On the impact of communication delays on UAVs flocking behavior

Communication delay plays an important role for the safety in a Cyber Physical System (CPS). Self-organized flocks of UAVs (Unmanned Aerial Vehicle) are a particularly highly dynamic and complex example of a CPS. Since flocking algorithms rely on the exchange of position and velocity information, high communication delays may lead the flock to an oscillatory behavior. This behavior increases the probability of collisions. In the literature, some conceptual methodologies for verifying safety in CPS have been discussed. They mainly proposed to identify states or actions, that may affect the safety. In this paper we analyze the impact of communication delays on the safety of a flock of UAVs. We introduce an architecture for an UAV, that simulates the asynchronous behavior of different components. We used our self-organized flocking algorithm to evaluate this architecture using different communication delays. Thus, we estimate the communication delay constraints for 2, 3 and 5 UAVs for the safe operation of the given flocking algorithm.