Robust formation shape control for fixed-wing unmanned aerial vehicles with relative pose measurement

This paper addresses the robust formation shape control problem for fixed-wing unmanned aerial vehicles (FWUAVs) with relative pose measurements. Firstly, the robustness of the formation shape is determined such that the desired position of each follower is given relative to the unified leader in a swarm of FWUAVs, instead of the frequently used relative positions measured by pairs of neighboring vehicles. Secondly, in the GPS-denied environment, a forward formation shape control scheme under a directed tree graph for FWUAVs which utilizes local relative pose measurements between neighboring vehicles together with communicated leader velocity information, without requiring global GPS signals. This controller includes translational and rotational inputs, which are tightly linked through the constructed intermediate attitude. The stability of the closed-loop error system and the rationality of the intermediate attitude are demonstrated via the Lyapunov approach. Finally, the performance of the proposed controller is verified by using numerical simulation and experiment.