Maximally Permissive Supervisory Control with Forcible Events

This paper proposes a supervisory control theory that allows the supervisor to not only enable/disable events, but also force specific events (called forcible events) that can preempt uncontrollable events. The authors define a notion of forcible-controllability that captures the interplay between controllability of a supervisor and the uncontrollable events provided by a plant in the setting with event forcing. They show the existence of a maximally permissive, forcibly-controllable, nonblocking supervisor and provide an algorithm to compute such a supervisor.