Radio Source Localization by a Cooperating UAV Team

This paper describes the development of a networked UAV communication, command, and control (NetUAVC3) architecture. The NetUAVC 3 project is divided into three stages. Stage 1 focused on developing algorithms for tying network intelligence and mission-level tasking information into automatic flight controls. Stage 2 will conclude with a demonstration of leashing UAVs to mobile nodes, and Stage 3 will conclude with a demonstration of radio source localization by a cooperating UAV team. This presentation will describe the NetUAVC 3 architecture currently under development. The Stage 1 system will be presented, including the onboard flight management architecture and monitoring and command control software that exploits the existing AUGNet mesh network. The radio localization problem, in which one or more UAVs react cooperatively to localize the location of a radio emitter, will also be introduced. Source localization is cast as a distributed estimation problem. Aircraft mobility is exploited to improve the observability, in terms of the Fisher Information Matrix, of this estimation problem. Aircraft motion is coordinated through iterative consensus by individual receding horizon controllers on each vehicle. Nomenclature (x,y,ψ) = 2D x-position, y-position, and heading of UAV U = constant UAV speed ui = turn rate command of ith UAV ωmax = maximum turn rate command xi,x = vector state of ith UAV, entire UAV team u = input vector for entire UAV team pj = 2-D position vector or jth radio transmitter Pj = Received power of jth transmitter P0,d0,k0,e = Parameters of empirical radio propagation model tj,t = vector state of jth radio transmitter, set of all transmitters zi,zi,z u k = measurement by ith UAV, measurement vector of entire UAV team = control input sequence, optimal input sequence