On state-space compression and state reachability retrieval of Petri nets

Abstract

The problem of state-space explosion and state reachability decision has been a focus in Petri net analysis. In this article, some algorithms based on data features of state space are proposed for state-space reduction and reachability analysis in Petri nets. A caching arrangement algorithm for the state reachability graph is proposed to alleviate the memory overhead when all states are generated by a traditional reachability graph generation algorithm. For the reduction of the state space, a compression algorithm based on a hybrid coding is formulated. The changing characteristics of state elements are fully utilized to realize a sharp reduction of the whole state space. For the state reachability analysis, a state reachability retrieval algorithm based on the locally sensitive hashing is reported. In this algorithm, all the states in the compressed state space are distributed to different hash buckets according to the distances among the states, which realize the primary state retrieval efficiently. Then, a state retrieval strategy that reverts the primary retrieved state to its original data is adopted. Finally, the proposed compression and retrieval algorithms are validated on several Petri net models, showing high compression efficiency and exact accuracy of state retrieval.