A two-stage floating raft isolation system featuring electrorheological damper with semi-active fuzzy sliding mode control

In this article, a semi-active fuzzy sliding mode control (FSMC) strategy for the vibration attenuation is presented based on the fact that for two-stage electrorheological (ER) damper floating raft isolation system, the upper bounds for uncertainty external disturbance and the parameters perturbation are hard to estimate in advance, and the damping force of ER damper is controlled continuously. The parameters of sliding surface are selected based on Hurwitz stable judgement of sliding mode motion equation. Fuzzy controller is designed in terms of the sliding mode reaching condition and the maximal damping force of ER damper. 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 main object. The robustness of the proposed semi-active FSMC method with respect to parameter variations and the effectiveness of the controller designed in this study are demonstrated by numerical simulation. It showed that the proposed semi-active FSMC strategy realized by the ER damper can achieve better performance than those of optimally passive damping and maximum damping variety even if system parameter variations 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.