Synchronization of State Based Control Processes with Delayed and Asynchronous Measurements

This paper addresses the problem of controller state synchronization in a networked control system with distributed sensing and actuation, where actuators must hand off and switch controllers "on the fly" as they go from performing one task to another, in the presence of fixed communication delays and asynchronous measurements. We present a technique that enables new controllers to seamlessly join and leave a task, by encapsulating the controller in a finite state machine that handles the synchronization. We also discuss issues related to the real-time implementation of this technique and we finish with a demonstration on an example from the document printing domain.