Characterization of symmetric send-on-delta PI controllers

A new event-based proportional-integral controller, based on a specific send-on-delta sampling strategy, is analyzed in this paper. In particular, necessary and sufficient conditions on the controller parameters for the existence of equilibrium points without limit cycles are given for a first-order-plus-dead-time process. These conditions can be usefully exploited for the tuning of the controller, thus making the overall design easier. Practical issues related to the controller implementation are also addressed. Simulation and experimental results are provided as illustrative examples. © 2012 Elsevier Ltd. All rights reserved.