Fuzzy-based variable gain approach for controlling cable-stayedbridges

摘要

Fuzzy- based variable gain control technique is proposed for the vibration controlrnof cable-stayed bridges. The proposed technique is a hybrid method with a two-layer topologyrnin which a lower layer consists of several conventional controllers and a second supervisoryrnlayer possesses a fuzzy inference mechanism for endowing the controller with intelligence. Severalrncontrollers in the sub-layer are separately responsible for the control of individual responsernselected among the multiple target responses of the cable-stayed bridge to be controlled. Then, arnfuzzy supervisor determines the contribution level of each sub-controller to intelligently managernthe overall enhanced control performance of the control system. To investigate the effectivenessrnof the proposed approach, two kinds of vibration control problems have been dealt with: thernseismic response control of cable-stayed bridge and the wind-induced vibration control of cablestayedrnbridge under construction. Example designs and numerical simulations of conventionalrnlinear quadratic Gaussian (LQG) control system and new fuzzy-based variable gain control systemrnhave been performed for the sake of comparison of control performance. The comparativernresults show that the fuzzy-based variable control approach can efficiently reduce the dynamicrnresponses of cable-stayed bridges while maintaining lower level of control efforts, and clearlyrnguarantee the robust performance against the uncertainties of bridge model and seismic eventsrninvolved. Therefore, it is concluded that the proposed technique is an effective control strategyrnfor the vibration control of cable-stayed bridges.