State Estimator Design of Event Graph with Unobservable Transitions

In order to overcome the problems in the state estimation of unobservable transitions in event graph modeling for discrete event systems,the concepts of pre/post observable paths are proposed to analyze the problem in detail,and a design method is presented for the state estimator to estimate the unobservable transitions according to the row trans- formation of the incident matrix.The observation cost is analyzed and then a method is provided to search the optimal estimator,which is used to estimate the state-range of unobservable transitions.Finally an example is described to prove the effectiveness of the presented method in state estimation of unobservable transitions.