A relay-feedback automatic tuning methodology of PIDA controllers for high-order processes

In this paper, we present a new automatic tuning methodology for proportional-integral-derivative-acceleration controllers. In particular, a (possibly high-order) model of the process is obtained by means of a relay-feedback test. Then, the four parameters of the controller are determined by approximating the general feedback internal model controller with a truncated Maclaurin series. In this context, the user can select a parameter that determines the speed of the response of the closed-loop system and implicitly handles the trade-off between aggressiveness and robustness. It is shown that the additional acceleration action allows an improvement of the performance with respect to a traditional proportional-integral-derivative controller and represents an effective solution for the control of high-order systems.