2. UAV
Presented By:
• Alexander Mohamed
Osman
• Riyad Ahmed El-laithy
• Ruyyan Ahmed El-laithy
• Peter Raouf Zaki
3. Introduction
• What are UVs ?
• What are UAVs ?
• Types of UAVs
– Fixed wing UAV
– Helicopter UAV
– Quadroter UAV
4. Quadrotor Advantage Over Fixed-
Wing Vehicle
• Less design complexity.
• Minimal space for take-off and landing. A
VTOL vehicle.
5. Quadrotor Advantage Over
Helicopter
• Quadrotors do not require mechanical
linkages.
• The use of four rotors allows each
individual rotor to have a smaller diameter
than the equivalent helicopter rotor.
7. Control Scheme
Direction ∆ Motor 1 ∆ Motor 2 ∆ Motor 3 ∆ Motor 4
Z+ (Up) + + + +
Z- (Down) - - - -
X+ (Left) + 0 0 +
X- (Right) 0 + + 0
Y+ (Forward) + + 0 0
Y- (Backward) 0 0 + +
8. Materials used in building the
Prototypes
• Balsa wood planks
• Super glue
9. The First Prototype:
• Disadvantages
– It was too heavy to lift
• 197 grams.
– The spacing between
the motors
Picture of 1st Prototype
10. The Second Prototype
• What is improved in
that prototype ?
– The weight decreased
• 93 grams.
– The motors are closer
to each other
• The result Picture of 2nd Prototype
– Light lift
11. The Second Prototype
• Disadvantages
– Still heavy to hover
– Disturbance in the rotor
wind vortex
– Not aerodynamic
Picture of 2nd Prototype
13. The Third Prototype
• What is improved in this prototype ?
- Starting the X design
- Reduced air resistance.
- More lift gained .
- Lightweight .
• 45 Grams.
Picture of the 3rd Prototype
14. The Third Prototype
• Problems with the new design:
– Too fragile.
– The reduced air resistance was still not enough.
• What can be done ?
15. The Fourth and Final Prototype
Top: Isometric:
Front: Side:
16. The Fourth and Final Prototype
• Achievements:
- Rigid and Lightweight.
(43 Grams).
- Great lift.
- Highly reduced air
resistance.
Picture of Final Prototype
17. The Fourth and Final Prototype
• Specifications:
-Total Weight (with all components) = 990 Grams
(0.99 Kg)
- Acceleration at Full Power = 4.061m/s2
- Vertical Force at Full Power = 4.021N
(Assuming Differential Torque = 0)
- Lateral thrust beyond Hover Thrust = 0.4141g
- Power – to – Weight Ratio = 1.5 : 1
18. Controller Design
• Design Objectives
– Stability
– Obstacle Avoidance
– Determining Position
– Communication
19. Controller Design
• To achieve these objectives we need
– IMU (Inertial Measurement Unit)
– 5 Ultrasonic Sensors
– GPS Receiver
– RF Transceiver
20. Controller Design
• MicroController requirements
– 4 PWM Outputs
– 11 Analog to Digital Channels
– High speed crystal
• PIC18F4431
– 4 14-bit Power PWM modules
– 9 10-bit 200Ksps ADC channels
– 40 MHz Crystal Max
22. Controller Design
• Problems with PICxxFxxxx
– IMU and RF work at 3.3V Logic
– GPS messages are TTL 0 – 2.85V
– Ultrasonic readings range from 0 – 2.54
• PIC16LF777
– 3 10-bit PWM modules
– 14 10-bit ADC channels
– 10 MHz Crystal max
– Operating voltage range from 2V – 5.5V
– 2 Connected together
30. Controller Design
• Last Main Board
– Photo-couplers
– Interface boards
– Sub-boards
– 90° Interface connections
– Even smaller design
– ICSP (In Circuit Serial Programming) wires were
added onto the circuit later on
– LEDs for easier debugging without the need for
expensive hardware such as ICDs (In Circuit
Debuggers)
37. PCB Production Procedures
• What do you need to make a PCB
– Laser printer
– Glossy paper
– Acetone
– Clothing iron
– Acid
– Steel sponge
38. PCB Production
• Clean the surface of
the board
• Print the circuit
• Start folding
• Start ironing
• Put it in hot water
• Start chemical etching
• Finalize with drilling
39.
40. Analog-To-Digital Converter
• ADCs:
- Importance of Data Acquisition in our UAV.
- Vref set on 3 Volts.
- Ultrasonic sensors.
- Gyrometer.
- Accelerometer.
41. ADCs
• ADC Reading = (Vin/Vref) X (2N); where
Vin : is the Voltage input.
Vref : is the reference voltage.
N : is the resolution of the ADC Conversion.
42. Ultrasonic Sensors
• Ultrasonic Sensors:
- Maximum Range: 254 inches
(6.45m)
- Minimum Range: 6 inches (15cm)
(Blind Spot)
- New Readings every 49
Milliseconds.
- Has Serial/Analog/Pulse Width
Modulation output.
- Every 0.01V represents 1 inch.
43. Ultrasonic Sensors
• Calculating Distance inside ADC:
- Distance = (Vin/Vref) X (2N);
• For example:
50cm = 0.20 Volts shown on Ultrasonic
Sensor.
(0.20/3.30)*1024 = 62.061
To calculate backwards to know accuracy:
(62/1024)*3.3 = 0.1998 Volts on input pin.
Therefore, the Error = (1-(0.1998/0.20))*100
= 0.1%
44.
45. PWM
• Pulse Width Modulation:
- Processing after Data Acquisition for scenarios.
- Implementing the data acquired as output on
Motors.
- Frequency for Motor Output (750Hz).
46. PWM
• How It works?
Obtains Average of On/Off Intervals within period.
• VAV = 1.65 Volts since half the time is ON and the
other half is OFF.
47. Testing Sensors
• A great way to test the sensors is using an
LCD.
– Tangible.
• Used to test all sensor outputs after
processing:
- Ultrasonic.
- Accelerometer.
- Gyrometer.
- GPS Receiver.
- RF Transceiver units.
50. GPS Applications
• GPS has become a widely used aid to
navigation worldwide.
• A useful tool for
– Map making.
– Land surveying.
– Scientific uses.
51. NAVSTAR Constellation
• There is a constellation of 30 earth orbiting
satellites transmitting precise radio signals.
• Orbits are set up so that at any given point and time
on the earth’s surface there are at least six of these
satellites in reach.
52. GPS Messages
• Almanac contains orbital data
• Ephemeris contains the satellites precise
orbit.
59. Input Messages
• Input messages are used for initialization.
• Selected input messages were:
– Set Serial Port
– Query/Rate Control
– Development Data On/Off
• CRC required for input message.
61. Output Message
• Message of choice was RMC, it contained
all we needed which was:
– Latitude & Longitude
– Course Heading
– Velocity
62. USART
• The GPS communicates with the PIC
through USART.
• Communicates at 4800 bps
• Asynchronous
63. Validating Message
• When the message is validated:
– The latitude, longitude and heading are ready
to be extracted to the Main PIC.
– RF function is called to transmit data, to the
simulator.
64.
65. Inertial Measurement Unit
• Gyro
– Measures angular velocity on the x and y axes
– Can also be used to calculate displacement
angle
– Sensitivity of 2mV/°/sec
66. Inertial Measurement Unit
• Accelerometer
– Measures acceleration on the x,y and z axes
– Sensitivity of 300mV/g
– Can also measure angles
67. Inertial Measurement Unit
• IMU
– Gyrometer & Accelerometer
– Transform acceleration readings onto the 3
original axes.
– Velocity & Displacement can be calculated
from accelerometer readings on 3 main axes.
70. Microcontroller Communication
• SPI Communication
– Master/Slave Configuration
– 3 pin connection
– Synchronous Serial Transmission
– 8-bit at a time
– Control Messages, & Sensor Values
71.
72. Laipac RF
• Haw the transmitter
works ?
– Data input to the to
the encoder.
– transmitting the
data
76. Laipac RF
• Conclusion after testing
– Too slow.
– Big size .
– Very small payload.
– Very short range.
– Need an external antenna.
77. RF-24G transceiver
• Specification
– Very small size
– Long range
» 280 meter
– Built in antenna
– 29 byte payload
– Fast transmission &
reception
» Up to 1Mbps
– Shock burst mode
78. RF transceiver
• States of Shock burst
– Active mode
– Configurations mode
– Standby mode
– Power down mode
86. Problems
• Serial Port
• Signed Byte
• Graph Origin
• Converting Longitude and Latitude to
Pixels
87. Solutions
• Javax.comm
-CommPortIdentifier
-Streams
-SerialEvent
-Converting any data to String then to Bytes
• Convert to short add 256 if negative
• -( ( (Height - 90 ) / Range ) * Actual ) + Separation
• ((width /|(difference between top left longitude and bottom right
longitude)|)*|(acquired longitude-top left longitude)|)
99. Imaging circumstances
• Type of the acquistion
• The properties of the target object?
• The environment
• The objective
100. Challenges
• Colored image
• Variance in lighting
• Uninformed background
• The target is colored
• The target’s shape is not defined
101. Our program
• Acquisition phase
• Visualization phase
– Estimate the degree of the color
• Processing phase
– Applying Median filter
102. Analysis phase
• Make a binary image showing the blue
pixels
• If there is other blue objects it will be
shown as white objects
103. • Pixel connectivity
• The use of the labeling function
– [label,num]=bwlabel(y,4);
– stats=regionprops(label,'Area','BoundingBox','
PixelList');
• What are the importance of those
functions
104. • Finding the object with the largest area
• Locating its position
• Making a bounding box around
• Send the target position to the UAV
108. FUTURE IMPLEMENTATIONS
• Gyrometer & Accelerometer drift
correction
• Ultrasonic sensors attached to servos.
• High powered brushless motors.
• A long range high resolution camera.
• Magnetometer
• Chassis redesign
109. CONCLUSION
• Local market restrictions inhibited time.
• Bottom down programming was the best
approach.
• Data presentation helps in detecting errors
faster and avoiding problems.
• Placing UAV on a map helps discovering
its location.
• Tester helps in testing the response of the
RF and the pic programs
