Civil structures semi-active control with limited measurements

A control scheme to protect civil structures against earthquake induced damage that uses magnetorheological dampers as control devices is presented. The design of the scheme is based on a LuGre´s dynamic friction model adapted to better describe the behavior of magnetorheological dampers and an adaptive observer that estimates the damper parameters and the structure stories positions and velocities, based on acceleration and force measurements. A linear matrix inequality approach is used to design the adaptive observer, while the design of the structure motion controller is developed with Lyapunov techniques. Seismic attenuation with respect to the case of non-controlled structures is demonstrated by numerical simulations.