Active Vibration Control of Flexible Structures Arranged in Parallel

Abstract

This paper proposes a vibration control method for flexible structures arranged in parallel. In recent years, tall buildings equipped with active dynamic absorbers have been popularized to maintain living comfort by reducing the vibration of higher floors by strong winds. The higher a tall building the lower its natural frequency. It will be difficult to control the vibration of ultra-tall buildings using active dynamic absorbers because of difficulties in obtaining enough control force under the lower frequency. According to the proposed method, a pair of flexible buildings are controlled actively by controlling each other by means of actuators placed between them. Therefore, it is able to obtain enough control force under the low frequency. In this paper, a reduced-order model expressed by 2DOF systems is proposed for preventing spillover instability. The LQ control theory is applied to the design of the control system. The effectiveness of this method is demonstrated theoretically as well as experimentally.