Energy-Based Cooperative Control for Landing Fixed-Wing UAVs on Mobile Platforms Under Communication Delays

The landing of a fixed-wing UAV on top of a mobile landing platform requires a cooperative control strategy, which is based on relative motion estimates. These estimates typically suffer from communication or processing time delays, which can render an otherwise stable control system unstable. Such effects must therefore be considered during the design process of the cooperative landing controller. In this letter the application of a model-free passivity-based stabilizing controller is proposed, which is based on the monitoring of energy flows in the system, and actively dissipating any given active energy by means of adaptive damping elements. In doing so, overall system passivity and consequently stability is enforced in a straightforward and easy to implement way. The proposed control system is validated in numerical simulations for round trip delays of up to 4 seconds.