H∞Active Seismic Response Control Using Static Output Feedback

This paper presents robust H∞ control for civil engineering structures using static output feedback. Within the H∞ framework, controllers which lead to desirable performance are obtained, using a limited number of sensors but without observers. In addition, the closed-loop system can be designed to be robust with respect to potentially time-varying, structured uncertainties in the system. We do not use state feedback or estimates of the state in our controller, and only use the measured output from a limited number of sensors installed at strategic locations. Necessary and sufficient conditions are presented, which guarantee stability and disturbance attenuation for all admissible uncertainties via static output feedback control. The effectiveness of such controllers is illustrated through simulations of the responses of a three-story and a six-story building under seismic excitation. The results indicate that significant reductions in the building response can be achieved with a limited number of sensor measurements.