An elementary siphon-based deadlock control algorithm with maximally reachable number to cope with deadlock problems in ordinary Petri nets:

摘要

Elementary siphons play an important role in designing deadlock prevention policies for flexible manufacturing systems modeling by Petri nets. This article proposes a deadlock control algorithm with maximally reachable number to cope with deadlock problems in ordinary Petri nets. First, we solve all elementary siphons and dependent siphons and then add both a control place and a control transition to each elementary siphon so that an extended net system (N′,M′) is obtained. Second, by constructing an integer programming problem of P-invariants of (N′,M′), the controllability test for dependent siphons in N′ is performed via this integer programming problem. Accordingly, a few of control places and control transitions are added for those dependent siphons that do not meet controllability as well. Therefore, a live controlled system (N*,M*) with maximally reachable number rather than number of maximally permissive behavior can be achieved. The correctness and efficiency of the proposed deadlock control algo...