So you’ve recently gotten a new drone or perhaps are thinking about getting one.
Either way, it is a great idea to understand how they fly and, more importantly, how they are controlled. Comprehending the forces at work in getting your drone airborne is a worthwhile endeavor for any drone operator – regardless of your skill.
Here’s a list of what we will discuss in learning how drones are controlled. A basic overview will provide a solid background that will serve you well as a new (or advanced) drone operator:
- Basis of flight for aircraft
- Helicopter flight
- Drone flight
- Drones moving in 3-dimensions
- Radio frequency
- Wi-Fi control
Basis of flight for aircraft
Since we begin with an object that weighs far more than air, we must generate some force to get launched. Such a force is called lift, and it will push that object upward. This is the result of modifying air pressure below and above an aircraft.
A jetliner generates lift as it moves air below and above its wings. This air movement is initially generated from moving across the ground horizontally. The bigger that jetliner, the longer its runway will have to be to create the lift needed to get it airborne.
Once in flight, the jetliner only needs to maintain its horizontal momentum to sustain the proper amount of air moving over and beneath its wings. And it will moves solely in the direction that its nose is pointing.
When it comes to helicopters, directional control is dictated by changing which way the propellers are leaning – or altering the propeller blades’ pitch. In helicopter speak, that is referred to as “changing the attack of the propellers.”
For the most part, helicopters generally have one main propeller rotor, although some models have multi-rotors.
This brings us to the drone family – which is basically a helicopter. The drone models we see on the market today have multi-rotors. A drone can have as few as three propellers (which is rare) and as many as eight propellers.
These multi-rotors play an essential role in maintaining the stability of the drone as it flies. This is accomplished by changing the speeds of each of its propellers.
Like the helicopter, the directional control of a drone depends on the attack of its propellers. However, the attack change is achieved by slowing down some of the rotors to change their angle.
Drones moving in 3-dimensions
To move with precision within three dimensions, drones depend on two rather advanced sensors. These sensors determine the direction and play a massive role in keeping the unit stable and steady while in flight.
Accelerometer: This is what detects the drone’s linear movement as it moves in a straight line. It views the world in terms of the ED axes of space: X, Y, and Z.
An accelerometer will detect and measure any movement only along those axes. It does not register anything but a linear movement.
Gyroscope: This sensor is what detects any rotational movement. That includes moving around a line relative to the axes of 3D space.
Together the gyroscope and the accelerometer detect and measures all motion along the axes of 3D space.
Controlling a drone remotely means that there must be a wireless connection of some kind. This is done by using radio waves. And specific radio waves are defined by their unique frequency measured in hertz (Hz).
For transmitters and receivers to communicate using these invisible radio waves, they must be on the same frequency. This is how we can remotely control our drones.
In essence, a radio frequency is simply a way to communicate. In the world today, billions of devices are communicating wirelessly every day. As you may already be thinking, what prevents someone from taking control of my drone?
This is why your drone and device must be finely tuned to speak to one another. Such situations are avoided by the use of a unique identification code to identify transmissions.
More specifically, receivers and transmitters and receivers become paired using a “radio frequency identification,” or RFID. All data transmitted over a particular radio frequency is prefixed with this unique RFID so that receivers know that the information is legitimate.
As a general rule, low frequencies have greater ranges than high frequencies. This means that the higher frequency radio signals can only be used by local sources – since they are the only sources within range.
There was a time once when Wi-Fi was available only for use with a computer. However, as the technology became more advanced, it also became more compact and more intelligent.
This is why we are now seeing it bet integrated into smartphones, tablets, and other devices. In other words, Wi-Fi has become portable and remotely accessible.
This is why the majority of drones on the market today are Wi-Fi enabled. And it also allows drone operators to do lots of neat things with their drones.
For instance, they can broadcast live video to their computers, tablets, or smartphones. By using a mobile application, drones can even be controlled with a smartphone or tablet.
While it’s easy to see the benefits of using Wi-Fi for controlling your drone, there is a small setback. Wi-Fi operates on an ultra-high radio frequency, and as we already know, this limits their range of control – which would be around 600 meters.
Another technology that drones can use is Global positioning technology (GPS). Like Wi-Fi, it has also gotten more advanced and compact in the past few years.
GPS provides a lot of strategic flexibility. While it is mainly used to transmit location data back to a mobile app, it can also be used for pre-programming flight routes. An experienced drone pilot can program an elaborate drone flight plan – complete with waypoints.
Once it is programmed, a drone will obediently fly the prescribed path in the proper sequence. However, such a task depends on a reliable connection between the drone and the satellite signals it needs to navigate. And its instrumentation needs to be precise and recently calibrated.