Three-Degree of Freedom Internal Model Control

To improve the robustness and disturbance rejection performances of the control system, a three-degree of freedom control design algorithm that extended from internal model control is proposed. For robustness of the control system, which based on the knowledge of the model uncertainties, the internal model control structure is adopted together with an additive robust compensator. The controller used for disturbance rejection is designed according to sensitivity function of the three-degree of freedom control system. The straightforward timing of few parameters gives the technique its practicality. Numerical examples are given to illustrate the algorithm, which provides verification and insight