IMC-based tuning of PIDA controllers: a comparison with PID control

In this paper we evaluate the performance achieved by a tuning methodology based on Internal Model Control for a Proportional-Integral-Derivative-Acceleration (PIDA) controller. In particular, we compare the results obtained for the set-point and load disturbance step responses with those achieved with a Proportional-Integral-Derivative (PID) controller tuned by applying the well-known SIMC and AMIGO tuning rules. Different high-order processes are considered: self-regulating, distributed lag and non self-regulating. It is shown that, in general, the use of the double derivative (acceleration) action allows the integrated absolute error to be decreased without a decrement of the robustness and with a moderate increment of the control effort.