Discrete Event System Models

This chapter introduces formally the discrete event system models used to solve different path‐planning problems for a team of robots that should achieve a common goal. This goal is in general a high‐level specification and, as mentioned in the previous chapters, the methods working on the continuous state space are difficult or even impossible to be applied. For this reason, once the state‐space is discretized, graph‐based algorithms and mathematical programming approaches can be applied to solve the planning problem. Two types of discrete models will be presented, which will be used in the following chapters to solve some particular problems. The first type of model is based on transition systems, mainly used for solving path‐planning problems for a single robot or teams with few robots (usually 2 or 3). The second type of models are based on Petri nets that are scalable with respect to the number of robots.