Automatic Recovery of Fixed-Wing Unmanned Aerial Vehicle Using Bluetooth Angle-of-Arrival Navigation

We demonstrate that the Bluetooth 5.1 Angle-of-Arrival feature can be used as a navigation system for automatic recovery of a fixed-wing unmanned aerial vehicle (UAV), guiding the UAV into an arrest system such as a suspended net, independently from global navigation satellite systems (GNSS). The effect of multipath signal interference on the elevation angle estimate is handled by a constant offset calibration. In field experiments, we demonstrate approach path following using a Skywalker X8 fixed-wing UAV and a Bluetooth antenna array. For 39 approach repetitions the resulting impact positions 40m in front of the array had standard deviations of 0.41m horizontally and 0.32m vertically according to precise RTK GNSS positioning used for comparison.