What accessories are needed to build a quadcopter drone?
The world of drones is a very new one. It is not more than twenty years ago that we saw the first drones that were not military or made by hobbyists. The most commonly known drone-type is the multi-rotor drone, which is currently primarily used for filming or inspecting from the sky. A very important component of the modern drone is a flight controller.
Quadcopter drone kits typically include all the necessary components to build and assemble a functioning quadcopter drone. Some common components in a quadcopter drone kit are:
1. Drone Frame
The main body of the quadcopter mounts and fixes all drone accessories on the drone frame.
Four brushless motors are powered in conjunction with propellers to provide lift and maneuverability.
Four blades that spin to create lift and thrust.
An electronic speed control follows a speed reference signal (derived from a throttle lever, joystick, or other manual input) and varies the switching rate of a network of field effect transistors (FETs). By adjusting the duty cycle or switching frequency of the transistors, the speed of the motor is changed. The rapid switching of the current flowing through the motor is what causes the motor itself to emit its characteristic high-pitched whine, especially noticeable at lower speeds.
Different types of speed controls are required for brushed DC motors and brushless DC motors. A brushed motor can have its speed controlled by varying the voltage on its armature. (Industrially, motors with electromagnet field windings instead of permanent magnets can also have their speed controlled by adjusting the strength of the motor field current.) A brushless motor requires a different operating principle. The speed of the motor is varied by adjusting the timing of pulses of current delivered to the several windings of the motor.
Physically, a flight controller is nothing more than a circuit board with electronic chips on them. You can compare them to the motherboard and processor in your laptop. The flight controller is the brain of a drone. A small box filled with intelligent electronics and software, which monitors and controls everything the drone does. And just like the brains of different organisms, flight controllers also vary in sizes and complexity.
The flight controller is connected to a set of sensors. These sensors give the flight controller information about like its height, orientation, and speed. Common sensors include an Inertial Measurement Unit (IMU) for determining the angular speed and acceleration, a barometer for the height, and distance sensors for detecting obstacles. Just like how we perceive as humans, the drone filters a lot of this information and fuses some to get more efficient and precise information. Advanced flight controllers can sense more precisely and detect differences more quickly.
Aside from sensing what’s going on, a flight controller… unsurprisingly controls the motion of the drone. The drone can rotate and accelerate by creating speed differences between each of its four motors. The flight controller uses the data gathered by the sensors to calculate the desired speed for each of the four motors. The flight controller sends this desired speed to the Electronic Speed Controllers (ESC’s), which translates this desired speed into a signal that the motors can understand.
Calculating the movements, fusing and filtering the sensory information, and estimating the safety and durability of a flight is all done by an algorithm. A fancy word that is used a lot nowadays which in essence nothing more than a set of strict rules that every microchip on the board has to apply to. The most commonly used flight control algorithm is called PID control: Proportional Integral Derivative control. Within this area, there is a lot of research going on, which resulted in INDI: Incremental Nonlinear Dynamic Inversion. This algorithm reads out and reacts to incoming information way faster, therefore making the drone flight more stable.
A key part of a flight controller is communication. A part of the sensor’s job is to give out information that needs to be translated clearly for a pilot to read, which means efficiently. An obvious thing to communicate is its battery level, which can decide if a pilot wants to fly further or return to the charge.
But communication goes further than from flight controller to human pilot; with the entrance of autopilot programs in the drone industry, flight controllers need to communicate with other computer systems about its flight destination and how to get there. Communication is mostly done with Wi-Fi and radio frequencies right now, but cellular solutions are also already in use.
What kind of flight controllers are there?
There are a lot of different flight controllers on the market. They range from very basic to expensive systems. To make it a bit more comprehensible, I made four categories based on their users.
- FC is for the hobbyist/builder – easy to install and perfect for those who don’t want to spend a lot of money to begin with.
- Racing FC – Designed to be extremely lightweight, precise and responsive. Most of them cost €50 or less.
- FC for filming – While most drones with a camera are included with purchase, these flight controllers are more focused on creating smooth footage and ease of control for the pilot. In this space, the Chinese company Dajiang Innovations (DJI) is a household name.
- Commercial FC – the latest market segment developed in previous years. These are for state-of-the-art drones, capable of flying and transporting high-value cargo safely. The biggest players in this space are DJI and Pixhawk, but newer flight controllers like Auterion’s Skynode and Fusion Engineering’s Fusion Reflex are also promising in the industry.
A rechargeable battery that provides power to the quadcopter.
A device used to control the quadcopter’s movements and features.
Some quadcopter kits may include a camera and gimbal for aerial photography or videography.
It’s important to note that building a quadcopter drone requires some technical knowledge and experience. If you’re new to building drones, it’s recommended to start with a beginner-friendly kit or seek assistance from a professional.
What accessories are needed to build a quadcopter drone