Science Fiction was Yesterday

German Air Traffic Control estimates the number of private drones in ­Germany at 500,000; the 2016 Christmas season alone witnessed the addition of 100,000 new systems. The rapid rise in the sale of drones increases the risk of collisions, crashes, and accidents. The obligation of drone owners to have ­proper insurance coverage has been in place since 2005. And now it is time for clear regulations to ensure air traffic safety beyond model airfields: in 2015, ­fourteen flying objects were sighted in close proximity to airplanes and helicopters, and in 2016 there were sixty reports. In January 2017, Minister ­Dobrindt ultimately introduced an interstate drone ordinance for Germany: the most important corner­stones relate to labelling ­requirements, drone licensing requirements, flight altitudes, and flight areas.

Drones are unmanned aerial vehicles (UAVs) that can be used privately or commercially. Private persons primarily use camera drones in the form of multicopters, which can be controversial: in addition to safety-relevant regulations, it is crucial to observe data privacy laws, especially because film and photography are not permitted everywhere. The laws change continually; therefore, regular updating of information is required.

Commercial use opens up entirely new application possibilities for drones; discussions in this direction presumably include parcel delivery via UAVs. Horror scenarios paint pictures of flying objects filling the sky. The application of UAVs in civil protection or disaster control is undisputed: fire-fighting and sea and mountain rescue missions can be coordinated more efficiently with UAVs. In the future, industrial facilities will also be able to be monitored by drones to detect gas leaks, for example. Feasibility studies are being carried out to test their use in production facilities.

Drones in Fire Department Operations
UAV systems are already used today in rescue missions. In the most straightforward fire department operations, they are used to localise the source of the fire; this is especially useful in forest fires when initiating targeted fire-fighting operations. The U.S.A. has already gained positive results in this respect.
These systems should also be used to save lives in accidents involving the transportation of hazardous materials. Drones aid in determining the condition of the injured or whether there are leaks, detecting hazardous materials, and measuring the concentration of the hazardous materials: With this data, dispersion forecasts of pollutant clouds can be deduced and appropriate preventive measures coordinated. The further development of these systems is the subject of the AirShield research project funded by the Federal Ministry of Education and Research.

Sensor Technology Challenges
UAVs used privately are only allowed to fly within direct sight of the operator and must be kept away from other flying objects. Professional drones, however, fly autonomously; therefore, high demands are placed on their safety systems. The UAVs must be able to determine their exact position at any time and react automatically to external influences. Sophisticated sensor technology is necessary for aircraft operations.

Safe Flying
Take-off and landing are particularly challenging at high-speed winds. It is necessary to quickly offset so-called gust effects and, thus, be able to determine the exact position to within a centimetre. Satellite navigation and reference measurements aid this procedure. The interaction between the flight calculator and the navigation and air-data sensors makes it possible to take effective countermeasures. RWTH Aachen proved this impressively.

DHL Paketkopter 3.0
In collaboration with the Institute of Flight System Dynamics (of RWTH Aachen), which is directed by Prof. Dieter ­Moormann, DHL Paket tested autonomous cross-country flights in the Bavarian village of Reit im Winkl at the beginning of 2016. Packages were successfully delivered from the valley to Winklmoos­alm across 8 km and ascending 500 metres in altitude at quickly-­changing weather conditions and high temperature fluctuations. Medicine was able to be expedited to the DHL Skyport in the mountains in just eight minutes; a car would have taken thirty minutes under winter conditions.

This flight was carried out without visual contact; therefore, redundant safety systems were applied and a data link set up with a long range: Radio communication and a mobile phone network made operation possible. Delivery was also carried out intelligently: Loading and unloading of the package was carried out automatically and the batteries were even changed to facilitate an immediate return flight. This flight proved the technical feasibility of such delivery methods. DHL was the first parcel service worldwide to test the extensive integration of package delivery via UAVs into the delivery chain (dpdhl.de/paketkopter).

In December 2016 other logistics companies followed suit: DPD and Amazon conducted flights in France and Cambridge, respectively. For daily application of UAVs, it will be necessary to establish the legal parametres of UAV flight and also continue to refine the drones.

Future Project: Autonomy and Swarming
In large-area disasters in the future, drones should be able to fly without active control in order to autonomously analyse a given area and forward the recorded data. Possible application scenarios include nuclear accidents or major earthquakes, in which streets are damaged or the telephone network fails, for example. This autonomous areal analysis is only possible in drone swarms in which the individual UAVs communicate with each other and forward their information and data to ground stations. The fact that drones in a swarm must not be allowed to cause collisions goes without saying.

Prevention of Collision via Distance Measurement
UAVs present a large risk to the cockpits and engines of rescue helicopters and low-flying passenger airplanes. To allow drones to avoid other aircrafts, distance sensors are integrated into autonomous UAVs; depending on the distance to be measured, radar systems or LiDAR systems could be used. LiDAR systems will probably also play a role in so-called near-field navigation near buildings (e.g., for inspection tasks) or even inside buildings.

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Dangers of Drones
We will soon see the commercial application of autonomous drones, in which the control pilot does not have visual contact with the UAVs during flight. Another challenge will be tracking enemy drones.

Thus, not only is intelligent automation the focus of development of these flight systems, but also simultaneous drone detection in order to ensure reliable drone defence.

Drone Defense
Multi-sensors are already being used to monitor the airspaces above prisons, government buildings, industrial facilities, and stadiums. If a dangerous drone is detected, there are a few conceivable defense techniques available. The possibility of taking over or destroying a UAV system via electromagnetic fields is currently the topic of research. Attacks via jammers or spoofers could force the drone to return to its starting position, leave its current path, land, or crash. Counter-drones with capture systems would not be practical because they would have to be very large and controlled in a targeted manner.

The Dutch police are developing an unusual method. They are currently training eagles to catch small drones in flight. You will find a video showing the eagles in action here:
https://www.youtube.com/watch?v=HifO-ebmE1s