Joint Optimization of Connectivity, Coverage, and Revisit Time in Multi-UAV Path Planning

Multi-UAV systems are deployed for many civil applications, such as search and rescue, surveillance, environmental monitoring, that require efficient area coverage and connectivity between UAVs and ground control station (GCS) to enable teamwork and information exchange. In dynamic missions, such as disaster management, or in case the sensors on the UAVs lead to uncertain measurements, it is desirable that whole or part of the area of interest is revisited by UAVs for information update or reliability. In this work, we propose a novel multiUAV path planning algorithm that incorporates revisit times into path decisions, without compromising coverage and connectivity requirements. We model the proposed planner by a multiobjective optimization problem and we provide an NSGA-II based solver that leads to a set of Pareto-optimal solutions. We compare our results with a benchmark path planner that only optimizes coverage and connectivity and show the tradeoffs between the proposed objective functions. We observe up to 4-fold improvement in terms of observed times between revisits.