Contributed by Amit Lal
A drone may look like a complex flying machine but like any other complex unit it is also composed of many smaller and simpler basic units referred to as various components of a drone. These components can be classified into two categories Essential Components: These are the components without which the drone would not be complete and would not be able to provide the basic necessary functionality. Non Essential Components: These are the components which may be skipped while the construction of a drone. These are the components that provide drones with additional capabilities. The Essential Components are listed below: Frame : Frames made up of various materials are present out there like Plastic, Glass Fiber and Carbon Fiber. The type of frame to choose depends upon the application of the quadcopter. The first thing on your mind should be the materials when picking the best frame. The materials play a significant role in determining the drone’s stability and efficient performance. Note that vibration is increasingly a nuisance in many drones, and if not managed well, it could lead to poor quality aerial images and possible damage to the electronic components. Most frame uses carbon fibers because of their lightweight properties. However, the downside of carbon fibers is radio signal interference. It is nonetheless a good material for your frame. To solve this, you must make sure that the radio and the antenna are connected effectively. The other commonly used materials include the aluminium and fiberglass. Aluminium, on the other hand, it’s a heavier metal to use on the frames, but it needs powerful motors. Although aluminium is more powerful and strong, it has a problem of an inevitable vibration.
Motors : The brushless motor is the next important component of the quadcopter. Motors should be powerful enough to allow flying.The motor speed rated in KV. The RPM of the motor varies with the KV rating and its input voltage. Mostly, the lower KV rating motors provide high thrust and higher KV rating motors provide low thrust For example, 2200kv rating motors can rotate with the RPM of 22000 if the battery voltage is 10V. Apart from the thrust, another aspect to the motor performance is how much current the motor draws from the battery. Remember to check the specs of your motors for their maximum amp draw, and ensure that your ESC’s are rated to withstand this amperage.
Electronic Speed Controller: An ESC is an electronic circuit which is used to change the speed and direction of brushless motor. Basically, an ESC converts DC battery power into 3-phase AC for driving brushless motors. It is the interface between the Motors and Flight Controller. While the selection of ESC, the current rating must be higher than the ampere drawn by all motors and other components. Normally an ESC has 5 inputs but these days an ESC comes with 4 input terminals, where 2 inputs terminals are for Ground and PWM signals coming from the Flight controller and other 2 are for battery input supply, these 2 inputs carry the high current to the ESC to supply the motor. ESCs also come with a battery eliminator circuit (BEC), which delivers the electric power to other circuitry without the need for multiple batteries. Electronic Speed Controllers offer high power, high frequency, high- resolution 3-phase AC power to the motors to make it fly.
Propellers: The propeller acts as wings of the flight. It pulls the air downwards and makes your drone fly. Almost, in every size, there are different types of propellers are available. Propellers largely affect the quadcopters flying speed, it’s load and the speed at which they can manoeuver. According to these attributes, you can decide the length and pitch of the propellers. The pitch is the shape and slant of the propeller. Longer size propellers provide stronger lift at lower RPM but it takes time to speed up and slowdown. Shorter size propellers quickly change the speed of quadcopter and produce better manoeuvering capabilities. As compare to longer propellers, it requires more energy/current to spin. This causes excess strain on the motors, which may lead to a shorter life span for the motors.
Flight Controller : The flight controller is the brain of the Quadcopter. This is a small computer board with various sensors which understand the movement of the craft. It has sensors like Gyroscope, Accelerometer, Barometer and Magnetometer. According to the signal coming from the transceiver , it controls the motors and craft. Flight controllers configured with computer software. It uses computer software like Cleanflight, Betaflight, Mission planner etc. Selecting the flight controller is just a personal choice in many ways. As per your quadcopter requirements, you can choose the affordable, reliable flight controllers which work with most components easily.
Transmitter and Receiver :
Radio Transmitter is an electronic device that uses radio signals to transmit commands wirelessly via a set radio frequency over to the Radio Receiver, which is connected to flight controller of quadcopter being remotely controlled. Radio transmitters and receivers manipulate electricity resulting in the transmission of useful information through the atmosphere or space. The transmitter sends a signal over a frequency to the receiver. The transmitter has a power source, that provides the power for the controls and transmission of the signal. Simply, it is a Remote Controller which use to control altitude, speed, the orientation of the drone. Radios are usually come paired with their compatible receiver. There are a variety of RC transmitters available in the market. You can choose one of them which matches your specification.
Battery : Finally to power on your quadcopter, you need Lithium polymer (LIPO) battery. Flight time of your quadcopter depends on the battery capacity. Generally, the LIPO batteries are rating with its capacity in mah, thenumber of cells in series (like 3S, 4S ) and it’s C rating (30C/40C). The battery is the single heaviest component of your drone, just because using bigger size battery doesn’t mean it will fly longer. So you need to choose the battery according to its size, capacity, C rating, its voltage etc. To more deeply about the choosing of appropriate LIPo battery for your drone, visit the below tutorial.
The Non Essential Components are listed below Global Positioning System : Waypoint GPS Navigation allows a drone to fly on its own with it's flying destination or points preplanned and configured into the drone remote control navigational software. This instructs the drone where to fly; at what height; the speed to fly at and it can also be configured to hover at each waypoint. Drones typically orient themselves using GPS, which helps keep them stable while in flight, allowing pilots to hover and to make sure they don't fly into random places.
The compass allows the drone to know its heading or direction in space. If the compass has not been calibrated, the GPS will not allow the drone to initiate a mission. The compass has an internal magnetometer that can be affected by things like reinforced concrete, buildings, and antennas.
Compass calibration on a drone is done to align the drones' flight system with the Earth's magnetic north, not its true north. ... An algorithm stored in the rom memory of the aircraft accounts for this delta and allows for proper calibration of the magnetometer, the drone's electronic compass.
Telemetry is used to retrieve flight information of your drone on your computer or your radiocontrol in order to follow several parameters of your aircraft on the ground.
The Telemetry API is a gRPC stream to which drones can push their position and health information. Telemetry allows for realtime information and communication in the form of a data stream. It enables applications to have a live icon of a moving drone displayed on a map.
The FPV camera is mounted onto a drone to send real time video down to the ground using a video transmitter. The FPV camera allows you to see where the drone is flying and what it is seeing as if it had its own eyes. Military drones or large high-end drones can fly thousands of miles using FPV technology.
A video camera is mounted on the unmanned aerial vehicle and this camera broadcasts the live video to the pilot on the ground. ... Depending on the drone, the receiver of the live video signals can be either the remote control unit, a computer, tablet or smartphone device.
Gimbals are used to stabilise camera payloads that have been mounted on drones and other autonomous vehicles such as UGVs. The gimbal integrates an IMU (Inertial Measurement Unit) that responds to motion and provides inputs to a controller that activates separate motors to keep the payload steady on each axis.
So these are the various components that are generally used in the construction of drones. Apart from these there are other components but they have very specific use and are only used in specific cases.