Performance and robustness trade-offs in PID control

• Presents trade-off plots that give insight into constrained PID control design.
• Provides tuning intuition.
• Compares common PI tuning methods, exposing their strengths and weaknesses.
• Presents a parametrization of optimal controllers.

Control design is a rich problem which requires consideration of many issues such as load disturbance attenuation, set-point tracking, robustness with respect to process variations and model uncertainty, and effects of measurement noise. The purpose of this paper is to provide insight into the trade-offs between performance and robustness explicitly. This is accomplished by introducing plots that show the trade-offs for PI and PID control. These also provide valuable understanding of design compromises used for common PI design methods.