Robust Supervisory Control Against Intermittent Loss of Observations

We address in this paper the design of robust supervisors for discrete-event systems subject to intermittent loss of observations. We present two definitions of robust observability: a more restrictive one that requires that the language achieved by the supervisor that control the nominal plant be also achieved by the robust supervisor, and a weaker one that also takes into account possible observation of the events that are subject of intermittent loss of observations. Necessary and sufficient conditions for the existence of robust supervisors that make the controlled system achieve weakly and strongly robust observable languages are also presented. A running example illustrates all the results presented in the paper.