Analytical design of two degree-of-freedom decoupling control scheme for Two-by-two systems with time delays and integrators

A new two degree-of-freedom decoupling control scheme is proposed for Two-by-two systems with multiple time delays and integrators. Its´ main feature is that the disturbance responses are decoupled from the set-point responses. Firstly an inverse model based decoupler is proposed. Then the set-point tracking controller is analytically derived in terms of the H₂ performance specification. The controller that is responsible for rejecting load disturbances and therefore is called a disturbance estimator is analytical derived by proposing the desired transfer function for disturbance rejection. Meanwhile, the sufficient and necessary constraints for tuning the proposed controllers to hold the control system robust stability are analyzed in the presence of the process multiplicative uncertainties. A simulation example is included to show the effectiveness of the proposed method.