地震模拟振动台控制系统的发展

地震模拟振动台试验多采用离线迭代控制(ICS)实现波形的高精度复现，然而，多次迭代将对易损试验体造成累积损伤，同时，非线性试验体连续变化的动力特性将导致离线迭代控制出现精度下降的问题。针对上述问题，提出了一种基于系统矩阵修正的高精度在线迭代控制方法(HRICS)。该方法利用地震动加载过程中的实测数据在线识别系统矩阵，进而选择修正策略，并采用矩阵精度评价指标评估系统矩阵识别精度，若满足精度要求，则采用基于帧或者频率点的修正策略更新系统矩阵，最终使响应信号能够高精度地复现目标波形。通过振动台模型试验验证HRICS方法的有效性，并通过数值模拟研究HRICS方法的在非线性试验体下的控制性能。试验结果表明：HRICS采用频率点修正策略能获得最佳的控制效果；HRICS方法对目标信号的再现精度明显高于ICS方法第一次迭代后的结果。

Recent progress on control techniques of shaking table and array systems in China: An overview

Offline iterative control (ICS) is often used in shaking table test to accurately reproduce earthquake waveform. However, multiple iterations will cause cumulative damages to vulnerable test specimens, and the continuously changing dynamic characteristics of the nonlinear test specimen will also lead to decrease of control accuracy of the ICS. To solve the problems, a high-accuracy real-time iterative control method (HRICS) based on system matrix correction is proposed. This method identifies the system matrix online upon the real-time data measured during the loading process, then selects the correction strategy accordingly, and finally evaluates the identification accuracy of system matrix by matrix accuracy evaluation indices. If the system matrix accuracy meets the requirement, the system matrix is updated upon frames or frequency points correction strategy, so that the response signal can reproduce the target waveform with high accuracy. The HRICS method is attested by shaking table test, and the control performance under nonlinear test body is studied by numerical simulation. The results indicate that the HRICS method using the frequency point correction strategy shows the best control effect. The reproduction accuracy of the HRICS method is significantly better than that of the ICS method after its first iteration.