How to build your own Quadrocopter

How to build your own QuadrocopterHow to build your own Quadrocopter

Lenz Grimmer <lenz@grimmer.com>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/