Communication-Free Formation Flight Control for Autonomous Fixed-Wing UAVs in GNSS-denied environments

This article presents a novel formation control strategy for a group of fixed-wing unmanned aerial vehicles (UAVs) in GNSS-denied environments without communication links. Each aircraft will only have access to the relative states measured using its onboard sensors and to an alternative source of absolute navigation. The presented approach is based on a controller which is a function of the state estimation error, allowing the aircraft with high accuracy data to have a greater contribution to the formation guidance and reducing the effect of those with less precise information. The approach has been tested in a simulation environment over a series of scenarios including different sensors and configurations, showing that the proposed control strategy allows to reduce the deviation with respect to the nominal path in the presence of process noise and data uncertainties.