Optimal Design of Two-Degree-of-Freedom Control Scheme for Integrating Processes with Time Delay

An analytical two-degree-of-freedom (TDOF) control scheme for integrating processes with time delay is proposed in this paper. Performances of both set-point tracking and input load disturbance rejection (ILDR) can be improved by the proposed method. Firstly, all controllers which make the closed loop system internally stable and have no steady-error have been employed. Secondly, the set-point tracking controller and the disturbance rejection controller are analytically derived in terms of the integral-squared-error (ISE) performance specifications. The nominal set-point response is decoupled from the load disturbance response in the adopted TDOF control scheme. In consequence, both of the set-point tracking performance and load disturbance rejection performance can be optimized simultaneously and separately. Finally, simulation results are given to demonstrate the superiority of the proposed method.