Semiactive Control of Earthquake/Wind Excited Buildings Using Output Feedback☆

Abstract Output feedback control using Magnetorheological dampers and Variable Stiffness Tuned Mass Dampers is considered. Firstly, seismic response control of a building with MR dampers is considered. Optimal Static Output Feedback (OSOF) control yields the desired control force. Two laws are proposed to obtain voltage that achieves the desired force. OSOF yields a reduction in responses and CPU time vis-a-vis LQG and Passive-on controllers. Instantaneous Optimal Control is also considered. Next, a stiff and a flexible building are connected by a MR damper. Input voltage is predicted by a Recurrent Neural Network using desired control force from LQG/OSOF. Both output feedback controllers yield significant reduction in response and base shear and require much less control effort compared to passive-on control. Lateral-torsional seismic response control of plan asymmetric buildings connected by MR dampers is also studied. Finally, control of a wind excited benchmark building using a Variable Stiffness TMD is considered. The nominal stiffness corresponds to the fundamental frequency, resulting in an LTI system for which the desired control force is computed using OSOF/LQG control. A simple control law yields the device configuration. The present control is comparable with active-TMD and better than Short-time-Fourier-Transform control. A variable length pendulum TMD is proposed.