A new algorithm for supervisor reduction/localisation of discrete-event systems

Abstract

In this article, we propose a new algorithm for supervisor reduction/localisation of discrete-event systems (DES). Supervisor reduction/localisation is based on merging pairs of states of the supervisor that are control consistent. Our proposed algorithm employs two new lists – a mergeable list and a non-mergeable list – which store state pairs that have been confirmed to be control consistent or inconsistent, respectively. With these two lists, our algorithm eliminates any repeated control consistency checks, and guarantees that every state pair will be checked exactly once. We prove that the time complexity of our new algorithm is O ( n 2 ) , where n is the state number of the supervisor; this improves all previously known results on supervisor reduction/localisation algorithms. We employ numerical examples to empirically compare the computation time and local controller's state number obtained by our proposed algorithm and the original supervisor reduction/localisation algorithms.