Active Control of Large Scale Structure Systems under Earthquake Excitations

针对地震作用下结构控制的具体应用，对经典最优控制算法进行了评述。当地震地面加速度作为连续外扰的主要来源时，Riccati闭环控制不满足最优条件。本文提出了一种新的瞬时闭环开环最优控制算法，该算法通过最小化结构系统的二次时变性能指标和输入地震能量之和来推导。本文提出了三种最优控制算法，分别考虑了结构系统的非线性、土-结构动力相互作用效应和控制力作用的时滞效应。在一般动荷载作用下，这些优化算法简单可靠，可用于在线控制，对基础隔震结构体系是有效的。详细研究了性能指标中两个加权矩阵对控制效率的影响。数值算例验证了该控制算法的有效性。

A critical review of classical optimal control algorithms is made withrespect to the specific application of structural control under seismic excitations. With the earthquake ground acceleration being the major source of continuous external disturbances, the Riccati closed-loop control does not satisfy the optimal condition. A new instantaneous closed-open-loop optimal control algorithms is proposed herein, which is derived by minimizing the sum of the quadratic time-dependent performance index and the input seismic energy to the structure system. This new control law is developed for providing feasible control algorithms that can easily be implemented for applications to seismic-excited structures.In this report we developed tree optimal control algorithms taking into account the non-linearity of structure system, the dynamic soil-structure interaction effect and the effect of time delay for applying contorol force to the structural system. Subjected to general dynamic loads, these optimal algorithms are simple and reliable for on-line control operations and they are effective for a structural system with base isolation mechanism. We investigate in detal the control efficiency which is affected by the two weighting matrics included in the performance index. Numerical examples are worked out to demonstrate the control efficiency of the proposed control algorithm.