Drones

Drones are also known as Unmanned Aerial Vehicles (UAV). We classify drones into 3 major categories:

• Recreational

• Professional

• Military

Recreational and professional drones utilize similar basic technology which includes a lithium polymer battery for power, a camera mounted on a stabilized gimbal, and a radio communication system. Most also include a dedicated controller, though some less expensive consumer models can be controlled using only a smartphone or tablet.

Other key technologies include GPS for tracking the drone’s position, various sensors to help avoid unwanted collisions, and intelligent flight modes that can automatically focus on a point of interest or track a moving subject.

The Drone

At the core of any system is the aircraft, and most consumer and prosumer drones today are quadcopters. Today, all multi-rotor drone systems designed for photo and video use a fixed-pitch propeller system. Most models use removable propellers made from a plastic/fiberglass composite that have a simple twist locking system to hold the propeller in place. Alternatively, some will use a folding propeller system.

The drone's propellers are driven by brushless motors that spin at very high speed to produce the thrust required to fly. Each motor has a corresponding speed controller unit that allows for slight adjustments in the speed of the rotor. Varying the speed of the individual motors relative to one another, will allow pitch, yaw, roll and altitude.

Flight controller

The flight controller is your direct line of command to the drone, and the two are linked using a radio control system, typically at 2.4 or 5.8 GHz. Input from the sticks on the flight controller sends signals to the aircraft directing it to adjust the speed controllers on each motor. Additional inputs allow you to control the camera and other features specific to the model you’re flying.

The same radio signal used for command and control also allows the video signal to be fed from the drone to the controller’s screen, providing a real-time view for shooting photos or video. The controller can be a smartphone, iPad, or a dedicated controller that comes with the unit.

In addition to seeing a live video feed, the screen allows you to monitor telemetry from the aircraft and includes all the controls you would expect for photography such as custom WB, bracketing, shooting style, and other camera settings.

Gimbal

Most drones actually move quite a bit as they maneuver around or make corrections to maintain position. To compensate, the camera is mounted to a gimbal: a device that isolates it from the vibration and movement of the drone. Most gimbals use a 3-axis system that allows for yaw (rotational stabilization), pitch (holding the horizon during forward and backward movement), and roll (holding the horizon during side-to-side movement).

Gimbals use brushless motors that are very precise and hold the camera in place so that video and photos are in focus. Some systems also offer a dual operator mode that allows the pilot to fly, while a separate camera operator runs the gimbal.

GPS

All recreational and professional drones today rely on GPS technology, typically using both the Global Positioning System and GLONASS (the Russian GPS system).

GPS makes it surprisingly easy to hold, fly a straight line, or orbit a subject while the computer does the hard work of making small adjustments to compensate for wind direction and turbulence. However, GPS, like any technology, can fail. As a result, learning to fly a drone without GPS assistance is an important skill to learn.

Collision Avoidance Systems

A big advancement over the past couple years has been the development of collision avoidance systems that use vision, sonic and infrared sensors to avoid obstacles. Vision systems can ‘see’ objects and halt the aircraft before it strikes something, however they usually have a limited range (15m/50ft), and the sun can sometimes create issues by causing them to think something is in the way when nothing is there.

Sonic systems use sound (much like bats) to sense objects and are usually aimed at the ground and used for auto-landing operations and ‘positioning’ on the ground in lieu of GPS. IR (infrared) sensors are a relatively new option and work based on reflected IR spectrum light. These are short range and have issues in low light, but work in a similar fashion to vision systems for obstacle avoidance.

Batteries

Most drones use lithium polymer, or ‘LiPo’ batteries. These cells come in all sorts of shapes, sizes and power ratings. ‘Smart LiPo’ batteries have built-in charge/discharge regulators and sensors that can report battery voltage and temperature via an app or the press of a button. Typically, LiPo batteries run both the controller and the aircraft, and flight time usually ranges from approximately 15 to 30 minutes depending on your model, the conditions, and how aggressive you are at the controls.

Gyro stabilization technology

Gyro stabilization technology gives the UAV drone its smooth flight capabilities. The gyroscope works almost instantly to the forces moving against the drone. The gyro provides essential navigational information to the controller.

The inertial measurement unit (IMU) works by detecting the current rate of acceleration using one or more accelerometers. The IMU detects changes in rotational attributes like pitch, roll and yaw using one or more gyroscopes. Some IMU include a magnetometer to assist with calibration against orientation drift.

The Gyroscope is a component of the IMU and the IMU is an essential component of the drone’s flight controller. The flight controller is the central brain of the drones.