Optimum control of a hybrid system for seismic excitations with state observer technique

This paper presents a theoretical study of a hybrid seismic response control system comprising a passive fluid viscous damper and an active control system with a hydraulic actuator and acceleration sensors. The analytical model of this system is derived in the discrete time domain with actuator and damper dynamics considered. Based on digital control theory, a state observer is established for optimal control strategies of the hybrid system. This study shows that the hybrid system gains the advantages of both active and passive control techniques currently in vogue; and that, with the state observer technique, a seismic response control system is more effective and less complicated because full-state feedback seismic control algorithms can be implemented by means of acceleration sensors, and a smaller number of sensors is required. A numerical simulation for seismic response of a building structure with a hybrid control system is presented to demonstrate the effectiveness of this control strategy for the hybrid system.