Formation Flight of Fixed-Wing UAVs: Dynamic Modeling, Guidance Design, and Testing in Realistic Scenarios

Autonomous unmanned flight based on fixed-wing aircraft constitutes a practical and economical solution for transport missions to remote destinations or disadvantaged communities, for which their payload and range represent interesting figures of merit. In such contexts, the use of UAV swarms presents an attractive approach to leveraging payload capabilities. Additionally, within the military domain, deploying swarms of smaller aircraft could enhance logistic modularity, reducing the risk of losing the entire mission cargo or supply of weaponry when traversing hostile territories. The literature on swarms of fixed-wing aircraft is mostly related to control design aspects, often demonstrated via simplistic modeling in virtual environment, or to performance analyses carried out on experimental setups, which typically try to cope with the complexity of real-time management, integration within a multi-agent scenario, and the tactical issues arising when facing an actual flight. This paper fits in the gap between these approaches. It introduces an accurate 6-DOF flight dynamics model of a fixed-wing UAV, which was employed for the synthesis and testing of the stabilization and guidance laws for a swarm within a high-fidelity simulation environment. Furthermore, in the same environment, a scheme for intra-swarm coordination was designed and demonstrated, accounting for optimal aerodynamic performance. The performance of coupled swarm guidance and formation control algorithms was analyzed and tested in the case of realistic missions, also demonstrating the ability of the proposed overall control scheme to operate in the presence of disturbances.