Semi-active fuzzy control of cable-stayed bridges using magneto-rheological dampers

A semi-active fuzzy control technique to enhance the seismic performance of cable-stayed bridges using magneto-rheological (MR) dampers is presented. Conventional semi-active control techniques require a primary controller as a reference to determine the desired control force, and modulate the input voltage of the MR damper by comparing the desired control force and the actual damper force in a secondary controller. The proposed method, however, adopts fuzzy logic instead of primary and secondary controllers. The fuzzy logic directly determines the input voltage of an MR damper from the response of the MR damper. Thus, it provides a simple design procedure and can be easily implemented on a physical structure. The control performance of the proposed fuzzy control technique for the MR damper was evaluated for the benchmark control problem of a seismically-excited cable-stayed bridge. The simulated results show that the proposed semi-active fuzzy control technique can effectively mitigate the seismic response of cable-stayed bridges and successfully enhance the robust performance of the MR damper system.