A Method for the Synthesis of Deadlock Prevention Controllers in
Systems Modeled by Petri Nets
M.V. Iordache, J.O. Moody, and P.J. Antsaklis
Proceedings of the 2000 American Control Conference, Chicago, IL, June
28-30, 2000.
Abstract --
Given an arbitrary Petri net structure, the deadlock prevention procedure
presented here determines a set of linear inequalities on the marking of a
Petri net. When the Petri net is supervised so that its markings satisfy
these inequalities, the supervised net is proved to be deadlock-free for
all initial markings that satisfy the supervision constraints.
Deadlock-freedom implies that there will always be at least one transition
that is enabled in the closed loop (supervised) system. The method is not
guaranteed to insure liveness, as it can be applied to systems that cannot
be made live under any circumstances. However, it is shown that when the
method does insure liveness, it is at least as permissive as any other
liveness-insuring supervisor. The procedure is illustrated using an
example from flexible manufacturing.
[postcript file][pdf file]