How to build your own QuadrocopterHow to build your own Quadrocopter
Lenz Grimmer <[email protected]>http://www.lenzg.net/
Twitter: @lenzgr
SAPO Codebits 2010, Lisbon, Portugal
OutlineOutline
● Basics / Operational Theory● Building Blocks● References/URLs● Demo
FeaturesFeatures
● A “VTOL UAV”● Simple to build● Simple mechanics ● No servos required● Parts Availability / Accessibility
Lab/Tech RequirementsLab/Tech Requirements
● Soldering station● Powerdrill / Dremel● Others (Screwdrivers, Saws, Files)● Power supply
Operational theoryOperational theory
● Physics● Flight Dynamics● Movement / Control
PhysicsPhysics
● 2 pairs of counter rotating props● Compensate rotary momentum● Different RPMs = different thrust
Flight DynamicsFlight Dynamics
http://en.wikipedia.org/wiki/File:Flight_dynamics_with_text.png
Movement/ControlMovement/Control
● Regular remote control● Behaves like a helicopter
● Nick / Roll / Yaw● Up / Down
● “X”, “+” or “Y” flight configuration● Pilot skills
Momentum CompensationMomentum Compensation
Yaw/RotationYaw/Rotation
Vertical MovementVertical MovementF F
FF
m·g
4⋅F=m⋅g
4⋅Fm⋅g
4⋅Fm⋅g
Ascending
Descending
Nick/RollNick/Roll
F1 F2
Nick/RollNick/Roll
F1F2
Building blocksBuilding blocks
● Frame● Motors● Propellers● Battery● Electronics
FrameFrame
FrameFrame
● Center plate● Arms● Battery mount● Motor mounts● Protective dome● Landing gear
PropellersPropellers
PropellersPropellers
● Diameter: 8, 10, 12 inch● 2 blades● Directly attached to motor● 2 each rotating CW and CCW● Proper balance reduces vibrations
MotorsMotors
Brushed MotorBrushed Motor
+ -
Brushless MotorBrushless Motor
Phase A
Phase C
Phase B
MotorsMotors
● Brushless● Outrunner vs. Inrunner● Direct drive (no transmission)● 3-phase powered● Requires special BL controller● Weight (g) / RPMs/V / max. current (A)
Brushless ControllerBrushless Controller
Brushless ControllerBrushless Controller● Converts DC power to 3-phase AC signal
● Drive motor to indicated RPMs
● Controller speed is essential
● Receives RPM info from receiver/control unit● PWM signal● I2C● UART (Serial)
BatteryBattery
BatteryBattery
● Lithium Polymer (LiPo) (or Lithium Iron Phosphate, LiFePo4)
● Lightweight● High currents and capacity● Handle with care!● Voltage / Capacity / Max discharge / Weight
Power Distribution / WiringPower Distribution / Wiring
Battery
Motor
BLC
SensorsMotor
BLC
Motor
BLC
Motor
BLC
RX
Central Control
Power DistributionPower Distribution
Power DistributionPower Distribution
● Supply the BLCs / Motors● Supply the central controller / Sensors● Support high currents● Main switch or battery plugs● Wires or PCB
Transmitter / ReceiverTransmitter / Receiver
Transmitter / ReceiverTransmitter / Receiver
● Frequencies: 35/40 MHz, 2.4 GHz● Minimum: 4 channels● Receiver output: PPM (sum signal) or individual channels from receiver (PWM)
SensorsSensors
SensorsSensors
● IMU● Gyroscopes (Rotation)● Accelerometers (Movement)
● Optional● Pressure Sensor (Altitude)● Compass/Magnetometer (Attitude)● GPS (Location)
Central ControllerCentral Controller
Central ControllerCentral Controller
● Collects sensor data● Receives control commands● Calculates orientation/location● Sends updated motor commands to BLCs
● Microcontroller (e.g. Arduino, ARM...)
Configuration SoftwareConfiguration Software
AccessoriesAccessories
● Camera mount● Zigbee for telemetry data● Video goggles
Legal aspectsLegal aspects
● Check local laws for regulations● Consider getting an insurance
Practical tipsPractical tips● Double-check propeller positions and directions
● Double-check Flight Control orientation
● Avoid vibration where possible for stable flight
● Test outside, away from people
● Don't attach the propellers on the motors until everything is tested!
References / URLsReferences / URLs● Forums
● RCGroups - http://www.rcgroups.com/
● DIYDrones - http://diydrones.com/
● Portuguese Forum - http://forum.rcmpt.com/
● Projects
● Mikrokopter - http://www.mikrokopter.de/
● UAVP-NG - http://ng.uavp.ch/
● Arm-O-Kopter - http://www.armokopter.at/
● Arducopter - http://code.google.com/p/arducopter/
● Aeroquad - http://aeroquad.com/
● KK-Multicopter - http://kkmulticopter.com/
● OpenPilot - http://openpilot.org/
● Quadrocopter and Tricopter Info Mega Link Indexhttp://www.rcgroups.com/forums/showthread.php?t=1097355
References / URLsReferences / URLs
● Parts● HobbyKing -
http://www.hobbyking.com/● SparkFun - http://www.sparkfun.com/● DIYdrones - http://store.diydrones.com/
Recommended
