What is a Drone
A ‘drone’ can be broadly described as any autonomous or remotely controlled robot, and although today’s drone-mania is mostly around the aerial “species”, the term applies equally to autonomous or remote vehicles that travel on land or underwater. For the purposes of this article, due to their high popularity, we will focus on aerial drones.
Aerial drones vary widely in architecture, size and material composition depending on their purpose and price-point. Most commercial drones are VTOL (Vertical Take-Off and Landing) types, which employ Multi- or Single-Rotor propulsion. As the name suggests, they are able to take off and land vertically, removing the need for a runway. The technology also allows them to hover in place which is highly beneficial in surveillance and photography applications. They are currently the most popular type of aerial drone, but other types like the Fixed-Wing or Fixed-Wing Hybrid are also used for specific purposes.
All aerial drones share the characteristic of having automated and remote flight control capabilities via programmable flight plans that work in conjunction with onboard technologies to keep the drone on the correct path and flying steady. The list of these technologies is both long and complex, but at the same time essential to understanding what an aerial drone is and the potential scope of what it can do.
Drone photography has enabled amateur photographers and studios to compete with established market players (P2)
Technologies incorporated in Aerial Drones
Aerial Drones use some of the most sophisticated technology available commercially. Broadly these technologies can be grouped into; Flight assistance, remote control, and data capture technologies.
Flight Assistance Technologies
Gyro Stabilization, IMU and Flight Controllers - Gyro Stabilization technology provides essential navigational information to the central flight controller of a drone, enabling instantaneous adjustments to compensate for the constantly varying natural forces moving around it, which gives drones their smooth flight capabilities.
The Central Flight Controller is considered the ‘brain’ of any drone, and an essential component of any flight controller is the IMU or Inertial Measurement Unit which detects changes in rotational attributes such as pitch, roll and yaw using one or more gyroscopes, as well as detecting the current rate of acceleration using one or more accelerometers.
Pitch refers to up or down angle of the nose of a drone, roll refers to the difference in angle from the horizontal which the left or right wing tip is and yaw refers to left or right angle which the nose of the drone is pointing which allows the drone to strafe left or right.
Obstacle Detection And Collision Avoidance Technology - Most drones employ a collision avoidance system which works by feeding 3D terrain data captured by the drones’ vision systems to the flight control system, which uses this information to identify and avoid obstacles.
GPS and Radar Positioning - When a drone is flight-ready, the on-board radar system will indicate that sufficient satellites from the GNSS (Global Navigation Satellite System) have triangulated the drone and that it is ready to fly. This information is used to guide the drone in its flight paths.
Internal Compass and Failsafe Return Home Function - The ‘Home Point’ or ‘Failsafe Function’ is a system that automatically guides the drone to return to a set location. To set this function the user must first calibrate the drones compass so it knows how and where to fly to safety. Modern drones have 3 modes where the Return to Home function is engaged; pilot initiated, low battery level, and loss of signal from the drones remote control.
UAV Remote Control System
Commercially available drones communicate over the 2.4GHz and 5.8GHz radio bandwidths. The latest drones have an effective control range of up to 7km (4.3 miles). And accessories like range extenders can extend this further. This range however can be drastically reduced by the topology of the land as well as surrounding skyscrapers, electrical signals and metal structures.
Cameras - The latest drones include cameras which can shoot film in 4k video as well as 12+ megapixel stills. These cameras are specifically designed for aerial film and photography utilizing integrated gimbals as well as optical and digital zoom. Gyro-stabilized gimbal technology allows the drone to capture quality aerial photos, film or 3D imagery by reducing shake and vibration effects of the drones flight on the camera.
Modeling, Mapping and Time of Flight Sensor - Higher end drones today utilize cutting edge technologies such as Multispectral cameras, Lidar, Photogrammetry, low light night vision and Thermal vision sensors which are used to compile precision data for a number of industries including; agriculture, real estate, and construction. For in depth assessment and reporting purposes.
In 2016, drones using Time-of-Flight sensors came on the market. ToF sensors can be used on their own or in conjunction with the above sensors to provide various solutions across many sectors. For example, ToF depth ranging camera sensors can be used for object scanning, indoor navigation, obstacle avoidance, and gesture controls for a more interactive drone experience.
Drones which can carry significant payloads are set to change “last mile” logistics globally (P3)
Drone technology has outgrown its niche hobbyist market and become a technology set to revolutionize industries in the coming future. From cinematography to crisis response and assessment, and logistics to Sports (drone racing is now a recognized and growing competitive sport in several countries), many aspects of our modern world are set to change irrevocably. In our next article we look at the industries drones are starting impacting here in Sri Lanka.