5. An aircraft that is lifted and propelled by four
propellers.
Control and maneuvering is achieved by
varying the relative speeds of the four
rotors.
Vertical Take Off and Landing
7. PRO-E simulation was used to determine:
Dimensions of the craft (0.25 m).
Total mass (1.5 kg) of the PVC structure
Moment of inertia (0.025 kg.m2) .
Propeller size (9 inch).
The results obtained enabled us to select a suitable BLDC motor for the
quad rotor.
9. BLDC motor - out runner (the outer shell spins) is used
Specifications:
Weight: 56g
Voltage: 10V
KV: 1200 RPM/V
Max Efficiency Current: 15.5A
Max Power out: 180W.
An electronic speed controller (ESC) is used
to control the speed of electric motors.
It is a pulse-width modulation (PWM) controller
Turnigy Bell 2409-18T
10. Two 2200mAh 3S 25C Lipo Packs and a separate
battery used for electronic circuitry.
Size: 9 x 5
Clockwise and Counter-Clockwise orientation.
11. dsPIC 30f5015 motor control series microcontroller
for onboard computation.
All calculations were done in fixed point (signed Q15.16)
Capable of providing 4 simultaneous independent PWM’s
dsPIC features, hardware multiplier, 16 bit architecture
Operating with a clock multiplier to obtain 14MIPS.
13. IMU data is corrupted and has to be filtered to make it usable.
Gyro integration gives orientation but drifts over time.
14. Accelerometer gives the gravity vector.
Integration of rate gyros gives attitude.
Noise in gyros:
Offset
White noise
Leads to drift
The ‘g’ reference vector from the accelerometer is used to correct this drift
15. The gyro is integrated to give the roll and pitch.
obtain the calculated ‘g’ vector.
The error between the measured and calculated ‘g’ vector is adjusted into the
gyro data.
Gyroscope
(rad/unit time)
Compensation
Roll/Pitch
angle
Accelerometer
(rad/unit time)
Error PID
Cross Product
Integration
Estimated ‘g’
vector
17. Two options for orientation estimation
The Complimentary Filter:
does not require the system model
is optimized for microcontroller implementation
performance is comparable to the Kalman Filter
Kalman filter Complimentary filter
18. PID controller was used for roll and pitch control.
Larger P leads to faster response,
I used for reference tracking
D dampens the oscillations, reduces overshoot
A simulation was done using the mathematical model in MATLAB.
The gains found were fine tuned on the actual system
19. Objective:
Sensing translation in X- axis
Sensing translation in Y- axis
Yaw computation
20. Wireless camera over IP are very expensive.
Camera of the smart phone was used for live streaming.
Bluetooth link was used between the camera and the base station.
A Red Cross of the ground was used as reference for determining
the position of the craft.