The Similarity Control Problem with Required Events

TL;DR

This paper introduces required events in discrete event systems and develops a new simulation-based approach to ensure safety and event enablement requirements, providing conditions for control problem solvability and supervisor synthesis.

Contribution

It proposes a covariant-contravariant simulation framework for supervisory control considering all specification requirements.

Findings

Established a necessary and sufficient condition for problem solvability.

Provided a method for synthesizing maximally permissive supervisors.

Extended the similarity control problem to include required events.

Abstract

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.