Study on relabeling observer property in symmetric discrete-event systems
JIAO Ting
GAN Yong-mei
XIAO Guo-chun
WONHAM W M
Abstract：Symmetry arises when discrete-event systems (DES) consist of groups of identical components. To reduce the state space of symmetric DES, the event relabeling map is proposed in this paper. The event relabeling map relabels all events fulfilling the same task to one symbol and treats uncontrollable events irrelevant to control as unobservable events. Then the unobservable events are erased by relabeling them to the empty symbol. To ensure that the supremal controller remains control-equivalent after relabeling, the concept of relabeling observer property (ROP) is proposed, as well as steps to determine whether certain languages have this property. Based on the ROP, we show that the original supervisor and its relabeled counterpart are equivalent in control action. Namely, the reduced supervisor in the relabeled system achieves the same control goal as the supervisor in the original system before relabeling. Finally, examples are given to illustrate the validity of the proposed approach.
Keywords：discrete-event systemssupervisory control theorysymmetryevent relabeling
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 525-532 )