Vibration Control in a Triple Flexible Structures. Basic Study for Realizing Ultratall Buildings.

Abstract

We propose a vibration control method for triple flexible structures. In recent years, tall buildings have been equipped with active dynamic absorbers in order to maintain living comfort because the absorbers reduce the vibration of the higher floors due to strong winds. However, these absorbers are not suitable for vibration control of ultratall buildings because it is difficult to obtain sufficient control force under the low frequency. We propose a new control method to overcome this problem. In which a group of two or three ultratall buildings are controlled actively by means of actuators placed between them. Thus, it is possible to obtain sufficient control force at low frequency. In this paper, a modeling procedure is proposed using uncontrollability and unobservability and a digital filtering technique to prevent spillover instability. The model is a reduced-order model for control objects, each expressed by a 2DOF system to control each of the first and second bending modes. LQ control theory is applied to the design of the control system including the filter. The effectiveness of the proposed method is demomstrated theoretically and experimentally.