Distributed extended finite-state machines: communication and control

Abstract

We propose to implement decentralized supervisory control by embedding the control map in the plant's local finite state machines (FSMs) and employing private sets of Boolean variables to encode the control information for each component supervisor. Event observation is captured by a set of Boolean functions that update the value of Boolean variables, and control is introduced by guarding events with Boolean formulas. We extend the previous results for centralized control problems to the decentralized case with coobservable specifications. Next, a characterization of coding algorithms suitable in studying decentralized control problems is presented and shown to relate to a modified version of joint observability of the specification. In the absence of coobservability, the problem of communicating supervisors is then studied and solutions are proposed for certain classes of specifications