COMPUTATION OF CLOSED, CONTROLLABLE, AND WEAKLY OBSERVABLE SUBLANGUAGES FOR TIMED DISCRETE EVENT SYSTEMS

Abstract

Brandin and Wonham have developed a supervisory control framework for timed discrete event systems (TDESs). Lin and Wonham have extended this framework to the partial observation case. In our previous work, we have defined a new class of supervisors for TDESs under partial observation. We have introduced a notion of weak observability of languages, and proved that Lm(G)-closure, controllability, and weak observability are necessary and sufficient conditions for the existence of our nonblocking supervisor. These existence conditions of our supervisor are weaker than those of the Lin and Wonham's supervisor. In this paper, we study computation of a closed, controllable, and weakly observable sublanguage of a given closed regular language. We present an algorithm for computing such a sublanguage larger than the supremal closed, controllable, and normal sublanguage.