Semiactive Nonlinear Control of a Building Structure equipped with Magnetorheological Dampers

This paper proposes a novel design framework for semiactive nonlinear fuzzy control system that is a linear matrix inequality (LMI)-based systematic design methodology for nonlinear control of building structures employing magnetorheological (MR) dampers with multi-objective requirements. Multiple optimum linear controllers are designed in terms of LMIs such that global asymptotical stability and the performance on transient response are satisfied. Then, a semiactive nonlinear fuzzy controller is developed through integration of Kalman estimators and converting algorithms with a fuzzy interpolation method. To demonstrate the effectiveness of the newly developed methodology, an eight story building structure employing multiple MR dampers are investigated. Furthermore, the performance of the proposed nonlinear controller is compared with that of a traditional linear controller, H2/linear quadratic Gaussian (LQG). The simulation results show that the newly developed control system design method is effective in vibration reduction of seismically excited building structures.