Coordination and Control of Distributed Discrete-event Systems subject to Sensor and Actuator Failures

We study the coordination and control problem of distributed discrete-event systems with synchronous communication, in the presence of subsystems whose sensors and/or actuators may be affected by unexpected failures. We model sensor failures as permanent loss of observability of certain sensor events that belong to a subsystem, while characterize actuator failures as loss of controllability of the subsystems’ actuator events. The failure tolerance property requires that the distributed discrete-event systems satisfy a global specification prior to as well as after occurrences of potential failures. To prevent the failure-pruned subsystems from jeopardizing the fulfillment of the specification, we propose automaton-theoretic frameworks corresponding to the enforcement of sensor and actuator failure tolerance by incorporating learning-based supervisor synthesis and coordination approaches with appropriate post-failure control reconfiguration schemes. The effectiveness of the proposed frameworks is demonstrated by an illustrative example.