Researchers in Germany have demonstrated a new vision-assisted automatic landing system which could support autonomous aircraft in the future.
Researchers in Germany have demonstrated a new vision-assisted automatic landing system which could support autonomous aircraft in the future.
Automatic landings have long been standard procedure for commercial aircraft. While major airports have the infrastructure necessary to ensure the safe navigation of the aircraft, this is usually not the case at smaller airports.
Researchers Technical University of Munich (TUM) and TU Braunschweig have now demonstrated a completely automatic landing with vision-assisted navigation that functions without the need for ground-based systems.
Future aviation
At large airports, the Instrument Landing System (ILS) makes it possible for commercial aircraft to land automatically with precision. Antennas send radio signals to the autopilot to make sure it navigates to the runway safely. Procedures are also currently being developed that will allow automatic landing based on satellite navigation. Here too a ground-based augmentation system is required.
However, systems like these are not available for general aviation at smaller airports, which is a problem in case of poor visibility – then aircraft simply cannot fly.
“Automatic landing is essential, especially in the context of the future role of aviation,” says Martin Kügler, research associate at the TUM Chair of Flight System Dynamics.
“This applies for example when automated aircraft transport freight and of course when passengers use automated flying taxis,” he added.
Camera-based optical reference system
In the C2Land project, supported by the German federal government, the autopilot uses GPS signals to navigate. However, GPS signals are susceptible to measurement inaccuracies due to issues such as weather. GPS approach procedures require the pilot to take over control at an altitude of no less than 60 metres and land the aircraft manually.
In order to make completely automated landings possible, the TU Braunschweig team designed an optical reference system, including a camera in the normal visible range and an infrared camera that can also provide data under conditions with poor visibility. The researchers also developed custom-tailored image processing software that lets the system determine where the aircraft is relative to the runway based on the camera data it receives.
The TUM team developed the entire automatic control system of TUM’s own research aircraft, a modified Diamond DA42.
The aircraft is equipped with a Fly-by-Wire system enabling control via an advanced autopilot, also developed by the TUM researchers.
In order to make automatic landings possible, additional functions were integrated into the software, such as comparison of data from the cameras with GPS signals and calculation of a virtual glide path for the landing approach, as well as flight control for various phases of the approach.
Landing
In late May the research aircraft made a completely automatic landing at the Diamond Aircraft airfield.
Test pilot Thomas Wimmer said: “The cameras already recognise the runway at a great distance from the airport. The system then guides the aircraft through the landing approach on a completely automatic basis and lands it precisely on the runway’s centreline.”
