Fuzzy Control of Large Civil Structures Subjected to Natural Hazards

In this chapter, a new semiactive nonlinear fuzzy control (SNFC) system design framework is proposed through integration of a set of Lyapunov-based state feedback controllers and Kalman filters. A nonlinear multi-input multi-output (MIMO) autoregressive exogenous (ARX) Takagi-Sugeno (T-S) fuzzy model is constructed out of a set of linear dynamic models. Subsequently, multiple Lyapunovbased state feedback controllers are formulated in terms of linear matrix inequalities (LMIs) such that the resulting system is globally asymptotically stable. The resulting state feedback controllers are integrated with Kalman filters and a converting algorithm using a T-S fuzzy interpolation method to construct a semiactive output feedback controller. To demonstrate the effectiveness of the proposed design framework, the resulting scheme is applied to a three- and a twenty-story building employing nonlinear hysteretic control devices. It is demonstrated from numerical simulations that the proposed approach is effective in controlling the responses of seismically excited large civil structures equippedwith magnetorheological (MR) dampers: both displacement and acceleration responses of both three- and twenty-story buildings subjected to the 1940 El-Centro earthquake disturbance are dramatically reduced when the proposed control approach is applied.