A Two-stage Floating Raft Isolation System Featuring Electrorheological Damper with Semi-active Static Output Feedback Variable Structure Control

In this study, a semi-active static output feedback variable structure control (VSC) strategy is presented to control a two-stage electrorheological (ER) floating raft isolation system. A continuous semi-active static output feedback VSC controller is designed and a bypass ER damper is applied to achieve the best control effect more rapidly and accurately. The sliding surface parameters are determined in terms of the Routh—Hurwitz stability criterion. The optimal vibration attenuation of the intermediate mass is guaranteed due to the control rule that damping force only dissipates the vibration energy of the intermediate mass. The robustness of the control method with respect to parameter variations and the effectiveness of vibration isolation are demonstrated by numerical simulation results. It shows that the designed semi-active static output feedback VSC strategy realized by the ER damper can achieve better performance than that of optimally passive damping even if system parameter uncertainties exist. In addition, the experiment was carried out to demonstrate the practical effectiveness of the presented control scheme in this study. The experimental results are satisfied.