Using Petri Net Plans for Modeling UAV-UGV Cooperative Landing

Aerial and ground vehicles working in corporation are crucial assets for several real world applications, ranging from search and rescue to logistics. In this paper, we consider a cooperative landing task problem, where an unmanned aerial vehicle (UAV) must land on an unmanned ground vehicle (UGV) while such ground vehicle is moving in the environment to execute its own mission. To solve this challenging problem we consider the Petri Net Plans (PNPs) framework, an advanced planning specification framework that allows to design and monitor multi robot plans. Specifically, we use the PNP framework to effectively use different controllers in different conditions and to monitor the evolution of the system during mission execution so that the best controller is always used even in face of unexpected situations. Empirical simulation results show that our system can properly monitor the joint mission carried out by the UAV/UGV team, hence confirming that the use of a formal planning language significantly helps in the design of such complex scenarios.