Drone Flight Control-Electronical Engineering-Systems And Controls
ELEC 341 Project, 2015 – Drone Flight Control
An Apache helicopter drone has electric main and tail rotors.
The main rotor induces lift and yaw, due to air drag, and the
tail rotor counteracts the main rotor yaw to control rotation.
Model the drone and control it to follow a prescribed flight
path which includes take-off, ascent, half rotation (yaw),
descent, and landing. The goal of your PID control system is
to minimize the error between the desired and actual height
and yaw angle. After take-off, the wheels MUST not touch
the ground until it lands.
For each rotor, a PID controller drives a voltage amplifier
which applies a voltage to the motor. A reduction gear is
connected to the main motor but the tail motor is direct-drive.
Altitude and yaw GPS sensors provide feedback control.
Desired Trajectory
• Altitude is input in units of meters
• Angle is input in units of degrees
Main Motor Specifications:
• The inductance is 120 mH
• The internal resistance is 500 m?
• The torque constant is 45 mNm/A
• The back-EMF constant is 410 RPM/V
• The inertia is 70 gcm2
• The friction is 20 gcm2/s
• The weight is 300 g
Main Gear Specifications:
• The inertia is 140 gcm2
• The friction is 55 gcm2/s
• The reduction ratio is 12:1
• The weight is 325 g
Main Rotor Specifications:
• The rotor contains 4 blades
• Each blade is 12 cm long
• Each blade weighs 15 g
• Air friction losses are 370 gcm2/s per blade (This torque is
counteracted by the tail rotor to keep the drone from rotating)
• Each blade produces 6500 mg/RPM of axial thrust
Tail Motor Specifications:
• The inductance is 72 mH
• The internal resistance is 350 m?
• The torque constant is 22 mNm/A
• The back-EMF constant is 16 RPM/V
Yaw
Main Rotor Tail
Rotor
Lift
ECE 360 Project – Page 2 of 3
• The inertia is 45 gcm2
• The friction is 11 gcm2/s
• The weight is 180 g
Tail Rotor Specifications:
• The rotor contains 4 blades
• Each blade is 5 cm long
• Each blade weighs 4 g
• Air friction losses are 95 gcm2/s for the entire rotor
• Each blade produces 22 mg/RPM of axial thrust
Drone Specifications:
• The mass of the helicopter body is 175 g
• The vertical air resistance of the helicopter is 0.0125 Ns/cm
• The distance between the shafts of the main and tail rotor is 18 cm
• The helicopter has a moment of inertia of 25,000 gcm2
• The helicopter has rotational air friction of 22,000 gcm2/s.
• The GPS sensor outputs 1V/ft (altitude) to Vin in the circuit shown
• The GPS sensor outputs 1V/rad (yaw) to Vin in the circuit shown
Controller & Amplifier Specifications
• The voltage amplifier is modeled as shown.
General Information:
• The model was created using Matlab Version R2014b.
• You may use any Matlab functions to complete this project. Include all Matlab scripts and output in your report. The control
toolbox (help control) is useful for solving transfer functions, drawing a root locus or nyquist plot, etc.
• You are provided with a Simulink model (apache.mdl & apache.wrl) and two Matlab scripts (constants.m & setup.m).
The “constants.m” script initializes the constants specified in this document. The “setup.m” script is where you calculate
the values for each of the shaded blocks. BE SURE TO KEEP TRACK OF PHYSICAL UNITS in “setup.m”. Write them
in as comments.
How to Complete this Project:
• Determine the system model.
• Pay extra attention to the physical units of the signals in the system model.
• Compute the models for each block in your “setup.m” script.
• Evaluate the system (transfer function, order, poles/zeros, time constant, etc.). Anything that is too complex to solve
analytically may be done experimentally.
• Design your PID controllers.
• Compute the open-loop gain of each sub-system. Ignore the saturation blocks. These are non-linear constraints that
you cannot model and must compensate with some fine-tuning.
• Use the techniques you learned in class to choose starting values for your controllers.
• Tune your controllers to optimize the step/impulse responses. Both rotors are MISO systems. Use superposition.
• You may not use the PID “Tune” function to tune your PID controller.
• A “SCORE” is computed from your error values and is displayed in a window on the Simulink model. Fine-tune the integrated
system to minimize your “SCORE” and ensure all constraints are satisfied.
Vin Vout
15V
–15V
L1
1.5H
L2
R 2.5H 1
6?
C1
15mF
R2
100?
Vin Vout
15V
–15V
L3
100mH
R3
1?
L4
50mH
R4
2?
Vin Vout
15V
–15V
L5
60mH
R5
2?
L6
45mH
R6
6?
GPS Altitude Sensor
GPS Yaw Sensor
Current Amplifier
Controller &
Amplifier
Gear &
Rotor
Helicopter
• The blocks in the model are shaded as follows:
Motor
ECE 360 Project – Page 3 of 3
Deliverables:
Part 1: System model file (setup.m) + calculations + description (calc.pdf)
1. Hand written calculations are ok as long as they are VERY neat
• Show how each block in your system model was computed.
• Obvious calculations can be included in the comments of “setup.m” (eg. converting g to Kg)
• A description of your system (transfer function, order, poles & zeros, dominant poles, root locus, time const., etc.)
2. Email the following to the Project TA (NOT the instructor) by the project due date:
• A copy of your “setup.m” file.
• A PDF of your calculations and system description report.
Part 2: System Control
1. Describe the steps you took to design your PID controllers:
• Strategy
• Starting Point
• Tuning Process – show a few intermediate results
• Conclusion – what you learned during the tuning process
2. Email the following to the Project TA (NOT the instructor) by the project due date:
• A PDF copy of your PID tuning report
• Include a scan of all hand-written work
• Include a title page containing
• The names & student number of all team members
• Your final PID gains + the resulting SCORE
3. Your system must meet the following criteria for the “Best Score” competition:
• Simulation / Configuration Parameters / Solver = ode45 (Dormand-Prince).
• PID blocks: Derivative divisor (N) = 100. Refer to the project web page for a description of this parameter.
• PID values may not contain more than 3 significant figures (trailing zeros are ok)
• No blocks may be added or deleted (scope blocks may be added but not deleted).
• The winning system will by checked by running the submitted “setup.m” file with the original system.
Grading:
• This project is worth 25% of your final grade.
• BOTH the printed report and email must be received by the due date or the report will be considered late.
• All LATE reports will be marked PASS/FAIL (PASS = 50%, FAIL = 0%).
• If you do not get a passing grade on this project, ALL OF YOUR QUIZ MARKS WILL COUNT.
• You may work in teams of 1 or 2. Submit 1 report per team. Both team members receive the same grade.
• The team that completes the task with the lowest “SCORE” will receive FULL MARKS (15%) for Part 2.
10% Part 1:
• 50% system model values (including physical units)
• 25% system model calculations
• 25% system description
15% Part 2:
• 10% Strategy
• 10% Starting Point
• 75% Tuning Process
• 5% Conclusion