逆模型驱动的实时混合试验两级自适应时滞补偿方法

Two‑stage adaptive time‑delay compensation method driven by inverse model for RTHS

  • 摘要: 在非线性试件的实时混合试验中,由于试件与加载系统存在相互作用,试件性能的变化可能会导致伺服系统的时滞发生改变。通过对系统时滞进行在线估计,自适应时滞补偿方法可以应用于时变时滞系统的加载控制,但参数的估计值在辨识初期往往会发生显著波动,影响控制效果。为此,提出了逆模型驱动的实时混合试验两级自适应时滞补偿方法,即以系统的逆模型控制器进行粗补偿,消除主要时滞带来的试验误差;以基于递归最小二乘的自适应时滞补偿方法对剩余时滞进行补偿,进一步控制精度。以两层剪切型框架为原型,自复位黏滞阻尼器为试件,对两个试验子结构同时开展时滞补偿实时混合试验。数值模拟和试验结果表明,所提方法的控制精度高于单阶段的时滞补偿方法,并可应用于多试验子结构的实时混合试验。

     

    Abstract: During real‑time hybrid simulation(RTHS) of nonlinear specimens, the interaction between the specimen and the loading system can lead to variations in the specimen’s behavior, consequently affecting the time delay in the servo system. Online estimation of the system’s time delay enables the application of an adaptive time‑delay compensation method for controlling time‑varying systems. Nevertheless, during the initial stages of parameter identification, the estimated values frequently exhibit notable fluctuations, which can have a detrimental impact on the effectiveness of control. To this end, a two‑stage adaptive time‑delay compensation method driven by the inverse model for RTHS is proposed. Firstly, the inverse model controller of the system is used to perform coarse compensation to eliminate the test error caused by the main time delay. Then, the adaptive delay compensation method based on recursive least squares is used to compensate the remaining delay to further control the accuracy. By using the two‑story shear frame as the prototype and the self‑centering viscous dampers as the specimens, a time‑delay compensation RTHS is carried out simultaneously on the two experimental substructures. Numerical simulations and experimental results show that the control accuracy of the proposed method is higher than that of the single‑stage time‑delay compensation method, and it can be applied to RTHS involving multiple experimental substructures.

     

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