Formal synthesis of supervisory control software for multiple robot systems

This paper demonstrates the application of a range of theoretical tools to generate real-time control software for multiple ground robots working together cooperatively. Specifically, existing discrete event system theory is applied to synthesize high-level supervisory control logic that is guaranteed to maintain the behavior of multiple robots within requirements defined by a set of formal specifications. The modeling of the high-level behavior of the robots in their given environment, as well as the formal specifications, is described in detail. The resulting models are represented as finite-state automata. In this work we assume that some events cannot be controlled, though all events are assumed to be observable. In addition to generating control logic that is guaranteed to keep the robots safe, results are also presented for choosing from amongst a set of allowed robot behaviors in order to achieve behavior that is “good” in some sense. Specifically, a modified version of Dijkstra's algorithm is employed to choose a path through the finite-state automaton representing the allowed robot behaviors. This modified algorithm is able to address multiple robots and the fact that some events cannot be controlled (commanded). The resulting high-level robot events are then connected to the continuous, time-driven behavior of the robots through a series of low-level algorithms. The result of this work is demonstrated in simulation for a simple, but demonstrative scenario.