An efficient liveness enforcing supervisor for FMSs based on Petri nets and the theory of regions

This paper presents an efficient method to obtain a maximally permissive deadlock prevention policy for a flexible manufacturing system based on theory of regions. The theory of regions policy can provides an optimal deadlock prevention controller which is based on the reachability graph. However, its disadvantage is the state explosion problem since all marking/transition-separation instances (MTSIs) have to be identified. For improving the shortcoming, this paper proposes a new concept of the crucial marking/transition-separation instances (CMTSIs). Experimental results indicate that the proposed control policy in this paper is more efficient than the closely related approaches in the literature.