A Beginners Guide to Drones
Types, Components and Uses of Drones
When I say the word “Drone” what’s the first thought that comes to mind? Is it a high-tech military aircraft that can spy from across the globe or is it a small aircraft with a camera?
Well, as it turns out, both of those are drones!
Drone [drōn]: An uncrewed aircraft or ship guided by remote control or onboard computers
The term drone is used to refer to an Unmanned Aerial Vehicle (UAV). A UAV pretty much means what it stands for; it’s a flying vehicle which is remotely operated by a human or computer.
Types of Drones
There are several different types of drones, ranging from single-rotor drones to fixed winged drones.
Single-Rotor
These drones look quite similar to a helicopter because they have, you guessed it, one rotor.
Multi-Rotor
These drones have, you guessed it, multiple rotors. Having multiple rotors helps to improve stability and maneuverability. Often times the number of rotors will range from 4–8 with some even having 12 or 16!
Fixed-Winged
These drones are similar to a conventional aircraft because they have a large pair of wings which help to keep them afloat, and a motor to keep them moving forwards. Fixed-winged drones are often used in scenarios where long flight time is necessary.
Hybrid Fixed-Wing
These drones are a cross between fixed-winged and rotor drones. Hybrid drones take the benefits of both and can perform vertical liftoffs as well as stay in the air for extended periods of time.
Components
There are several different components that make up a drone.
For a quadrocopter (4 rotors), the components include:
Frame
The frame provides the support and structure for the whole drone. It is usually made of a light material, such as carbon fiber or plastic. It also provides a mounting point for the electrical components to be attached to.
Propellers
Paired with a motor, the propellers, or rotors, provide the lift needed to fly the drone. The propellers can be spun at different speeds to cause the drone to maneuver in different ways. Drone propellers are usually made of either plastic or carbon fiber.
Motors
The motors rotate the propellers at high speeds to enable flight. There are two types of motors: brushed and brushless. Brushless motors have a higher efficiency due to the elimination of friction, which allows for longer battery life and reduced overheating.
Electronic Speed Controllers (ESC)
The ESC controls the rotational speed of the motors. It acts as an intermediate between the flight controller and the motor. It enables the speed of the motors to decrease or increase, thus allowing the drone to maneuver in the air.
Power Distribution Board (PDB)
The PDB acts as an intermediate between the battery and the electronics. Its job is to distribute the voltage from the battery across the various other electronic components.
Global Positioning System (GPS) Module
The GPS provides accurate information of several aspects of the drone’s position such as the compass heading, elevation and location. The GPS also helps make the drone flight safer by maintaining its location.
Transmitter + Receiver
The receiver receives (obviously) the input given by the transmitter and relays it to the flight controller. The transmitter and receiver are usually radio controllers which have multiple channels that control the different movements of the drone (throttle, yaw, pitch and roll).
Flight Controller
The flight controller connects all the inputs and outputs of the drone in one central location. It communicates with the motors and other sensors to make sure the drone is stable in the air and is able to follow the orders given by the drone operator. In that sense, it acts as the “brain” of the drone.
Battery
The battery is used as a power source for the motors, and any other electronics on board. Lithium Polymer batteries are the most common type of battery used for drones due to their high energy density, discharge rates and small form factor.
Other components
The drone may be equipped with several other parts or sensors such as a camera, gimbal, thermal sensors and infrared sensors. These are mostly optional but can add to the experience and capability of the drone.
How a Drone Flies
Alright, lets get technical. How exactly does a quadrocopter fly and maneuver in the air?
Motor Setup
The motors in a quadrocopter are set up such that two motors always rotate counter clockwise, while the other two rotate clockwise.
This setup allows the drone to stay stable in the air because the angular momentum of each propeller cancels out.
Moving Vertically (Pitch)
Moving vertically is perhaps the easiest task for a drone. When the propellers spin fast enough, air is pushed down, causing the air to also push back up on the propeller creating lift.
When the drone hovers, the upwards thrust of the drone must be equal to that of the gravity pulling the drone to the ground.
When moving up, the thrust must be increased (spinning all the propellers faster) such that the upwards thrust is greater than gravity pulling the drown down.
When moving downwards, simply decreasing the thrust (spinning all the propellers slower) such that the net force is downwards will allow the drone to descend.
Moving Horizontally/Forwards (Roll)
For a drone, moving side to side and forward to back are similar because the drone is symmetrical, meaning it employs the same mechanics.
When moving a the drone to the right, for example, by increasing the speed of motors 1 and 3 in the above diagram, and decreasing the speed of motors 2 and 4, the net upwards thrust stays the same (decreasing two motors while increasing the other two) but thrust is more angled now. This causes the drone to move to the right while staying at the same height.
This same idea applies to moving the drone in any other direction.
Turning (Yaw)
The next basic form of movement a drone does is turning to the left and right. This is where the drone motor’s clockwise/anti-clockwise setup plays the key role.
When the drone is hovering, the angular momentum from motors 1 and 3 (clockwise) cancel out the angular momentum from 2 and 4 (anti-clockwise) thus making zero net movement.
When rotating to the right, if both motors 1 and 3 were to reduce thrust, the angular momentum of those motors would also decrease, causing the drone to turn clockwise. To maintain the same height, motors 2 and 4 must increase thrust, thus causing the drone to rotate to the right at the same height.
When rotating to the left, the same idea is applied but with decreasing the thrust for 2 and 4, while increasing for 1 and 3.
Applications of Drones
Ok, that’s cool and all, but where are drones actually used in the real world?
Turns out, they have several different uses spanning many industries. Here are a few:
Filmmaking
Slap a camera with a gimbal on a drone, and you’ve got a cost effective method of aerial filming. Commercial films no longer have to use expensive helicopters or dollies to film shots from the air, and can instead use drones to capture the same shot. This also gives the opportunity for amateur film makers to capture previously impossible shots.
Military
The military uses drones for surveillance or precision attacks when a manned aircraft may be too dangerous. These drones often have powerful cameras and can be outfitted with missiles. Drones in the military are considered the future of warfare by many due to the unmanned nature of the aircraft.
Surveying
Commercial drones with cameras are often used to monitor agriculture, pipelines and other infrastructure. The drone’s ability to quickly reach high risk areas and take high quality photos and videos is valuable for companies to asses damage or monitor sights. Drones can also be outfitted with an array of sensors, such as lidar and thermal cameras, to create 3D models of areas and survey with more information.
Package Delivery
Drones can be used to ship packages from location to location. Companies like Amazon, Walmart and DHL are looking into using drones for last-mile deliveries from warehouses to the recipient’s houses. Drone delivery can speed up package shipping and reduce costs for companies.
Racing
Competitive drone racing is a sport where operators fly drones through a set course. The course can be very complicated and requires operators to perform advanced maneuvers. The drones are built with an emphasis placed on speed and agility.
Final Thoughts
Personally, drones have always fascinated me, and I plan on building one in the near future. Stay tuned for a full breakdown of the drone I build!
Thanks for reading!
Feel free to connect with me:
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Email: vikrammenon03@gmail.com
