| Abstract: | The derivative mode is often omitted in PID control strategies because it proves difficult to arrive by trial‐and‐error at a set of constants which meet plant requirements. The primary objective of this paper was to evaluate several model‐based PID tuning methods. For lag‐dominant processes, it was recommended that the SIMC algorithm first be employed to determine whether satisfactory performance can be obtained with PI control. If it cannot, then derivative action should be introduced using the DS‐d technique. For delay‐dominant systems, IMC tuning is preferred. It was observed that when configured with the same derivative filter factor, the series form of the PID controller produces smoother valve adjustments than the parallel version, at the expense of a slight decrease in best achievable performance. Increasing this parameter improves the control effort but limits achievable performance. |
