Optimal control system design considering damping characteristics of semi-active damper

Abstract

To reduce the absolute acceleration and displacement of buildings during earthquakes, this paper proposes an optimal control system design method considering structural limitation of a semi-active damper. The semi-active damper incorporates a high and low switchable damping coefficient. The limitation is that the semi-active damper is able to generate control force only in the reverse direction of the velocity. In this paper, the structural passive limitation is considered by geometric relationship between the control force and damper velocity, and the area of desired control force is represented to an equation of an ellipse. By calculating the optimal control force within the limitation, an optimal control system that reduces degradation in control performance is realized. Moreover, it is possible to design the control system based on the structural characteristic and geometric configuration without parameter tuning using design seismic wave. The proposed design method is applied to the base isolated single-degree-of-freedom model with semi-active oil dampers. The control performance of the proposed method is verified through simulation using several kinds of seismic waves.

Keywords

• semi-active control
• optimal control
• variable damper
• seismic isolation
• vibration control