The Similarity Control Problem with Required Events
It extends supervisory control theory to handle required events, addressing a gap for safety-critical systems where certain events must be enabled in specific states.
This paper introduces required events for discrete event systems and solves the similarity control problem under safety and event-enabling constraints, providing a necessary and sufficient condition for solvability and a method for synthesizing a maximally permissive supervisor.
In order to guarantee that a supervised system satisfies safety requirements of the specification, as well as requirements saying that in certain states certain events must be enabled, this paper introduces required events for discrete event systems and reconsiders the similarity control problem while taking all requirements from the specification into account. The notion of a covariant-contravariant simulation, which is finer than the conventional notion of simulation, is adopted to act as the behavioral relation of supervisory control theory. A necessary and sufficient condition for the solvability of this problem is established and a method for synthesizing a maximally permissive supervisor is provided.