In future, electric drones may be able to cover much greater distances without lengthy interruptions for recharging. By enabling drones to swap their batteries autonomously whilst in flight, their range can be significantly extended.
The technology that makes this possible has been developed by the Aero student team at Eindhoven University of Technology (TU/e). During a test on campus, a drone managed to land autonomously on a specially designed platform on the roof of a car, secure itself mechanically and, without human intervention, replace an empty battery with a fully charged one.
Three components tested
During the demonstration, the team tested three key components of the system in conjunction with one another. The drone performed an autonomous precision landing, mechanically docked with the platform and then automatically swapped the battery. All these operations were carried out entirely automatically.
The trial marks a significant milestone for Team Aero. The team is working on a system that will eventually allow batteries to be replaced in flight rather than on the ground. According to the team, the current battery-swapping process is one of the biggest limitations for electric drones. As this requires the drone to land, it restricts both the range and the operational flexibility of drones.
Ultimately, the project is intended to lead to what is known as an In-Flight Battery-Swap System. This would enable a drone to swap a flat battery for a charged one whilst in flight, without the need to land.
Time saved
In practice, this saves time. Drones no longer need to be charged on the ground and can continue flying immediately after the swap. Furthermore, the battery is swapped automatically, resulting in less downtime. Thanks to this capability, the student team envisages new applications, including in logistics and agriculture.
Incidentally, the concept should also make it possible to swap objects other than a battery. Think, for example, of a parcel attached beneath the drone. The team does emphasise, however, that several technical steps are still required before this can be put into practical use.
Drone-to-Car setup
The demonstration utilised a so-called ‘Drone-to-Car’ setup. The drone coordinated its flight with the docking platform, which was mounted on the roof of the car. Following a controlled landing on this platform, the drone was secured using a mechanical locking system.
The drone then autonomously removed the flat battery from its system, inserted a charged one and automatically locked the new battery into place.
In-flight battery replacement
The next phase of the project focuses on carrying out a battery swap whilst the drone is in flight. During the 2026–2027 academic year, the team aims to design and build a new drone in which the battery swap system is integrated into the structure. This drone will ultimately serve as the receiving drone, into which the replacement battery will be inserted. The current drone platform is expected to be used as a transport drone carrying the charged battery.
In due course, the students aim to carry out a new demonstration using these two drones. During this demonstration, the drones will need to dock with each other whilst in flight and carry out a battery swap autonomously.
This is not without its challenges. For instance, both drones cause turbulence, which makes it difficult to bring them together precisely and ensure they dock safely. This requires highly precise control and coordination between the drones.
Team Aero
Team Aero currently consists of fifty students. Three board members focus full-time on the team’s work, prioritising it over their studies. The other members combine their work with their studies. The students come from nine different fields of study and represent thirteen nationalities.
The team was formed five years ago following a merger between the Blue Jay student team and the SyFly honours programme. Since then, Aero has been focusing on the development of autonomous drone technology in the Brainport region. The current project centres on applications for the air freight sector.
According to the team, it is precisely this sector that poses a challenge to further electrification. Air transport is responsible for significant CO₂ emissions, whilst the limitations of current battery technology are hindering the transition to fully electric aviation. By developing a system that allows batteries to be replaced whilst in flight, Team Aero aims to overcome this problem.
Drone network
The team’s vision is based on a network in which drones efficiently transport priority parcels between logistics hubs. This means a drone does not need to return to a charging station as soon as its battery is running low.
Instead, a smaller drone would take off from a nearby battery station, dock with the transport drone during flight and replace the empty battery with a charged one. Both drones would then continue on their respective routes.
