Compositional synthesis of discrete event systems using synthesis abstraction

This paper proposes a general method to synthesize a least restrictive supervisor for a large discrete event system model, consisting of a large number of arbitrary automata representing the plants and specifications. A new type of abstraction called synthesis abstraction is introduced and three rules are proposed to calculate an abstraction of a given automaton. Furthermore, a compositional algorithm for synthesizing a supervisor for large-scale systems of composed finite-state automata is proposed. In the proposed algorithm, the synchronous composition is computed step by step and intermediate results are simplified according to synthesis abstraction. Then a supervisor for the abstracted system is calculated, which in combination with the original system gives the least restrictive, nonblocking, and controllable behaviour.