为有效处理结构参数和激励荷载不确定等因素的影响,基于相平面分析,提出了一种分级控制法.将相平面划分成若干局部网格区域,使与被控质点运动状态对应的任一轨迹点映射到某一局部网格区域.根据对应的网格区域可判定质点的运动趋势,然后设计出相应的控制力.通过算例研究了一个底层设有主动拉索系统(ATS)的三层剪切型结构的地震反应控制问题,验证了建议控制律的有效性.数值结果显示,与无控状况相比,建议算法可以显著减少结构的地震反应,同时其控制性能也要略优于线性二次型定常状态调节器(LQR)控制.
To deal efficiently with imprecise and uncertain data associated with structural parameters and exciting loads, a multilevel control method was presented for vibration control of structures based on phase plane analysis. The phase plane was divided into many local grid regions, and the trajectory point corresponding to any instantaneous motion state of the controlled mass could be mapped to a grid region. The control force was obtained by distinguishing the motion trend of the controlled mass. Effectiveness of the proposed algorithm was demonstrated through a numerical example which considered a three-storey structure controlled with the active tendon system (ATS) installed in the first storey. Numerical results show that the proposed algorithm results in significant decrease in the seismic response of the structure when compared to the uncontrolled case, and the control performance of the algorithm is also superior to that of the linear quadratic regulator (LQR) algorithm.