Time-triggering versus event-triggering control over communication channels
For control theorists and engineers, this work provides a theoretical comparison of two control strategies under communication constraints, but the results are incremental extensions of prior work.
The paper compares time-triggered and event-triggered control for stabilizing an unstable plant over a rate-limited channel with unknown bounded delay, finding a critical delay where information loss from delay compensates the implicit information from event triggering. It extends previous event-triggering results to vector systems and extends the data-rate theorem for time-triggered control to unknown delay.
Time-triggered and event-triggered control strategies for stabilization of an unstable plant over a rate-limited communication channel subject to unknown, bounded delay are studied and compared. Event triggering carries implicit information, revealing the state of the plant. However, the delay in the communication channel causes information loss, as it makes the state information out of date. There is a critical delay value, when the loss of information due to the communication delay perfectly compensates the implicit information carried by the triggering events. This occurs when the maximum delay equals the inverse of the entropy rate of the plant. In this context, extensions of our previous results for event triggering strategies are presented for vector systems and are compared with the data-rate theorem for time-triggered control, that is extended here to a setting with unknown delay.