Unmanned aerial vehicles (UAVs) are vehicles that do not have a pilot on board. They can be remote-controlled or fly autonomously based on complex dynamic automation systems.
Advancements in software development, computer technology, global navigation, lightweight materials, sophisticated sensors, advanced data links and component miniaturization contribute to the extensive interest in using unmanned aerial systems (UASs) in civilian roles.
Since UASs are being used extensively in military operations, the non-military applications are also being considered. Recently, the military demonstrated how it was possible to use UASs as communication platforms for the bridging of rugged terrain.
It is possible for disaster recovery officials to use UASs for establishing and maintaining communications when the infrastructure is overloaded or disabled.
An official with the International Association of Chiefs of Police anticipates that in the near future police and fire fighting units can have hand-deployed small UASs for assisting at wildfire locations and crime scenes.
Image Credit: Photos.com
Common types of UAS include:
- Target and decoy – offering ground and aerial gunnery a target that simulates an enemy aircraft or missile.
- Reconnaissance - providing battlefield intelligence.
- Combat - enabling attack capability for high-risk missions.
- Research and development – for further developing UAV technologies to be combined into field deployed UAV aircraft.
- Civil and commercial UAVs – These UAVs are specifically designed for civil and commercial applications.
Design of UAS Technology
UAS comprise several elements or sub-systems along with the aircraft. Certain design criteria to be considered while constructing the UAV includes:
- Air Vehicle – Payload: The key determinant of the size, layout and all-up-mass of the aircraft is the mass and size of the payload and its need for electrical power supplies. The payload may range from 1 to 1000 kg especially for armed air vehicles. The layout and configuration of the airframe also depends on the required position of the payload. Imaging payloads for surveillance vehicles need a full hemispherical field of view and a large surface area for the antennae.
- Air Vehicle – Endurance: The flight endurance required of an air vehicle may range from 1 hour for a close-range surveillance vehicle to over 24 hours for an airborne early warning system or a long-range surveillance vehicle. The mass and volume of the fuel load to be carried will be a function of the endurance and reciprocal of the efficiency of the aerodynamics of the aircraft and its power unit.
- Air Vehicle – Radius of Action: The aircraft’s radius of action depends on the efficiency of its use, the amount of fuel it can carry, its speed, frequency and sophistication of its communication links. The data rate requirements and other aircraft functions will impact the frequency range and electrical power required for the radio links.
Operating UAS Technology
It is important that operators know on demand where an aircraft is at a particular point of time. It is also essential for the aircraft to know where it is if autonomous flight is needed at any time during the flight.
For a completely autonomous operation without any communication between the air vehicle and the control station, it is important to carry sufficient navigation equipment in the aircraft.
In the past, inertial navigation systems or less sophisticated INS was needed, but presently a global positioning system or a GPS acquires positional information from an array of earth satellites. Differential GPS technology may also be used.
For non-autonomous operation wherein communication between the control station (CS) and aircraft is continuous or where there is a risk of blocking of the GPS system several techniques are adopted:
- In radar tracking, the aircraft is fixed with a transponder that responds to a radar scanner emitting from the CS so that the position of the aircraft is seen on the CS radar display in range and bearing.
- In radio tracking, the radio signal from the aircraft is tracked and its range is determined from the time taken for a coded signal to travel between the aircraft and the CS.
- In direct reckoning, the computer integration of time elapsed and velocity vectors helps determine the aircraft position.
Advantages of UAS Operation
The advantages of UAS technology are:
- This system does not require a qualified pilot to be on board.
- They can enter environments that are dangerous to human life.
- UAS operation reduce the risk of exposure of the aircraft operator.
- UAS can remain in the air for up to 30 hours performing an accurate, repetitive raster scan of a region day and night in fog or complete darkness under computer control.
- Geological surveys can be performed using this technology.
- UAS technology can perform thermal or visual imaging of a region.
- UAS technology can measure radio, cell phone or TV coverage over any terrain.
Products –Latest Advancements
Fulmar System from Aerovision
The Fulmar aerial tele-detection system from Aerovision includes a self-piloted small size UAV with capabilities to capture and transmit real time infrared or video images, a ground control station, a launcher and a recovering net.
The Fulmar features high lift-drag ratio and excellent stability and also long endurance due to its low consumption. It has excellent aerodynamic efficiency that enables a wide range of climb rates and speeds. The aircraft can land on water on a pneumatic skid.
The Fulmar system can be operated easily as its flight, take-off and landing are automatic and can be programmed using GPS-3D way-points in the ground control station. The station also helps direct the movements and zoom of the onboard camera that is geo-referenced and gyro-stabilized.
ScoutTM Micro-UAV from Aeryon
Small unmanned aerial systems offer public safety and military users with superior quality aerial intelligence directly controlled by ground personnel. It is possible to deploy the Scout™ micro-UAV from Aeryon with minimal training and in extreme environments.
For a number of commercial applications, collecting aerial imagery from the Aeryon Scout™ micro-UAV is quicker, more precise and more economic when compared to manned aircraft, satellites or ground-based alternatives.
Nova Block III from Altavian
The Nova Block III from Altavian offers both real time infrared thermal and HD data as well as enables precision 3D mapping. The Nova Block III can collect high-resolution data and offer real-time results with speed and accuracy.
The features of the Nova Block III are:
- Can be hand-launched
- Has a lightweight design
- Minimal launch time
- Suitable for all-terrain and water landings
- Good range even beyond line of sight
- Has a modular payload for a range of sensor add-ons
- Customized features to suit specific applications.
AD 150 UAS from American Dynamics
The AD-150 UAS from American Dynamics is a vertical take-off and landing (VTOL) UAS. The AD-150 can perform vertical landings and take-offs and cruise at high speeds making it ideal for sea and land operations.
The AD-150 features a modular mission payload design with external stores and internal bays present in the center of gravity of the vehicle. The versatile payload bay configuration of the AD-150 enables it to support highly demanding payload missions and systems.
American Dynamics Flight Systems AD-150 VTOL UAV
Video animation of the AD-150 UAS performing a vertical take-off and landing. Video Courtesy of American Dynamics
Sky X from Alenia Aermacchi
The Sky-X UCAV Technology Demonstrator from Alenia Aermacchi has been conceived to test technologies relevant to a broad range of civil security missions especially surveillance, reconnaissance and ground observation. The Sky-X technology demonstrator became the first advanced UAV in Europe to fly over the 1000 kg category.
Sources and Further Reading