In: 38th IEEE Conference on Decision and Control. December 1999.
Abstract: We design a supervisor which enforces k-safeness in state machines, i.e. the marking of every place is not allowed to be greater than k, and which is itself a Petri net. This is done by extending the control design method based on invariants to Petri nets which contain uncontrollable transitions. We show that this supervisor is maximally permissive - disables as few transitions as possible - and is minimal - contains as few control places as possible. Finally, we show that the design of the supervisor can be done using min-plus algebra.