How Drones Work

How Drones Work?

You probably have seen more discussions on drone use often than ever and are considering getting one. But before you do that, it’s imperative to understand how drones work.

Drones are Unmanned Aerial Vehicles (UAVs). They’re small or medium-sized vehicles that can be operated remotely or autonomously.

They have several features that make them fly and stay in the air for a specific time. To fly drones, you can use Apps, controllers, or joysticks.

The drone’s essential parts include the flight controller and the operating system. Also, sensors, batteries, cameras, electronic speed controllers, and propellers are vital as they enhance the drone’s functionality.

Keep reading to learn how all these components work together to ensure drone flight..

What are Drones?

Drones are Unmanned Aerial Vehicles (UAVs). They’re small or medium-sized devices operated remotely or autonomously.

They feature modern equipment, for example, high-resolution cameras, GPS, infrared, and radar control, which aids in keeping them in the right flight mode.

Due to the technology involved in designing them, drones can fly high, hover, descend, and turn.

One of the most amazing things about drones is that they easily access areas that could be difficult or life-threatening for pilots to access. For example, drones can save lives by identifying the number of people trapped under rubble after a building collapses.

They can also access certain areas after a deadly earthquake if the areas affected are yet to be confirmed safe for human entry.

Therefore, more than ever, drone application is increasing. Some drone applications include:

  • Surveillance
  • Traffic monitoring
  • Search and Rescue missions
  • Airspace defense by the military
  • Irrigation systems, pesticide application, and planting and harvest monitoring.
  • Archaeological inspections
  • Aerial photography

The History of Drones

The History of Drones

In the early 1900s, drones were only available to military officers and were used during wars. These drones were considered cruise missiles and had camera units and sensors. Since they were used in wars, they were not expected to return ‘home.’

Some of these drones were radio-controlled and were primarily used for target practice. Later, engineers developed Unmanned Aerial Vehicles (UAVs), which were loaded with munitions.

With time, though, drones became accessible to everyone, including hobbyists. So, today, drones are massively for personal use as well as for commercial purposes in a wide range of industries.

On the other hand, companies such as Amazon and Google are creating drones to ease parcel delivery tasks. Also, Facebook intends to develop drones for carrying signals to less developed areas.  

How Drones Work?

Power flows from the drone batteries to the rotor motors when you power on a drone.

Consequently, the propellers begin to spin to generate lift and beat the force of gravity, pushing the drone higher in the air as the pilot controls it.

Each propeller’s spin is relative to the other propellers responsible for changing the drone’s direction and altitude.

Every drone part plays a role in keeping the drone in the air. Technology advancement has even made it better for pilots as they can see what the drone sees from the ground.

So, to know how drones fly in the air, we need to look at their features in detail. These components include;

  • Propellers
  • Motor
  • Flight controller
  • Electronic Speed Controller
  • Battery
  • Frame
  • Camera
  • Sensors

Propellers

Propellers

Propellers rotate in different directions: clockwise (CW) and counter-clockwise (CCW). When propellers rotate, they generate lift and keep the drones in the air. A low-pressure zone is created when drone propellers rotate in different directions.

Consequently, air moves from low-pressure to high-pressure regions, hence making the drone move in different directions: backward, upwards, or forward.

On the other hand, for the drone to be dislodged into the air, the thrust generated balances when the drone is in the air, which helps keep the drone’s weight balanced. 

If the propellers are long, the drone can move slowly and carry heavy weight while creating a higher thrust.

The drone’s speed and ability to lift a load depends on its size, shape, and the number of propellers.

Below are the types of drones based on the number of their propellers:

  • Octocopter (8 propellers)
  • Hexacopter (6 propellers)
  • Quadcopter (4 propellers)
  • Triplecopter (3 propellers)
  • Bicopter (2 propellers)

Most pilots prefer using quadcopters.

Motors

Motors

Drone motors are classified into two: brushless and brushed. The brushless motors are more expensive but powerful.

However, they’re also energy efficient. They’re commonly found in drones used for aerial photography and videography, racing, traffic surveys, and freestyle.

These drone motors require an Electronic Speed ​​Controller (ESC) to control their speed effectively. On the other hand, brushed motors are cheaper and used mainly in small drones.

Flight Controller

Flight Controller

Drones use flight controllers to sense objects, communicate with pilots and computer systems, and control the drone based on the instructions given.

A flight controller may be called the drone’s actual brain. It’s a circuit board with some electronic chips, but it comes in varying complexity and size based on the drone’s purpose.

It uses different transmitters to strike a balance between telecommunication and balance controls.

Electronic Speed Controller (Esc)

Electronic Speed Controller

ESC converts the flight controller signals to the drone motor’s Revolution Per Minute (RPM).  Each drone motor has an electronic speed controller.

The Electronic Speed Controller connects the battery to the drone’s electric motor to enhance the power supply.

Battery

Battery

The battery provides the drone engines with power to take off. The drone battery quality determines the total flight time of your drone, its stability, and speed.

Some of the battery types used in drones include Lithium-ion (Li-ion) batteries, Lithium polymer (Lipo) batteries, and Nickel-cadmium batteries.

However, Lithium polymer (Lipo) batteries are the most commonly used due to their quality and reliability.

These batteries have a polymer electrolyte that separates the anode and lithium-based cathode. The Lipo batteries are lightweight and have a high current resistance.

Made from highly conductive semi-solid (gel) polymers and multiple batteries that use lithium-ion technology, electrolytes store a high amount of energy in a lightweight, compact package.

Instead of using liquid electrolytes, lithium batteries use lithium-ion technology, which uses polymer electrolytes. These lithium polymer batteries are rechargeable.

Camera

Camera

Drones with cameras give pilots an aerial view of areas that would otherwise be difficult to see from the ground. Hence, pilots don’t need a direct line of sight to see their drones.

Such drones are used in search and rescue missions, surveillance, agricultural fields, freestyling, weather monitoring, and firefighting, among other areas.

Gimbal cameras are used mainly in drones. These cameras move in all angles and directions to capture images or videos when the drones are in the air.

Frame

Frame

Drone frames house most of the drone components. Drone frames come in different materials, including carbon fiber, aluminum, fiberglass, and plastic.

For drones used to carry heavy loads, aluminum frames could be the best as they’re highly durable.

On the other hand, the carbon fiber frame is also strong. In addition, it’s lightweight and can also be used to make drone propellers. Nevertheless, drones made of carbon fiber tend to be highly-priced.

Buying a drone with a strong frame saves you a lot of money when it accidentally crashes.

Sensors

Sensors

Drone sensors help drones detect and avoid obstacles. Sensors may be called ‘minicomputers’ that collect information regarding the surroundings and send it to the flight controller.

Drones with sensors are highly sensitive to their surroundings and have excellent maneuvering ability, even in difficult terrains.

In return, the drone pilot can effectively stabilize the drone and avoid crashes.

There are various types of drone sensors, as we shall see below.

Gyroscopes

Accelerometers are used hand in hand with Gyroscopes to help the drone know its position and orientation in 3-dimensional space.

In addition, gyroscopes help the drone rotate at the position the user controls expect. Besides, they also measure and maintain orientation.

When the drone fails to receive any signals from the pilot, the gyroscopes begin to detect any drone wobbling or wayward drifting.

Instructions are then sent to the controller so that the motors can counteract any drone’s unwanted movements.

Detection of angular velocity by a Gyroscope sensor occurs in 3 axes. It detects the angle change rate:

  • Roll: Refers to the front to back axes rotation.
  • Pitch: Refers to the side-to-side axis rotation.
  • Yaw: Is the vertical axis rotation.

GPS Sensor

Drones can receive multiple GPS satellites from a GPS receiver. To know the drone’s position, the receiver can triangulate the drone’s relative position from multiple GPS satellites.

However, the time it takes for the GPS module to receive the signals differs based on the satellite source location and weather conditions. It will be slower to get enough satellites on a cloudy day compared to a clear day.

Also, GPS compares the target destination of the drone and its current position and decides the direction the drone should take, hence instructing its motors using commands.

The strength of the signal the GPS module receives, plus satellites available in its range, determines the accuracy of the location. 

GPS has also significantly contributed to the flying of drones in autonomous missions.

Accelerometers

During a flight, the accelerometers determine the drone’s orientation and position. Whenever the drone is in the stationary position, the accelerometers effectively determine the drone’s tilt angle. They also give the drone’s acceleration force in the X, Y, and Z axes.

When the drone tilts, the Z, Y, and X axes give a 0 to 1G output. The Y and X axes provide a zero-G output when the drone stays horizontally. The Z-axis output, though, is 1g, which every object on Earth experiences.

The X and Z axes give an output of 0g when the drone rotates at 90 degrees. The Y-axis, on the other hand, gives an output of 1g.

The data collected is essential in calculating the altitude change rate, velocity, and drone movement.

With accelerometers, drones can effectively detect the obstacles around them and evade them.

In addition, the accelerometers help drones navigate their environment and, remain stable and hover successfully.

Most drones use the Micro-Electro-Mechanical System accelerometer, abbreviated as the MEMS. It’s lightweight yet cost-effective.

This small accelerometer is powerful enough to detect acceleration in the X, Y, and Z axes. Besides, it can also measure small acceleration changes, even as little as 0.001g.

Barometric sensors

Barometric sensors are used in various devices, including smartphones, drones, and smartwatches.

In drones, these sensors measure atmospheric pressure. The barometric sensors may sometimes be referred to as pressure sensors.

In drone technology, they’re used as altitude sensors. Due to the barometric sensors, drones hover correctly to offer excellent aerial videos and photographs.

Besides, drones with barometric pressure sensors fly precisely when the gyroscope and accelerometer are combined.

Magnetometers

Magnetic sensors can detect the direction and surrounding magnetism. In addition, they sense ferrous metals, including other cars, drones flying nearby, electricity poles, and wires, and avoid them, preventing collisions.

Magnetometers provide X, Y, and Z axes of magnetic field data, which includes the direction and intensity of the magnetic field.

Consequently, the drone knows the magnetic North and can change its direction as required.

Drone LED Lights

Drone LED Lights

LED lights show the status of the drone. For example, they could notify you of a poor GPS connection and low battery. Below are the colors used to show the status of the drone.

Yellow/Orange: Indicates the GPS connection or the drone compass calibration is poor; hence, it requires correction.

Green: This color could mean the GPS has successfully connected to several satellites. Green could also mean the drone batteries and every other component are fit for take-off.

Purple: The drone lights turn purple to show that the ‘Follow Me’ or the ‘Return to Home’ (RTH) modes work as required. Some drones may use a purple LED light to show the AP status mode.

However, if the LED lights are blinking purple, the RTH, follow me, or AP modes could have an issue and must be checked before take-off.

White: Several issues could cause your drone LED lights to blink white; for example, the transmitter being off and poor or lack of GPS connection.

Red: The agility or RTH modes could have issues when the drone’s LED lights turn red. The drone battery could also be too low for a successful flight. There could also be other system errors, for example, an IMU error.

Blue: This color could mean the drone is stable or in blind mode.

Even so, the drone’s LED lights’ color meanings could differ based on your drone type. Hence, consider looking at the drone manual guide for the actual color meanings.

Navigation/Anti-Collision Lights: Depending on the drone model you own, the anti-collision lights can be red, blue, or white.

They may or may not flash. Navigation LED lights help pilots see the drone clearly and control it accordingly to avoid accidents.

You see the navigation lights from far away when a drone flies near your home at night. The FAA requires navigation lights on the drone if it’s used at night.

More Advanced Technology

More Advanced Technology

Unlike the drones that were first introduced in the 1900s, which had only a few components, today’s drones are highly advanced. Some of the advanced components found in today’s drones include:

  • Ground Control Station (GCS)
  • Data links

Ground Control Station (GCS)

GCS are a set of software and hardware that are ground-based. They enable the pilots to communicate efficiently with the drones to control them effectively.

So, pilots set the parameters by directly controlling the unmanned aerial vehicle (UAV) or for autonomous drone operation.

The Ground Control Station rover determines the easting, point of elevation, and northing. They also help establish accuracy when engaging in projects like mapping where the drone’s GPS may not be enough.

Data Links

To transmit data and receive information from the UAV, data links typically use Radio Frequency (RF).

The three main components of drone data links that are used in the UAV operation include:

  • Telemetry
  • UAV Control
  • Video Transmission

The data received and transmitted may include:

  • Distance from the drone to the pilot
  • Payload information
  • Live video
  • The remaining flight time
  • Flight altitude
  • Pilot location
  • Airspeed
  • Target distance and location

Some of the radio frequencies data link system uses include:

3 GHZ: Easily penetrates obstacles

4 GHZ: Sometimes maybe overcrowded because it’s largely used.

8 GHZ: It’s the shortest range

900 Mhz: Can penetrate obstructions

Conclusion

If you’re planning to own a  drone or already have one but want to know how this advanced technology works, this article is for you. It’s even better and more exciting to fly a drone with a complete understanding of how each part operates.

Modern drones’ propellers, motors, flight controllers, electronic speed controllers, batteries, frames, cameras, sensors, and other features aim to give you an exceptional flight.

The more advanced the drone is, the better it is. In addition, the features available in a drone also determine its purpose.

Drones with cameras are commonly used in aerial videography and photography, surveillance, search and rescue missions, agricultural projects, and military forces, among other areas.

Author
Peter Karanja

Peter is a licensed drone pilot and drone fanatic. He owns a DJI Air 2S that he uses to shoot videos for fun, enjoyment and for clients.

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