The past couple of posts we’ve talked about what we call drones, and some of the worries about drones but this week we’re going to give a fairly non-technical look at how drones work. Getting an idea of how something works gives you a leg up on understanding how it can be used most effectively in the civilian and commercial worlds. To do this, we’re going to reverse engineer and work backwards.
Drone propellers and motors
The thing(s) that keep the drones in the air are the propellers/rotors (thought technically rotors flex to help control the vehicle, drone propellers don’t flex. That doesn’t stop people from calling them rotors!). They spin at various speeds to help the drone hover as well as move all different directions. If we’re talking about a quadrocopter with four propellers (props), the front two propellers can slow down while the rear two speed up, causing the drone to lean forward and begin to move in that direction. Various other combinations allow the drone to slide to the left or fight as well as turn side to side.
The propellers are attached to the motors which provide the physical movement for the props. They transfer the electrical energy they receive into motion. The huge majority of motors you’ll see on any modern drone are electrical motors and they have various “kV” ratings, that is, number of rotations per volt. An average motor speed is in the 800-1100 kV rating, but they go much lower and much higher, to be sure.
Each of the motors are attached to Electronic Speed Controllers (ESC’s) which govern the amount of electricity reaches the motors. The more electricity, the faster the motor spins, the more force the prop creates. The “orders” for each ESC come from the Flight Controller, which essentially serves as the brains of the drone. The Flight Controller takes any commands it’s given and translates that into the technical details for each ESC. The flight controller also provides the computation necessary to keep the craft level when it’s not receiving any input as well as incorporate the GPS data (if there is a GPS attached) to keep the craft located where it’s supposed to be located. Some flight controllers are even able to steer the craft 100% autonomously, based on a waypoint map a pilot creates perhaps, though technology is advancing where drones are able to see objects in front of them and avoid them (‘detect and avoid’).
Drone transmitters and batteries
The final two major parts of the equation on the drone are the remote control receiver and the battery. The receiver listens for the commands from the transmitter which the pilot has in their hands. They use the transmitter to fly the craft as well as interact with various additional items on the drone…cameras, sensors, etc. The receiver hears those commands (most of the time!) and tells the flight controller, and the flight controller acts accordingly. The battery supplies continuous DC power to the drone, powering all the electronics on board and essentially serving as the gas tank. As the battery drains, the flight life of the drone follows. If the pilot doesn’t pay attention to his battery, he risks his drone falling out of the sky once there’s not enough energy left to spin the motors fast enough.
In another post we’ll talk about some of the additional systems that a person can attach to a drone (cameras with transmitters to send video back tothe pilot, sensors that can measure data through a variety of means, even small arms that can carry supplies and release them on command to people in need below) to make it more resourceful, but these are the basic essentaily you need to get a drone in the air and keep it there! As always, if you see a drone owner out in the wild and have questions, we love to talk about our drones and would love for your to stop by!