Robust inversion feedforward and H∞ mixed sensitivity feedback based 2DOF MIMO control

This paper proposed a MIMO 2DOF control design approach based on robust inversion feedforward and H^∞ mixed sensitivity feedback control. The proposed 2DOF control approach utilizes inversion feedforward control to improve the tracking performance of system, and H^∞ feedback control to reject external disturbance, compensated tracking error and improve system robustness. At first, a static pre-compesator to render the MIMO system diagonally dominant design method is presented, then the 2DOF MIMO control system is developed followed by designing the inversion feedforward controller according to the nominal model and the uncertainty of the compensated system, and designing the H^∞ mixed sensitivity feedback controller according to the requirement of the robustness and tracking performance. The results of simulation experiment demonstrated the proposed control approach could improve the tracking performance of MIMO system effectively.