Classification of Reachable Markings for Automated Manufacturing Systems with Multiple Unreliable Resources

It is a hot issue to discuss the robust control policy for automated manufacturing systems (AMSs) with unreliable resources in recent years. Before designing a robust controller, it is necessary to analyze the production processes of AMSs with unreliable resources. In our work, we study the classification of production states for AMSs with multiple unreliable resources. First, Petri nets are utilized to model the above systems. Second, the reachable markings of Petri nets describing undesired production states are classified into four types, such as deadlocks, F-deadlocks, F-blockings and FP-blockings by the structural characterization, maximal perfect resource-transition circuits, of Petri nets. Next, we prove that all undesired reachable markings are only the above four types for a kind of AMSs with multiple unreliable resources. Finally, an algorithm to compute all deadlocks, F-deadlocks, F-blockings and FP-blockings with low computational complexity is presented, and an example is utilized to illustrate the validity of the conclusion and the algorithm.