Landing and recovery is an area of significant challenge for UAV operators in the defence sector. While fixed wing craft are preferred due to their light weight, long range, and cost effectiveness, recovering them through landing could be described as difficult at the best of times. For maritime operators, recovery is even more challenging, and there hasn’t been a robust solution for some time now.
It looks like that’s all about to change, with recent design innovations developed by defence contractor BMT, and the University of Bristol.
Machine Learning Algorithm Used to Create a Perched Landing Model
A quadcopter UAV has no trouble adjusting speed and orientation in mid-air. These helicopter-inspired drones can easily take off from a very small pad space, and can be recovered in a similarly small space. The quad design is used mostly on consumer and commercial drones, but is not suitable for all military applications.
To bring the easy recoverability benefits to a fixed wing design, engineers have taken the approach of a perched landing. Much like a bird would come to a graceful lift and stop to settle on the ground, a UAV can adopt similar principles to come to a safe landing in a targeted area, with minimal velocity. Not only does this make landings safer without risk of damage, but it can also make landings more accurate.
How did they do it? BMT Defence Services and the University of Bristol have developed a UAV that can adjust wing angle in mid-flight. Unlike fixed wing designs, the new innovation will have morphing wings that are controlled by electric motors within the main structure of the craft. Plenty of inspiration is taken from nature, but it is advanced computer technology that has allowed the UAV perched landing to become a reality.
By conducting multiple test runs, engineers were able to determine the ideal trajectory and wing angle to achieve a safe and controlled landing over a small surface area. Computers analysed each simulated landing to create case scenarios for various landing conditions, and a wind tunnel model was also used during the development.
The Idea is not a New One, but it Has Never Been Taken This Far
As far back as 2015, Dr W.J. Crowther from the University of Manchester wrote a NATO paper on Perched landing and Take Off for Fixed Wing UAVs. The paper stated that while UAV adoption has increased, there was no real solution to the problem of landing UAVs within urban areas or on unconventional runways. For a normal and safe UAV landing, the ground area tolerances are quite small, so Dr Crowther proposed that a perched landing could be used to create a steep conventional approach, with an extended flare landing attack where the UAV pitches up to gain height and reduce speed. At the peak of the attack angle, the craft would then quickly return to the ground, ideally without any damage.
The lightweight nature of fixed wing UAVs make the low damage landing a reality, and these most recent developments by BMT prove that the concept is transferrable to real world scenarios.
What Does This Mean for the Future of UAVs?
This is great news for military operators, and also for organisations involved in humanitarian relief. UAVs can be used to deliver documents or light payloads in situations where normal access is not possible, and the perched landing model will prevent damage to the drone, allowing for better use of funds.
As the technology is continually enhanced and perfected, it will become possible to land a fixed wing UAV in the tightest of operating windows, making it possible to penetrate areas that simply wouldn’t have been considered in the recent past. Fixed wing UAVs may also be able to more easily land on carriers and conventional ship decks in the near future, where unmanned craft landings might have previously been difficult or unfeasible in some cases.
About the Project and BMT Defence Services
The research project ran for a total of 18 months and resulted in the very first successful landing based on machine learning. For some, it will be unsurprising that BMT was the major stakeholder in the study, considering that they have previously been responsible for numerous developments in the defence industry. The company has worked on projects like the Queen Elizabeth class Royal Navy aircraft carriers, and upgraded missile systems on the Royal Navy’s Type 45 Destroyers.
The company isn’t just involved in military projects, and also conducts operations in salvage, energy, and transportation. BMT also applies engineering expertise to private and civil projects, and was responsible for wind testing on the designs for the Burj Al Arab hotel, the world’s fourth tallest hotel building.
Drone Technology is Advancing at an Astounding Rate
The applications for drone technology have grown significantly in the past decade. Military, public safety, and wildlife tracking, are all areas where drones have had a positive impact. UAVs can also be used for agriculture and mining, as well as for surveying for civil projects. Most recently, drone technology has advanced to a point where craft are used for situational awareness and even climate/environmental monitoring, and in the near future UAVs will even be used for commercial package delivery to consumers.
The perched landing is another milestone in the exciting growth of drone technology, and it will be nothing short of fascinating to see how the UAV industry continues to grow.