SkillRary

A drone, in a technological context, is an unmanned aircraft. Drones are more formally known as unmanned aerial vehicles (UAVs) or unmanned aircraft systems (UASes). Essentially, a drone is a flying robot.

The aircraft may be remotely controlled or can fly autonomously through software-controlled flight plans in their embedded systems working in conjunction with onboard sensors and GPS.

In the recent past, UAVs were most often associated with the military, where they were used initially for anti-aircraft target practice, intelligence gathering and then, more controversially, as weapons platforms.

Drones are now also used in a wide range of civilian roles ranging from search and rescue, surveillance, traffic monitoring, weather monitoring and firefighting to personal drones and business drone-based photography, as well as videography, agriculture and even delivery services.

Origin of a drone can be traced with special techniques to provide relevant information to the military. The very first aircraft with reusable type radio control mechanism was designed in the 30s and it worked like a base model for all new advancements of today’s world.

Later, the military drones were developed with classic sensors and camera units and now they have been fixed inside missiles too. With so much advancement in technology, now you can easily find so many variants of drones. Few are used for military applications but others are finding the potential role in many big companies.

As per a recent new update, Google and Amazon are developing their drones so that parcels can be delivered by air with ease. One more interesting concept is presented by Facebook as they are thinking to develop some giant drones that can carry the signal to remote locations for direct internet access.

Drones in today’s world have also been an important part of the film industry and news reporters are also using them to carry information from inaccessible locations.

A typical unmanned aircraft is made of light composite materials to reduce weight and increase manoeuvrability. This composite material strength allows military drones to cruise at extremely high altitudes.

UAV drones are equipped with a different state of the art technology such as infrared cameras, GPS and laser (consumer, commercial and military UAV). Drones are controlled by remote ground control systems (GSC) and also referred to as a ground cockpit.

An unmanned aerial vehicle system has two parts, the drone itself and the control system.

The nose of the unmanned aerial vehicle is where all the sensors and navigational systems are present. The rest of the body is full of drone technology systems since there is no space required to accommodate humans.

The engineering materials used to build the drone are highly complex composites designed to absorb vibration, which decrease the sound produced. These materials are very lightweight.

Drone Types And Sizes

UAV drones come in a wide variety of sizes, with the largest being mostly used for military purposes such as the Predator drone. The next in size is unmanned aircraft, which have fixed wings and require short runways.  These are generally used to cover large sections of land, working in areas such as geographical surveying or to combat wildlife poaching.

VTOL Drones

Next in size for drones are what is known as VTOL drones.  These are generally quadcopters but not all. VTOL drones can take off, fly, hover and land vertically. The exact meaning of VTOL is “Vertical Take-Off and Landing”.

Quite a few of the latest small UAV drones such as the DJI Mavic Air 2 take VTOL to the next level and can be launched from the palm of your hand.

Radar Positioning & Return Home

The latest drones have dual Global Navigational Satellite Systems (GNSS) such as GPS and GLONASS.

Drones can fly in both GNSS and non-satellite modes.  For example, DJI drones can fly in P-Mode (GPS & GLONASS) or ATTI mode, which doesn’t use GPS. Highly accurate drone navigation is very important when flying, especially in drone applications such as creating 3D maps, surveying landscape and SAR (Search & Rescue) missions.

When the quadcopter is first switched on, it searches and detects GNSS satellites. High-end GNSS systems use Satellite Constellation technology. A satellite constellation is a group of satellites working together giving coordinated coverage and are synchronized so that they overlap well in coverage. Pass or coverage is the period in which a satellite is visible above the local horizon.

UAV Drone GNSS On Ground Station Remote Controller. The radar technology will signal the following on the remote controller display;

• The signal that is enough drone GNSS satellites have been detected and the drone is ready to fly
• Display the current position and location  of the drone in relation to the pilot
• Record the home point for ‘Return To Home’ safety feature

Most of the latest UAVs have 3 types of Return to Home drone technology as follows;

• The pilot initiated a return to home by pressing a button on Remote Controller or in an app
• A low battery level, where the UAV will fly automatically back to the home point
• Loss of contact between the UAV and Remote Controller, with the UAV flying back automatically to its home point

The latest high tech drones are now equipped with collision avoidance systems. These use obstacle detection sensors to scan the surroundings, while software algorithms and SLAM technology produce the images into 3D maps allowing the drone to sense and avoid.  These systems fuse one or more of the following sensors to sense and avoid;

• Vision Sensor
• Ultrasonic
• Infrared
• Lidar
• Time of Flight (ToF)
• Monocular Vision

Gyroscope Stabilization, IMU And Flight Controllers

Gyro stabilization technology gives the UAV drone its smooth flight capabilities. The gyroscope works almost instantly to the forces moving against the drone, keeping it flying or hovering very smoothly. The gyroscope provides essential navigational information to the central flight 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 includes 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 drones flight controller. The flight controller is the central brain of the drone.

Here is a terrific article, which covers gyro stabilization and IMU technology in drones.

UAV Drone Propulsion Technology

The propulsion system (motors, electronic speed controllers and propellers) are the drone technology, which moves the UAV into the air and to fly in any direction or hover.  On a quadcopter, the motors and propellers work in pairs with 2 motors/propellers rotating clockwise (CW Propellers) and 2 motors rotating Counter Clockwise (CCW Propellers).

They receive data from the flight controller and the electronic speed controllers (ESC) on the drone motor direction to either fly or hover.

Top UAV drone motors and propulsion systems are highly advanced and include the following components;

• Motor Stator
• Motor Bell (rotor)
• Windings
• Bearings
• Cooling System
• Electronic Speed Controllers
• ESC Updater
• Propellers
• Wiring
• Arm