Cooperative Multi-UAV Search Problem with Communication Delay

This paper is concerned with a cooperative multi-UAV search problem with communication delay in an uncertain environment. A decentralized decision making approach is proposed to solve the problem. Each vehicle uses a limited look-ahead dynamic programming (DP) algorithm to find its own path. The vehicles share their location and sensor information with each other. However, due to limitations in communication bandwidth, the vehicles are not able to negotiate with each other about their actions. In order to allow cooperation between the vehicles despite such constraints, a stochastic method is proposed to estimate the probability of the different actions for all vehicles. The objective function of each vehicle is modified such that it considers the influence of the different actions of the other vehicles in the team on its own decisions. A similar method is utilized to compensate for the impact of communication delays between the vehicles on mission performance. Finally, these two methods are combined and a general method is introduced to enable cooperation among vehicles in the presence of communication delays. Simulations show that the proposed approach offers improved performance compared to existing approaches.