Monday, September 21, 2015

How I Made a Drone

TerminologyTypes

ARF
Almost Ready to Fly“: a UAV which comes assembled with almost all parts necessary to fly. Components like the controller and receiver may not be included.
BNF
"Bind and Fly“; the UAV comes fully assembled and includes a receiver. You only need to choose a compatible transmitter and “bind” it to the receiver.
DIY
Do It Yourself“, which is now commonly used to mean “custom”. This normally involves using parts from a variety of different suppliers and creating or modifying parts.
Drone
This is synonymous with UAV. The term “drone” seems to be more common for military use whereas “UAV” is more common for hobby use

Hexacopter

A UAV which has six motors / propellers.

Multirotor

“Multirotor” simply means an aircraft with multiple rotors

Octocopter

A UAV which has eight motors / propellers.
Quadcopter

A UAV which has four motors / propellers and four support arms. Configurations are normally “+” (the front of the UAV faces one of the arms) or “X” (the front of the aircraft faces between two arms).
RTFReady To Fly“: a UAV which comes fully assembled with all necessary parts. Simply charge the battery and fly!

Size (mm)
“Size” is normally provided in millimeters (ex 450mm) and represents the 

greatest point to point distance between two motors on a UAV. Size can also determine the “class” of UAV (micro, mini etc)
Spyder
A “Spyder” type UAV (normally quad or hex) is one where the supporting arms are not symmetric in bot haxes when looked at from the top.

Tricopter

A UAV which has three motors / propellers, and usually three support arms

UAV

Unmanned Aerial Vehicle” (of any kind)

V-Tail

A UAV which has four arms, of which the rear two are at an angle to form a ‘V’
X4 / X8

X4 and X8 are UAV configurations with four support arms; X4 configurations have one motor at the end of each arm, whereas X8 have two motors per arm (one facing up, the other facing down)
Y3 / Y6

Y3 and Y6 are UAV configurations with three support arms; Y3 configurations have one motor at the end of each arm, whereas Y6 have two motors per arm (one facing up, the other facing down)
Quadcopter
Quadcopter
V-Tail
V-Tail
Octocopter
Octocopter Frame
Mechanics
CGCenter of Gravity“; this is the point on the aircraft where there is equal weight distributed on all sides.
Clamp
A “tube clamp” is a device normally used on a round tube in order to connect it to another device (such as a motor mount or a UAV’s body).

Connectors
In order to plug and unplug wires, connectors are used at the ends of wires. 

Common connectors for batteries are Deans & XT60, while connectors for the flight controller and sensors are 0.1″ spaced
Dampeners
These are molded rubber parts used to minimize vibration transmitted throughout a UAV
Frame

The frame is like the “skeleton” of the aircraft and holds all of the parts together. Simple frames have motors connected to aluminum or other lightweight extrusions (“arm”) which then connect to a central body.
G10
This is a material commonly used instead of carbon fiber to make a UAV’s frame since it is very rigid and lightweight, but significantly less expensive
Landing 

Gear

Multirotor landing gear normally does not have wheels as you might find on an 

airplane – this is to prevent it from moving when on the ground and reduce overall weight.
LED
Light Emitting Diode“. These are used to make the UAV visible, primarily at night or low lighting conditions.
Prop Guards
“Propeller guards” are material which curround a propeller to prevent the propeller from contacting other objects. They are implemented as a safety feature and a way to minimize damage to the UAV
Retract

“Retractable” normally refers to landing gear which has two positions: one for landing and takeoff, and another, which takes up less room or improves visibility, during flight.
Shell

This is an aesthetic / functional cover used to improve resistance to the elements and sometimes improve aerodynamics. Some production UAVs only have a plastic shell which also acts as the “frame”.

DampenerAnti-Vibration         Dampener
Landing Gear
Simple Landing Gear
UAV Shell
            UAV Shell

Propulsion

BECBattery Eliminator Circuit“: a voltage regulator built into the ESC which can provide regulated 5V DC power to any electronics which need it.
Blades
Propeller blades are the aerodynamic surface which generates lift. A propeller normally has two to four blades which can be fixed or folding.
CW / CCW

CW indicates Clockwise rotation and CCW indicates Counter-Clockwise rotation. On a multi-rotor aircraft, you would normally use pairs of counter-rotating propellers.
ESC

Electronic Speed Controller” is the device which connects to the battery, motor and flight controller and controls the speed at which the motor rotates
LiPo


Lithium Polymer” is the most common battery used in drones and UAVs because of its light weight (versus storage capacity) and high current discharge rates.
There are other types of Lithium-based batteries available on the market as well (LiFe, LiMn, LiOn etc)
Motor

The motor is what is used to rotate the propellers; in small UAVs, a brushed motor is most often used, whereas for larger UAVs, a “brushless” motor is much more common
PCB
A “Printed Circuit Board” is the flat fiberglass part with many components soldered to it. Many electronic products have a PCB.
PowerDistribution




In order to power so many different devices used in a UAV, the battery must be split, which is where the Power Distribution (board or cable) comes into play.
It takes the single positive and negative terminals of the battery and provides many different terminals / connection points to which other devices (operating at the same voltage) can receive power.
Propeller
The propellers are what provides the thrust and are more similar to those used in airplanes rather than onhelicopters.

Prop Adapter

A device used to connect the propeller to the motor.
Prop Saver

A type of hub which mounts on top of your motor and replaces the prop adapter. In he event of a crash, a part of the prop saver is lost in an attempt to save the propeller.
Servo
A servo is a type of actuator which, provided the right signal, can move to a specific angular position
Thrust

The “thrust” is the force which a specific motor and propeller can provide (at a certain voltage). Usually measured in kilograms (Kg) or pounds (Lbs)
LiPo Battery
LiPo Battery
Propellers
CW / CCW Propellers
Power Distribution
Power Distribution Board

Control

Base / ground /
Control Station
Instead of (or in addition to) a hand held transmitter, a station (normally in a case or mounted to a tripod) is used to house / integrate the necessary components used to control a UAV.
This can include the transmitter, antenna(e), video receiver, monitor, battery, computer and other devices.
Binding

The term “binding” refers to configuring a handheld transmitter so it can communicate with a receiver; if a transmitter came with a receiver, it should have been done at the factory.
Channel
The number of channels on a transmitter relates to the number of separate signals it can send
Flight Controller

The “Flight Controller” is what would be considered the “brain” of a UAV and handles all of the data processing, calculations and signals.
The core of a flight controller is often a programmable “microcontroller”. The flight controller may have multiple sensors onboard, including an accelerometer, gyroscope, barometer, compass, GPS etc.
If the flight controller has the ability to control the aircraft on its own (for example to navigate to specific GPS coordinates), it may be considered to be an “autopilot”.
Harness
This usually refers to the “Wiring Harness” which are the wires that connect the receiver to the flight controller (and sometimes other devices).

HF/ UHF / VHF

High Frequency“; “Very High Frequency” and “Ultra High Frequency” radio waves. Units are in Hz (Hertz)

Receiver

This is what processes the information received wirelessly

Sketch / Code

This is the program which is uploaded to your UAV’s flight controller (similar to a “thought process”)

Transmitter / Radio

The “transmitter” is what generates the control signal(s) wirelessly to the receiver
Base Station
Base Station
Transmitter
Transmitter
Flight Controller
Flight Controller

Sensors / Orientation

Accelerometer

An accelerometer measures linear acceleration in one to three axes. Units are normally in ‘g’ or gravity. An accelerometer can provide your drone’s orientation with respect to ground
Antenna

Antennas are what actually receive or send a signal to and from a UAV (the signal itself having been generated by a transmitter unit).
They come in a variety of different types and include directional (strongest in one direction) and omnidirectional

Barometer / Pressure  

/ Altimeter

A Barometer is used to give feedback as to the altitude of the UAV. It measures pressure, and since pressure changes with altitude, your aircraft can “know” its height.
Compass
A magnetic compass can provide your compass heading (north / south / east / west)
Flight Recorder
A flight recorder records sensor values from your UAV. This feature can sometimes be integrated into the flight controller.
GPS

Global Positioning System“: satellites orbiting the planet send out signals which are picked up by the GPS antenna and are sent to be processed by the GPS receiver to provide geographic coordinates
Gyroscope
A gyroscope measures angular acceleration in one ot three axes. Units are normally degrees per second squared.

IMU

Inertial Measurement Unit” combines an accerleometer and a gyroscope
MagenetometerIn low cost robotics, a magnetometer is sometimes used to provide compass direction
Pitch
Pitch is the angle of the nose to tail with respect to the ground, or in other words, the rotation of an aircraft about the axis from wing to wing

Pitot Tube

A device which measures air speed

Roll

Roll is the rotation of the aircraft along the axis from its nose to its tail
Yaw
Yaw is the rotation of an aircraft about an axis perpendicular (90 degrees to) to the plane formed between the nose / tail and wing tips
Roll Pitch Yaw
Roll / Pitch / Yaw
Airspeed Sensor
Airspeed Sensor
GPS
GPS Module

Video

FPVFirst Person View“: The UAV is mounted with a camera and the operator has a live video feed displayed on either a monitor or virtual reality glasses

Gimbal

A devices which carries a camera and is normally actuated using either a servo motor or a brushless DC motor. A gimbal is what can stabilize a camera in flight.
GoPro
The GoPro series of action cameras is widely used for taking and/or transmitting video
LCD
Liquid Crystal Display” is a type of screen / monitor used to display the image received by the receiver
OSD
On Screen Display” provides text on the monitor / screen which is being sent from the aircraft (can include altitude, GPS location etc.)
VR
Virtual Reality” glasses or goggles provide the operator with a more “immersive” experience
Gimbal
2-Axis Gimbal
FPV Monitor
LCD Monitor for FPV
VR Glasses
VR Glasses

Do you Really Want a Custom UAV?

The choice of UAV depends on how much you want to learn about the field. Building a custom UAV can be quite involved as well as dangerous. If you would prefer to simply “get in the air” quickly, we’d suggest the following, in increasing order of complexity:
Multi-rotor toys are becoming increasingly popular. Most are small, and can fit in the palm of your hand, though some like the A.R. Drone Parrot are larger. Toy multi-rotor UAVs are not necessarily easy to fly, but are more resistant to crashes. Toys tend to be smaller and integrate the frame into the aesthetic shell.
A “Ready To Fly” kit includes all the parts needed for a complete UAV. Parts include the UAV itself (most often pre-assembled and pre-wired), the hand held transmitter, a battery and charger. The craft is calibrated and should be able to fly with relative ease. These are not however indestructible, and a crash may damage the system to the point where it is simply worth buying a new aircraft rather than attempting to repair it.
An “almost ready to fly” kit is one where the frame, motors and most of the “core” parts are included and fully assembled (or a few parts need to be assembled, largely to help with shipping). Normally an ARF kit requires the addition of a transmitter / receiver and perhaps batteries and charger. Other ARF kits do not include the flight controller itself. You may need to do some calibration because of the additional parts required. We do not suggest a BNF kit as not all transmitters and receivers are compatible with one another.
A kit normally includes most of the important products needed to build a UAV, but may not include the transmitter / receiver, battery and charger or flight controller. Different kits have different package contents, so it is important to see exactly what is included and what additional items will be needed. The contents of a kit should be compatible with one another.
A custom setup is where you combine a variety of different products from a variety of different manufacturers and get them to work together. This approach requires that you understand which components are needed to make a UAV and will be the focus of this series of articles.

Do you see terms which are missing and would be useful? Feel free to add them in the comments below.