Relative Navigation of UAV Swarm in a GPS Denied Environment1

A precise relative localization system is a crucial necessity for a swarm of Unmanned Aerial Vehicles (UAVs), particularly when collaborating on a task. This paper aims to provide an alternative navigation system to enable a swarm of UAVs to conduct autonomous missions in a Global Positioning System (GPS)-denied environment. To achieve this goal, this paper proposes a relative navigation system using an Extended Kalman Filter (EKF) fusing observations from the on-board Inertial Measurement Unit (IMU) with ranging measurements obtained from the on-board ranging sensors. To ensure secure and high data communication rates, the system employs two waveforms and a low-cost beam-switching phased array. This system thus enables drone operations even in GPS-denied environments. We demonstrate the effectiveness of our approach through simulation experiments involving a swarm of six drones, which includes three fixed and three moving drones in a challenging Blue-Angel scenario. The evaluation of the statistical tests on the results of the simulations shows that this method is efficient.