DESIGN METHOD FOR BASE-ISOLATION STRUCTURE COMBINED WITH ACTIVE CONTROL BASED ON THE LIMITATION CONDITIONS OF THE RESPONSES AND CONTROL FORCE

Abstract

The linear quadratic regulator (LQR) is widely used in active structural controls (ASCs). However, at the present stage, the influence of the design parameters (LQR weighing matrices) on the vibration characteristics of the control system has not been explicitly expressed. In particular, the estimation of the required control force has not been conducted. Therefore, the LQR weighting matrices are mainly selected by trial and error approach, making it very difficult to design a control system that achieves the desired performance. To solve this problem, an equivalent model of the single-degree-of-freedom active model (structure with active control) is constructed, using which, a calculation method for the weighing matrices that does not require a trial and error approach to satisfy the desired control performance is proposed. Thereafter, the concept of the transitional response spectrum, which is widely used in structural design, is promoted as a control force spectrum that can be used to estimate the maximum control force. Finally, the design of a passive base isolation (PBI) reactor is discussed as an example, and the performance-oriented design method for the PBI structure combined with ASC is proposed that simultaneously satisfies the limitation conditions of the responses and control force.