Supervisory control for systems of vehicles in path networks

The paper is twofold. First we introduce a new concept-a partially directed graph, in which an edge can be undirected or have one of the two possible directions-and examine some of its structural properties. Then we assume that the edge attribute is variable and employ the concept to build a general, discrete event model of a system of vehicles moving in a path network. We examine some dynamic properties of the model and develop a flexible, suboptimal policy ensuring safe operation of the vehicle system.