PROCESS IDENTIFICATION AND CONTROL-BASED ON DOMINANT POLE EXPANSIONS

The dominant pole expansions in terms of the PI controller gains by Hwang and Chang (1987, Chem. Engng Sci. 42, 2395-2415) are extended to cover general PID control systems. The expansion parameters can be estimated via a single response experiment under P, PI, or PID control mode. The identification scheme to accomplish this is based on a first- or second-order plus dead-time model. The proposed tuning method based on the expansions can be easily incorporated in single-loop PID controllers to produce minimum IAE, small overshoot, and robustness for load and set-point changes. Simulation results reveal that the proposed method is valid over a wide variety of processes and superior to many conventional and modern tuning techniques.