Distributed Low-Complexity 3D Cooperative Positioning using Projection FG for UAV Networks

Precise unmanned aerial vehicle (UAV) localization is crucial for the successful operation of UAV swarms, particularly in environments where global navigation satellite system (GNSS) signals are denied or unavailable. This paper introduces a cooperative positioning framework for such scenarios. Considering the resource and coverage constraints of UAVs, a multi-objective cooperative positioning algorithm using a projection factor graph (FG) is proposed. This algorithm achieves dimensionality reduction and interaction of the positioning message among UAVs, employing low-complexity techniques for parameter estimation. Simulation results demonstrate that the proposed algorithm achieves linear complexity, significantly lower than cooperative benchmarks like SPAWN with cubic. Furthermore, it provides an 82.5% increase in positioning accuracy over non-cooperative methods, yielding accuracy approaching that of the high-complexity SPAWN algorithm.