors
to successfully achieve their search, rescue, prevention
missions in some disastrous circumstances (earthquake,
tsunami, fire, etc.), pesticide spraying, measurement of
coastline, forest and ice coverage rate across the whole
country, inspection of power lines and pipelines, picking
up or dropping off payloads .

5. Working principles
• Quadcopter is a device with a intense mixture of Electronics, Mechanical
and mainly on the principle of Aviation.
• The Quadcopter has 4 identical fixed pitched propellers and motors two
clockwise (CW) and two counter-clockwise (CCW), whose speed of
rotation and the direction of rotation changes according to the users
desire to move the device in a particular direction (i.e. Takeoff motion,
Landing motion, Forward motion, Backward motion, Left motion, Right
motion. )
• These use independent variation
of the speed of each rotor to achieve
control. By changing the speed of
each rotor it is possible to specifically
generate a desired total thrust.

6. In the most common design for quadcopter, the two sets of rotors (1,3)
and (2, 4) rotate in opposite directions as shown in fig below By changing
the rotor speeds, lift forces can be changed and motion can be created in
desired direction. Changing the speeds of all four rotors generate vertical
motion Increasing or decreasing the speeds of rotor 2 and 4 conversely
produces roll rotation coupled with lateral motion. Pitch rotation and the
corresponding lateral motion result from changing the speed of rotors 1 and
3. Yaw rotation results from the difference in the counter-torque between the
pairs of rotors

7. BASIC COMPONENTS OF QUADCOPTER
• BRUSHLESS DC MOTORS.
• ELECTRONIC SPEED CONTROLLER
• GPS,TRANSMITTER AND RECEIVER.
• FRAME, CONNECTING WIRES.
• BULLET CONNECTORS
• ACCELEROMETER.
• PROPELLERS.
• GYROSCOPE.
• A strong base as to hold the structure
• BATTERY.etc.,

8. BLOCK DIAGRAM

9. Quadcopter control design Features
• The quadrotor does not have complex mechanical control linkages due
to the fact that it relies on fixed pitch rotors and uses the variation in
motor speed for vehicle control
• these advantages come at a price as controlling a quadrotor is not easy
because of the coupled dynamics and its commonly under-actuated
design configuration
• the dynamics of the quadrotor are highly non-linear and several
uncertainties are encountered during its missions
• thereby making its flight control a challenging venture

10. Quadcopter Attitude
• The attitude controller is of great importance since it ensures the vehicle
to keep balance and perform the desired maneuver.
• The control objective of the attitude controller is to asymptotically track
the different demanded signals, even if there exist unknown
disturbances.
• The control system design of the quadcopter can be categorize into 5
types
• 1. automatic landing system : automatic landing system requires landing
the quadcopter safely. Safe landing is much more critical because
of the uncontrolled in decreasing the motor speed will significantly
affect the body of quadcopter to drop drastically and leads to unsafe
landing.

11. 2. The automatic take-off systems : used to initiate the UAV to fly from
the ground autonomously. The system should ensure the height of
quadcopter in a consistent condition. In this case, each of four motor
propeller must produce a force against the gravitational force to enable
them to lift the quadcopter. The good performance of the automatic
vertical takeoff system indicates how fast the quadcopter achieves its
desired altitude in steady state.
3. automatic navigation system
4. Hovering control system : The performance of the system also signifies
how smooth it maintains the height of quadcopter.
5. attitude control system : The control system is designed to produce the
desired acceleration of the attitude control autonomously.

12. Control Algorithm of a quadcopter
• Due to the nature of the dynamics of the quadrotor, several control algorithms
have been applied to it. As to be expected, each control scheme has its
advantages and disadvantages. Here we will review a ( PID ) control algorithm
to control the attitude of the quadcopter .
• Proportional Integral Derivative (PID)
The PID controller has been applied to a broad range of controller applications,
It is indeed the most applied controller in industry.
. 1. Turkoglu(Ankyda Ji1 and Kamran 2013) presented a microcontroller
controlled autonomous quadcopter. The microcontroller used is within an
Arduino kit. The research starts with developing a model for the quadcopter
using the nonlinear equations of motion. This step is followed by designing and
implementing a quadcopter with a camera for search missions. The controller
used to control the copter is the PID controller. The results they obtained
indicated the capability of the system they designed to achieve a stable flight of
the quadcopter.

13. 2 . In another work by Li and Li , a PID controller was applied to regulate both
position and orientation of a quadrotor. The PID parameter gains were chosen
intuitively. The performance of the PID controller indicated relatively good
attitude stabilization. The response time was good, with almost zero steady
state error and with a slight overshoot
3. Also in another work Lee, K.U., Kim, H.S., Park, J.-B. and Choi, Y.-H.used A PID
controller the attitude control of a quadrotor while a dynamic surface control
(DSC) was used for the altitude control. Applying Lyapunov stability criteria,
were able to prove that all signals of the quadrotor were uniformly ultimately
bounded. This meant that the quadrotor was stable for hovering conditions.
From the simulation and experimental plots however, it reveals the PID
controller to have performed better in the pitch angle tracking, whereas
large steady state errors could be observed in the roll angle tracking.

14. References
• Li, J. and Li, Y. (2011) Dynamic Analysis and PID Control for a
Quadrotor. International Conference on Mechatronics and Automation
(ICMA), 7-10 August 2011, 573-578.
• Lee, K.U., Kim, H.S., Park, J.-B. and Choi, Y.-H. (2012) Hovering Control
of a Quadroto. 12th International Conference on Control, Automation
and Systems (ICCAS), 17-21 October 2012, 162-167.