Autonomy levels versus communication in an underwater environment

The SEATONOMY methodology is a systematic approach to make efficient the design, development and verification and validation of autonomous systems. The relationship between levels of autonomy (LOA) and availability of communication is an important factor for underwater drones. Underwater autonomous operations experience both a reduction in available communication capacity and increased propagation delay as the drone moves away from the central hub. This must be included in the system dynamics design and operation planning. Based upon the interpretation of Sheridan's ten LOAs, we introduce in this paper an overall user/drone system with a simple illustration of the relation between communication capacity and delay for a direct link between a user and a drone. The results show that the instant operational LOA for a drone as it moves along in the water is lower bounded by the LOA resulting from observing the jointly influence of communication and delay. Simulations of the communication link based on input from hydrodynamic modelling reveals the fluctuation of the instant LOA along the drone's path. Including adaptivity in the instant LOA of a drone is helping to increase the robustness of its performance and handling of abnormal or unexpected situations.