New hybrid optimal controller applied to a vibration control system subjected to severe disturbances

Abstract

Abstract This study presents a new hybrid optimal controller to enhance the robustness and stability of dynamic systems subjected to uncertainties and external disturbances. In the formulation of the proposed control system, the Bolza–Meyer (BM in short) criterion of the optimal controller is modified to meet the system variation, and the sliding-mode controller is modified to obtain the classical control property with the prescribed performance. The proposed controller also includes the H-infinity technique as a bridge for connecting the sub-controls and improving the robust performance of the system. Fuzzy model are used as filters to choose the optimal values for the next calculation. Hence, many advantages of fuzzy model are acquired, related to optimal control, sliding mode control, prescribed performance, and H-infinity techniques. To demonstrate these advantages, the proposed hybrid controller is applied to a vehicle seat suspension for vibration control. Superior control performance over existing hybrid controllers is demonstrated in both time and frequency domains.