An automatic tuning procedure for an event-based PI controller

In this paper we propose an automatic tuning procedure for an event-based PI control scheme. In particular, the well-known relay feedback methodology for a standard PI controller is extended to a symmetrical send-on-delta PI controller. In this context, the overall event-based procedure consists of two relay feedback experiments (with a PI controller, possibly roughly tuned, already in place) in order to estimate the parameters of a first-order-plus-dead-time transfer function. Then, based on the process parameters, a tuning rule can be suitably applied. Simulation results demonstrate the effectiveness of the methodology.