Active Control Effect by Mass Driver System to Urban Important Structures during Earthquake

新的控制算法已被引入到一个模型的八层建筑，以证明减少由中等地震引起的振动。在4 m × 4 m的振动台上进行了正弦激振试验、非平稳随机波激振试验和埃尔森特罗NS地震波激振试验。研制了一种安装在模型结构顶层的主动动力质量阻尼系统，该系统由交流伺服电机通过滚珠丝杠驱动。考虑到AMD的动态特性与驱动质量为1。kgf。通过对模型框架结构进行数字计算机控制试验和数值计算，得到了所提出的开-闭控制算法具有良好的控制效果，有很大的可能用于实际结构的地震反应控制。（1）控制参数对系统响应的影响用两个独立变量表示。一个控制反馈的水平，另一个反映输入激励的水平。对于一个给定的结构系统，我们发现，有适当的控制参数，以最大限度地提高控制效率。从模态控制算法，我们推导出最佳前馈增益抵消激励项。(2)实验研究结果表明，所提出的闭环控制算法比闭环控制算法具有更好的控制效率，实际结构的地震响应控制是可能的。

The new control algorithm has been introduced to a model eight-story building to demonstrate reduction of vibrations caused by medium earthquakes. As forced vibration tests, sinusoidal excitation to identify the dynamic characteristics of the model structure, non-stationary random wave excitation tests using filtered white noise wave as well as EL Centro NS seismic wave were carried out on a 4m by 4m shaking table. An active dynamic mass damping system installed at the top floor of model structure driven by an AC servomotor through a ball screw was developed. The optimization of the controller is performed taking into account the dynamic characteristics of AMD with the driving mass of 1. kgf. By carrying out digital computer-controlled tests and numerical calculations using the model frame structure, we have obtained that the proposed open-closed control algorithms could perform good control efficiencies and there is an ample possibility for them to be used for seismic response control of actual structures.The principle results of digital computer-controlled tests and numerical calculations using the model frame structure are summarized as follows :(1) Effects of the control parameters on the system's response are expressed by two independent variables. One controls the level of feedback, the other reflects the level of input excitation. For a given structural system we found that there are appropriate control parameters to maximize the control efficiencies. From the modal control algorithm, we derived the optimal feedforward gain to offset the excitation term.(2) Results of the experimental studies done to examine the applicability of the developed optimal control algorithm to an active mass driver system driven by an AC servomotor showed that the proposed closed-open-loop control algorithm gave better control efficiencies than the closed-loop control algorithm and that the seismic response control of actual structures is possible by using them.