Swarm flight for UWB-based reference trajectory tracking

Autonomous flying vehicles represent an innovative solution for various service robotics scenarios. In particular, the capability of acting in formation opens to new opportunities in a multiplicity of different fields. One of the many advantages of having multiple Unmanned Aerial Vehicles (UAVs) operating collaboratively is the possibility to sense the relative distances from an object and localize it with respect to their position in space. The case analyzed in this document consists of a reference body, be it terrestrial or aerial, autonomous or human-controlled, that operates in a GNSS-denied environment: computing its position at all times is a fundamental challenge, that is overcome thanks to the information exchanged with a fleet of drones. This work aims to study and implement techniques to perform two combined tasks: maintaining a steady formation of the UAVs and tracking the trajectory of the considered reference body. In particular, a potential-based decentralized algorithm was deployed for the swarming task, while a centralized approach was chosen to fulfill the tracking requirement. The studied procedures make use of the GNSS position of the swarm anchors, and the relative distance between each couple of vehicles, given by the Ultra-WideBand (UWB) sensors mounted on every machine. The achievement of the described objectives, and the data provided by the sensors onboard every vehicle, give the possibility to easily localize the reference body in space, via a multilateration approach. The results of the performed simulations show good tracking capability, while successfully keeping a stable group flight configuration in all tested conditions.