There are many different radio-controlled vehicles, from land-based racing cars to fixed-wing photography drones and everything in between. It can sometimes be hard to delineate between the remote-controlled flying aircraft, and you hear people call them by different names, such as “quadcopter” and “drone”. People often use these two terms interchangeably, although they are not synonymous with each other necessarily.
Drone refers to any uncrewed vehicle guided by remote control or onboard computers. A quadcopter is a more specific term for a flying drone that uses four rotors or propellers to fly. A quadcopter can be a drone if unmanned, but not all drones are quadcopters.
It is important to note that most people are familiar with the term drone from the rise of camera drones purchased by hobby and professional photographers. Others know the term drone from military aircraft that remotely attack foreign lands and are piloted remotely, sometimes from different countries.
In the diagram below, you will see examples of the different types of drones available. This diagram includes military drones, photography drones, agricultural drones, fixed-wing drones, underwater drones and many more radio or computer-controlled vehicles.
You will notice that quadcopter is a more specific term than a drone. It refers to a vehicle that is powered by four motors and propellers. These vehicles are often used for racing drones and photography drone purposes.
From the above hierarchy diagram, you’ll notice that a quadcopter can be called a drone, but not all drones can be called quadcopters.
What is a drone
According to the Merriam-Webster dictionary, a drone can be defined as:
- an uncrewed aircraft or ship guided by remote control or onboard computers.
You will notice that this definition does not include any specifications about how many motors are propelling the drone, the size of the drone, or how it travels. For example, if it travels via sea, air or land.
The term drone is a much broader classification that fits the above definition. It can look like an aeroplane, helicopter, motorcycle, boat, car, or any other mode of transport. It is a drone as long as it is unmanned and guided by remote control or software.
The history of the term drone is quite interesting.
The history of drones
The first pilotless vehicles were developed in Britain and the USA during World War II. According to the Imperial War Museum, Britain created a small radio-controlled aircraft first tested in March 1917. The American aerial torpedo known as the Kettering bug first flew in October 1918. Although both aircraft showed promise in their early test flights, they were not used operationally during the First World War.
Between the first and second world wars, the development and testing of unmanned aircraft continued. In 1935 the British produced several radio-controlled aircraft used as targets for training purposes.
It is thought that the term “drone” started to be used at this time, inspired by the name of the models used the DH.82B Queen Bee.
According to the Merriam Webster dictionary, the connection of this name with bees is that a drone is a stingless male bee that has the role of meeting with the Queen and does not gather nectar or pollen.
Since those initial drones were created, the field has blossomed into a vast ecosystem of different vehicles. Drones now have a variety of functions ranging from scientific purposes, search and rescue operations, photography, filming, and a controversial use in the military.
Here are some examples of different types of unmanned vehicles that can fall under “drones”.
Examples of drones
Despite the aerial nature of the first drones, they do not necessarily have to be airborne to be considered drones. There are plenty of examples of drones that travel on land and underwater drones that can accompany you on your scuba-diving trip.
Military drones are probably the most controversial type of drone that currently exists. The military uses aerial drones for reconnaissance, surveillance and highly targeted attacks.
Military drones also can carry weapons while being piloted from another country. The use of weapons on a drone has raised many questions about the ethics of weaponry. Because of the remote nature of the drone from the target, they may not be able to accurately pinpoint and identify bad agents, which can result in civilian deaths.
Nonetheless, the military will continue to use and develop military drones and software for competing against other countries military. The drone arms race will continue as long as it offers a strategic advantage.
Photography drones are what most people think about when you say the term drone.
A photography drone carries a camera into the air to capture aerial photos and videos of the surrounding area.
They can travel up to 10 km and retain radio contact with the pilot.
Drones are perfect for photography because they can fly smoothly and predictably through scenes. Taking photographs requires a highly stable camera suspended in the air. With the gimbal and other small motors keeping the drone stable, recording smooth footage using a drone is possible.
The photography drone market is dominated by a company called DJI which produces a range of camera drones for hobby photographers through enterprise and professional-level camera drones.
Other well-respected brands include Autel and Parrot.
Fixed-wing drones look like an aeroplane and fly using the same principle.
They pass air over their wings by continuously moving forward, creating a low-pressure system like a conventional aircraft. This low-pressure system keeps them in the air.
There are many different designs and wing shapes that impact the flying capabilities of the drone. There are three types of wings:
- Delta wing
- Swept wing
- Straight wing
Fixed-wing drones are used because they can fly for a very long time whilst using less energy. Fixed-wing drones are perfect for aerial surveillance and taking photographs of a large area.
They cannot hover like a photography drone because they need to move forward for maximum stability.
Unlike a drone with rotors, this requires a much higher skill level as you need to have a runway or catapult launcher to put the drone in the air.
A runway or a parachute is necessary to safely land back on the ground.
Fixed-wing hybrid drones are also available, which combines the energy efficiency of a fixed-wing drone with the vertical takeoff and landing capabilities of a drone with propellers.
Underwater drones are not readily talked about when referring to the term drone. An underwater drone is also called a UUV, an unmanned underwater vehicle.
These drones are typically controlled using a smartphone tethered directly to the underwater drone.
They can also communicate wirelessly through a Wi-Fi signal collected by a buoy above the drone floating on the water’s surface.
Underwater drones can reach a maximum depth of up to 150 m. However, because they rely on a physical tether to communicate with the pilot, most only travel about 30 m. Wi-Fi and other radio signals do not travel through water.
Underwater drones can be used by scuba divers who want to enhance the dive and scientists doing research. Without getting wet, aquaculture farms and people who want to inspect underwater assets can also utilise an underwater drone.
What is a quadcopter
According to Wikipedia, a quadcopter is a helicopter with four rotors.
Specifically, it is an aerial vehicle or rotorcraft (a vehicle that uses rotors for propulsion) with four arms, each with a propeller that spin clockwise and counterclockwise, enabling the craft to hover and maintain stability.
If you want a full rundown of how a quadcopter moves through the air and the intricate interplay between the four rotors, check out my other article – how does a drone change direction? – Where I go through all of the physics and diagrams that explain how a drone moves through 3D space.
Who invented the quadcopter?
The world’s first quadcopter was invented by Jacques and Louis Bréguet in 1907.
Gyroplane No.1 was one of the earliest attempts to create a rotary-wing aircraft. The aircraft had an uncovered open steel framework with a seat for the pilot and the powerplant at the centre.
On 29 September 1907, this gyroplane was flown for the first time to an elevation of 0.6 m. Four men on the ground were used to study the structure, and the quadcopter wasn’t controllable or steerable. However, it was the first time that a device like this had been in the air.
It later flew up to 1.5 m.
It had an endurance of one minute – far less than the 40 minutes of modern-day drones and quadcopters
Since that initial flight drone and quadcopter technology has improved significantly, we can now carry them in our pockets.
Why do people call quadcopters drones?
Are People call quadcopters drones because if they are unmanned, they classify them as drones. A drone is a less specific term for an unmanned vehicle. A quadcopter can be a drone, but not all drones are quadcopters.
Other people use drones and quadcopters interchangeably for consumer-level drones such as those manufactured by DJI and Autel.
Because consumer-level quadcopter drones are becoming more and more familiar to the general public, they think that drone is another term for a quadcopter. They do not realise a vast history and array of different remotely piloted vehicles classified as drones.
Examples of quadcopters
Examples of quadcopters are racing drones, photography drones, and agricultural drones.
The characteristics of these aerial vehicles are that they all have four propellers and motors on four arms to keep them in the air.
Flying a racing drone is an incredibly exhilarating experience. It requires a lot of skill, and the learning curve is so steep that you will destroy many drones in the process.
Drone racing is incredibly serious and competitive, but you can also capture incredible footage. There are many YouTube channels dedicated to drone racing, and one of the best pilots I have seen is Mr Steele:
You will notice the drone has four propellers and four motors attached to the body or frame via four arms. These features are what make this drone a quadcopter.
The particular orientation of the propellers on a quadcopter provides a very stable platform to take aerial photos and videos.
The propellers are situated far enough from the drone’s body to provide a large lever advantage. This lever advantage means that even the smallest increase in power to 1 of the motors can overcome stability issues caused by wind or other environmental factors.
I have always been amazed at how well my relatively tiny drone performs in moderately high winds.
If you want more power for your drone, you can easily lift 76 kg of a payload by increasing the number of propellers.
Once you add more than four propellers to a drone, it no longer is a quadcopter, and the type of “copter” it becomes is determined by the number of propellers it has.
A Hexacopter has six propellers on six arms from the drone’s body.
Adding more propellers means that the drone can lift much more weight as the effort is distributed across many more motors.
Hexacopters tend to be a lot more expensive than a quadcopter because of their increased size and extra parts required.
The benefits include:
- longer flight times because they can carry a much heavier battery
- have more power for lifting heavier payloads
- can carry much heavier and professional-grade cameras
The DJI Agras T30 is an example of a hexacopter flagship drone that can benefit farmers who want to automate their crop care.
The drone can operate over 40 ac/h and take off with a maximum weight of 76.5 kg. That amount of weight is an incredible amount of weight for a relatively small drone.
An octocopter is a drone with eight propellers and motors.
They can carry even more weight than a hexacopter, and our super-powerful drones can achieve a very high elevation. They can support very heavy camera equipment and offer much better safety and stability over other types of drones.
The downsides are massive drones and have much lower battery life when lifting heavy objects.
Adding any more than eight propellers around a drone frame is difficult as each propeller needs to operate without influencing the aerodynamics of the adjacent propeller.
As drones get bigger and the battery capacity increases, we may start seeing commercially available drones with even more than eight propellers.
The final word
This article covered the differences and similarities between a quadcopter and a drone.
Some people use the terms interchangeably, but a real definition can delineate the difference between a drone and a quadcopter.