Comparison of Adaptive Sliding Mode Controllers in Earthquake Induced Vibrations

Abstract

This study aims to reduce earthquake-related vibrations in buildings. This is achieved by designing two different robust adaptive control algorithms to control the damping force of the dampers. This design is used in mitigating the structural vibrations of a three-story prototype building exposed to two different scaled earthquakes. Two cases are considered where two damping systems are employed and mounted on the top floor: an Active Tuned Mass Damper (ATMD), the second damper is a semi-active Magnetorheological Damper (MRD). The first damper depends entirely on the control algorithm to correct structural movement; the second one operates as a passive damper under minor vibrations and becomes active under stronger vibrations. The results showed that one of the adaptive algorithms give a better displacement reduction and error indices across all floors. Furthermore, integrating that controller with MRD demonstrated higher accuracy in tracking the structural response with less control effort compared to ATMD. To validate the method effectiveness, it was compared to another robust sliding mode controller from the literature. The results show a significant improvement in displacement reduction and less control effort by 40.23% better than the control effort of the previous work. These findings highlight the potential of combining advanced control strategies with semi-active damping systems for effective vibration mitigation and energy efficiency.