The 2-port control system

The 2-port control structure is introduced to develop a complete framework for the analysis and design of robust predictive controllers. It is particularly suited for the optimum resolution of controller design trade-offs, such as performance to set-point tracking vs. disturbance rejection, and performance at various frequencies. Furthermore, the 2-port control structure allows the transparent design of effective controllers for processes with non-minimum phase characteristics, or inherently unstable open-loop dynamics. Finally, it offers, the necessary and sufficient conditions for the design of effective adaptive control strategies. Various illustrations are also provided to demonstrate the relationship of the 2-port control structure to other design frameworks, such as internal model control (IMC), and conventional feedback with analytic predictors.