Smith predictor control and internal model control - a tutorial

This paper is to provide a guide to the time-delay compensation scheme known as Smith predictor control which uses feedback loop for controlling any system. The Smith predictor control was devised to remove the delay effect from the closed-loop design, and is equivalent to IMC in the sense that the delayed behavior of the plant is cancelled by the plant model. The internal model control (IMC) scheme is discussed together to understand the Smith predictor control in terms of newer theoretical concepts. Related topics such as disturbance rejection, /spl Hscr//sub 2/ optimality, stability, robustness, MIMO systems, SISO systems and windup problem are also discussed.