Intelligent PI control design for maximum sensitivity and stability margins

An approach is proposed for the design of PI control based on specifications of maximum sensitivity and stability margins. The approach uses a closed-loop assessment of these robustness indicators to tune the PI controller such that desired and improved specifications can be met closely. Guidelines are given for a set of generally satisfactory specifications. The PI control parameters are obtained via the minimization of objective functions, which are derived to fit these robustness characteristics of the compensated system as closely as possible to the user specifications. A simulation study of the control design on commonly encountered processes would show the effectiveness of the proposed scheme.