Nonstationary Vibration Control for Buildings by Using Time-Varying Weight.

Abstract

There are many studies on vibration control for building using an active dynamic absorber. When applying active vibration control, it is most important problem to achieve higher performance within a certain constraint on actuator. However, it is difficult to solve this problem by using a stationary controller because seismic wave has nonstationary characteristics. This study presents a controller design method based on the nonstationary optimal control. In this technique, the characteristics of nonstationary intensity such as a seismic wave is considered by using the time-varying criterion function. Time-varying weight corresponds to the envelop function which gives noncriterion function. Time-varying weight corresponds to the envelop function which gives non stationary intensity of a seismic wave. And this controller is designed by solving the time-varying Riccati equations. By considering uncertain characteristics of seismic wave, a modification method is presented, in which the time varying feedback gain is varied continuously depending on the mean square value of seismic wave. To compare the performance with a stationary control, numerical calculations and simulations were carried out. As a result, the effectiveness of nonstationary optimal control was shown.