On Intrinsically Live Structure of a Class of Generalized Petri Nets Modeling FMS
Résumé
From the perspective of structure theory, the deadlock control and liveness-enforcement are
mostly implemented based on siphons in most existing work. In our previous work, a kind of intrinsically
live structures is proposed in a class of generalized Petri nets, weighted S3PR (WS3PR). The livenessenforcement
is achieved by analyzing the structure including weight information and reconfiguring the
initial marking of resource places without considering the initial token counts in idle places. In this work,
the method is extended to a more general subclass than WS3PR. Instead of siphons, a new concept of
structural objects is defined to carry weight information and reflect the circular waits of resources. The
numerical relationship between initial markings of resource places and weighs of arcs is investigated to
yield an intrinsically live structure-based liveness-enforcing method that requires no external monitors.
The work provides an insight into structures of generalized Petri nets and a new angle of the deadlock
control. Several examples are used to illustrate this method.