State Estimation for Decentralized Supervisory Control of Discrete-Event Systems with Communication Delays

In this paper, we investigate the state estimation of decentralized supervisory control of discrete-event systems (DESs) subject to random observation delays and control delays. We assume that each local supervisor is connected to the plant via an independent observation channel, and the control commands issued by each supervisor are delivered to the fusion site via an independent control channel. Communication delays exist in both the observation channels and the control channels. In our previous work, we have analyzed how each local supervisor interacts with the plant and the fusion site under communication delays. In this paper, we investigate the state estimation problem for the supervised systems based on strings communicated to the local supervisors. The estimation algorithm considers the effect of controls imposed on the systems. Additionally, the estimation algorithm is based on the control decisions available up to the moment, and all the future control decisions made by the local supervisors are assumed to be unknowable.