Distributed Cooperative Navigation for Unmanned Aerial System Based on Dynamic Priority

Unmanned Aerial System (UAS) is widely used in commercial shows, wild rescue and so on. Some UAVs may deviate or even crash when GNSS receivers are partially unavailable because of interference or blocked by buildings. This paper aims to provide navigation information for all UAVs when partial GNSS receivers are unavailable. A method of the EKF based on dynamic priority is presented, and it organizes a unidirectional ranging network automatically. Three methods are simulated, the centralized EKF, the Kalman-Consensus Filter and the EKF based on dynamic priority. The proposed method reduces calculation and transmission obviously, and there is no significant difference in position errors. A prototype contains gyroscopes, accelerometers, a GNSS receiver, a processor and a transceiver. The experiment with 4 prototype devices verified the new method. The EKF based on dynamic priority is practical for a large UAS with hundreds of vehicles.