A3RHD-SC2 moves toward automated aerial refueling for unmanned aircraft

GMV is participating in A3RHD-SC2, the second phase of a European Defence Agency (EDA) research project aimed at advancing the automation of aerial refueling using the hose-and-drogue system. This phase focuses on unmanned aerial vehicles (UAVs), laying the groundwork for a future in which they could refuel one another in flight.

Spain is leading the second phase, with support from Germany and the addition of Belgium. Spain and Germany also participated in A3RHD-SC1, the project’s initial phase, which demonstrated the technical feasibility of automated aerial refueling. The team also developed camera-based tracking of the drogue and receiving aircraft, and tested methods for stabilizing the drogue during flight.

A3RHD-SC2 will tackle the technical challenges of coordinating multiple receiving UAVs with a single tanker aircraft. The technologies under investigation include relative navigation (which determines an aircraft’s position and movement in relation to another), imaging sensors, aircraft-to-aircraft communications, and the data processing needed to run tracking algorithms.

GMV will provide and develop navigation and data recording capabilities on the drogue side of the system. During A3RHD-SC1, the company supplied the D-SREC (Drogue System Recorder), a unit installed on the drogue to record global navigation satellite system (GNSS) data. In this second phase, GMV will support the development and testing of relative navigation algorithms, enable GNSS data transmission to the tanker aircraft, and introduce the ability to select the GNSS antenna.

The work will proceed in three stages: simulations involving multiple receiving aircraft; laboratory tests using robotic arms to replicate relative movement between the hose and the receiving aircraft; and ground and flight trials to collect data. For the flight tests, Spain will provide a tanker aircraft and Germany a receiving aircraft.