Development and application of nonlinear controller using variable damping devices

To improve the safety of building structures for large earthquakes, a nonlinear controller which utilizes variable damping devices is presented. The control algorithm is formulated based on the Lyapunov stability theory considering the constraints associated with the function of the control device. A boundary layer filter is introduced to eliminate the chattering effect associated with implementation of the controller. As a result, the proposed nonlinear controller takes the form of filtered bang-bang control. The control effect is analyzed through numerical simulations on a three-story model building structure. The results show the applicability of the proposed nonlinear controller to realistic, full scale civil structures.